State of Illinois
Pat Quinn, Governor
Department of Public Health
Damon T. Arnold, M.D., M.P.H., Director
The Epidemiology of
Infectious Diseases in
Illinois, 2007
The Epidemiology of Infectious Diseases in Illinois, 2007
TABLE OF CONTENTS
Reportable Communicable Diseases in Illinois . .......... ......... .......... .......... ........1
2007 Summary of Selected Illinois Infectious Diseases ......... .......... .......... ........3
Acquired Immune Deficiency Syndrome/Human Immunodeficiency Virus .. ........6
Amebiasis.... .......... .......... .................... .......... .......... ......... .......... .......... ......10
Babesiosis ... .......... .......... .................... .......... .......... ......... .......... .......... ......12
Blastomycosis ........ .......... .................... .......... .......... ......... .......... .......... ......13
Botulism ...... .......... .......... .................... .......... .......... ......... .......... .......... ......15
Brucellosis ... .......... .......... .................... .......... .......... ......... .......... .......... ......18
Campylobacteriosis .......... .................... .......... .......... ......... .......... .......... ......21
Central Nervous System Infections ........ .......... .......... ......... .......... .......... ......24
Aseptic Meningitis or Encephalitis of Unknown Etiology ......... .......... ......25
Aseptic Meningitis or Encephalitis of Known Etiology,
Excluding Arboviruses ................. .......... .......... ......... .......... .......... ......27
Arboviral Infections ... .................... .......... .......... ......... .......... .......... ......29
Haemophilus influenzae (Invasive Disease) ........ ......... .......... .......... ......37
Listeriosis ...... .......... .................... .......... .......... ......... .......... .......... ......40
Neisseria meningitidis, Invasive .... .......... .......... ......... .......... .......... ......43
Streptococcus,Group B, Invasive .. .......... .......... ......... .......... .......... ......47
Cryptosporidiosis .... .......... .................... .......... .......... ......... .......... .......... ......49
Cyclosporiasis ........ .......... .................... .......... .......... ......... .......... .......... ......53
Ehrlichiosis .. .......... .......... .................... .......... .......... ......... .......... .......... ......54
Shiga Toxin Producing E. coli, Enterotoxigenic E. coli, Enteropathogenic
E. coli .......... .......... .................... .......... .......... ......... .......... .......... ......58
Foodborne and Waterborne outbreaks... .......... .......... ......... .......... .......... ......63
Giardiasis .... .......... .......... .................... .......... .......... ......... .......... .......... ......92
Hansen’s Disease (Leprosy) .................. .......... .......... ......... .......... .......... ......95
Hemolytic Uremic Syndrome .................. .......... .......... ......... .......... .......... ......96
Hepatitis A ... .......... .......... .................... .......... .......... ......... .......... .......... ......98
Hepatitis B ... .......... .......... .................... .......... .......... ......... .......... .......... ....102
Hepatitis C, Acute... .......... .................... .......... .......... ......... .......... .......... ....105
Hepatitis C, Chronic or Resolved ........... .......... .......... ......... .......... .......... ....108
Histoplasmosis ....... .......... .................... .......... .......... ......... .......... .......... ....110
Influenza, Novel ..... .......... .................... .......... .......... ......... .......... .......... ....113
Influenza-associated Pediatric Mortality (< 18 years) ... ......... .......... .......... ....114
Legionellosis .......... .......... .................... .......... .......... ......... .......... .......... ....115
Lyme Disease ........ .......... .................... .......... .......... ......... .......... .......... ....118
Malaria ........ .......... .......... .................... .......... .......... ......... .......... .......... ....123
Measles ....... .......... .......... .................... .......... .......... ......... .......... .......... ....128
Mumps ........ .......... .......... .................... .......... .......... ......... .......... .......... ....130
Pertussis ..... .......... .......... .................... .......... .......... ......... .......... .......... ....133
Q Fever ....... .......... .......... .................... .......... .......... ......... .......... .......... ....136
Rabies ......... .......... .......... .................... .......... .......... ......... .......... .......... ....138
Rabies, Potential Human Exposure ....... .......... .......... ......... .......... .......... ....154
Rocky Mountain Spotted Fever .............. .......... .......... ......... .......... .......... ....159
Salmonellosis (Non-Typhoidal) .............. .......... .......... ......... .......... .......... ....162
Sexually Transmitted Diseases .............. .......... .......... .. …… .......... .......... ....172
Chlamydia .. .......... .................... .......... .......... ......... .......... .......... ....172
Gonorrhea ... .......... .................... .......... .......... ......... .......... .......... ....174
Syphilis ........ .......... .................... .......... .......... ......... .......... .......... ....176
Shigellosis ... .......... .......... .................... .......... .......... ......... .......... .......... ....179
Staphylococcus aureus, Intermediate or High Level Resistance....... .......... ....185
Streptococcus pyogenes, Group A (Invasive Disease) ......... .......... .......... ....186
S. pneumoniae, Invasive ... .................... .......... .......... ......... .......... .......... ....189
Tetanus ....... .......... .......... .................... .......... .......... ......... .......... .......... ....192
Tick-borne Diseases Found in Illinois ..... .......... .......... ......... .......... .......... ....193
Toxic Shock Syndrome Due to Staphylococcus aureus ......... .......... .......... ....195
Tuberculosis .......... .......... .................... .......... .......... ......... .......... .......... ....197
Tularemia .... .......... .......... .................... .......... .......... ......... .......... .......... ....201
Typhoid Fever ........ .......... .................... .......... .......... ......... .......... .......... ....203
Varicella ...... .......... .......... .................... .......... .......... ......... .......... .......... ....205
Vibrio, Non-cholera. .......... .................... .......... .......... ......... .......... .......... ....207
Yersiniosis ... .......... .......... .................... .......... .......... ......... .......... .......... ....209
Non-foodborne Non-Waterborne Outbreaks, 2007 ...... ......... .......... .......... ....212
Other Incidents Occurring in 2007 .......... .......... .......... ......... .......... .......... ....234
Reported Cases of Infectious Diseases in Illinois, 2007 ......... .......... .......... ....236
Methods ...... .......... .......... .................... .......... .......... ......... .......... .......... ....237
Reportable Communicable Diseases in Illinois
The following diseases must be reported to local health authorities in Illinois (those in bold are also nationally
notifiable, which means reportable by the state health department to the U.S. Centers for Disease Control and
Prevention):
CLASS 1(a) - The following diseases are reportable by telephone immediately (within three hours):
1.
Anthrax
5.
Smallpox
2.
Botulism, foodborne
6.
Tularemia
3.
Plague
7.
Any suspected bioterrorist threat
4.
Q-fever
or event
CLASS 1(b) -The following diseases are reportable within 24 hours of diagnosis:
1. Botulism, infant, wound, and other
12.
Measles
2. Cholera
13.
Pertussis
3. Diarrhea of the newborn
14.
Poliomyelitis
4. Diphtheria
15.
Rabies, human
5. Foodborne or waterborne illness
16.
Rabies, potential human
exposure
6. Hemolytic uremic syndrome, post-diarrheal
17.
Typhoid fever
7. Hepatitis A
18.
Typhus
8. Any unusual case or cluster of cases that may
19.
Enteric Escherichia coli infections
indicate a public health hazard
(E. coli)0157:H7 and other
9. Haemophilus influenzae, meningitis and other
enterohemorrhagic E. coli,
invasive disease
enterotoxigenic E. coli)
10. Neisseria meningitidis. Meningitis and invasive
enteropathogenic E. coli)
20.
Staphylococcus aureus infections with
disease
11. Streptococcal infections, Group A, invasive
intermediate or high level
(Including toxic shock syndrome) and sequelae
resistance to vancomycin
to group A streptococcal infections (rheumatic
fever and acute glomerulonephritis)
(Continued on attached page)
1
CLASS II-The following diseases shall be reported as soon as possible during normal business hours, but
within seven days (exceptions to the seven-day notification requirement are marked with an asterisk; see
note below.)
1.
AIDS
27.
Malaria
2.
Amebiasis
28.
Meningitis, aseptic (including arbovirus infection)
3.
Blastomycosis
29.
Mumps
4.
Brucellosis
30.
Ophthalmia neonatorum (gonococcal)*
5.
Campylobacteriosis
31.
Psittacosis
6.
Chanchroid*
32.
Reye’s syndrome
7.
Chickenpox
33.
Rocky Mountain spotted fever
8.
Chlamydia*
34.
Rubella, including congenital
9.
Cryptosporidiosis
35.
Salmonellosis (other than typhoid)
10.
Cyclosporiasis
36.
Shigellosis
11.
Ehrlichiosis, human
37.
Staphylococcus aureus infection, toxic shock
granulocytic
syndrome
12.
Ehrlichiosis, human
38.
Staphylococcus aureus infections occurring in
monocytic
infants under 28 days of age (within a health care
13.
Encephalitis
care institution or with onset after discharge)
14.
Giardiasis
39.
Streptococcal infections, group B, invasive disease,
15.
Gonorrhea*
of the newborn
16.
Hantavirus pulmonary
40.
Streptococcus pneumoniae, invasive disease
syndrome
(including antibiotic susceptibility test results)
17.
Hepatitis B
41.
Syphilis*
18.
Hepatitis C
42.
Tetanus
19.
Hepatitis, viral, other
43.
Trichinosis
20.
Histoplasmosis
44.
Tuberculosis
1
45.
Yersiniosis
21.
HIV infection
22.
Legionnaires’ disease
23.
Leprosy
24.
Leptospirosis
25.
Listeriosis
26.
Lyme disease
*Must be reported by mail or by telephone to the local health authority within five days
The occurrence of any increase in incidence of disease of unknown or unusual etiology should be
reported, with major signs and symptoms listed.
When an epidemic of a disease dangerous to the public health occurs and present rules are not
adequate for its control or prevention, more stringent requirements shall be issued by the Illinois
Department of Public Health.
2
2007 Summary of Selected Illinois Infectious Diseases
In Illinois, the communicable disease (CD) surveillance system relies on the
passive reporting of cases required by state law. Diseases are made reportable
because regular and timely information is necessary for prevention and control efforts.
Lists of notifiable diseases are revised to include new pathogens or delete those with
declining importance. The current reportable disease list mandates reporting, within
specific time frames, of certain diseases and of selected positive laboratory tests.
Surveillance of notifiable diseases provides public health workers the opportunity to
ensure that ill persons receive appropriate treatment, provide contacts with needed
vaccines or other preventive treatments, and halt outbreaks. The effectiveness of the
surveillance system relies heavily on the cooperation and support of health care
providers, laboratories and local health departments in submitting information on
reportable disease cases. In Illinois, regulations require reporting by physicians, nurses,
nurses aides, dentists, health care practitioners, laboratory personnel, school personnel,
long-term care personnel, day care personnel, and university personnel. Notifiable
disease data are submitted by the Illinois Department of Public Health (the Department)
on a weekly basis to be included with national data in the Morbidity and Mortality
Weekly Report (MMWR). CD rules also include laboratory reporting. Some isolates are
required to be forwarded to the Department. For selected agents and situations, pulse
field gel electrophoresis may be performed to subtype isolates.
Four diseases – SARS, smallpox, human influenza caused by a new subtype
and wild type polio - are considered to be a public health emergency of international
concern by the World Health Organization. There are 55 diseases or conditions listed as
nationally reportable to the U.S. Centers for Disease Control and Prevention (CDC).
This number reflects certain combinations; for example, HIV and AIDS are combined
under one category (human immunodeficiency virus/acquired immune deficiency
syndrome [HIV/AIDS]) as are invasive group A streptococcus (GAS) and toxic shock
syndrome due to GAS. Diseases reportable to CDC but not reportable in Illinois include
animal rabies, severe acute respiratory syndrome (SARS), varicella,
coccidioidomycosis, influenza associated pediatric mortality, and yellow fever. Animal
rabies testing only is performed by state laboratories, so reporting is complete through
state laboratory reporting. Other diseases in Illinois of public health importance can be
reported as cases or clusters of unusual illness. Varicella and severe acute respiratory
syndrome reporting in Illinois was mandated in 2008. In 2007, the 10 most frequently
reported notifiable infectious diseases in the United States were chlamydia, giardiasis,
gonorrhea, AIDS, salmonellosis, shigellosis, varicella, Lyme disease, tuberculosis and
syphilis..
In 2007, 65 different types of infectious diseases were reportable to the Illinois
Department of Public Health (see pages 1 and 2). Many of the reportable diseases are
discussed in this annual report along with some non-reportable diseases of importance
in 2007. Case numbers for the various infectious diseases listed in this summary should
be considered minimum estimates. There are several reasons why reported numbers
are lower than the actual incidence of disease: Many individuals do not seek medical
care and thus are not diagnosed; some cases are diagnosed on a clinical basis without
confirmatory or supportive laboratory testing; and among diagnosed cases, some are
3
not reported. These surveillance data are used to evaluate disease distribution
trends over time rather than to identify precisely the total number of cases
occurring in the state.
The five most frequently reported nationally notifiable infectious diseases in Illinois
were chlamydia, gonorrhea, HIV/AIDS, Salmonella and invasive S. pneumoniae.
Diseases with increased reporting in 2007 over the previous five-year median included
amebiasis, Chlamydia, human monocytic ehrlichiosis, human granulocytic anaplasmosis,
other ehrlichia species, giardiasis, S. pneumoniae, Shigella, mumps, Lyme disease, N.
meningitidis, ehrlichiosis, blastomycosis, Listeria, Rocky Mountain spotted fever,
cryptosporidiosis, hepatitis A, histoplasmosis, Legionellosis, pertussis, staphylococcal
toxic shock, and typhoid fever.
The number of reported cases of California encephalitis, West Nile virus, Giardia,
hepatitis A, pertussis, tuberculosis, tularemia, have been decreasing compared to the
previous five-year median.
Highlights of 2007 in Illinois included:
• A large number of complaints about itch mite bites
• A cluster of Q fever cases in slaughterhouse workers
• A foodborne adult lead poisoning cluster
• Reported cases of African tick bite fever cases
• Two reportable cases of novel influenza
• Two reported babesiosis cases exposed outside Illinois
• Two tetanus cases
• A case of excema vaccinatum in a household member of a military person
vaccinated for smallpox
Studies mentioned in the text of this report will be referred to in the selected
readings sections. The reporting of infectious diseases by physicians, laboratory and
hospital personnel, and local health departments is much appreciated. Without the
support of the local health departments in following up on disease reports, it would not
be possible to publish this annual report. The Department hopes you find this information
useful and welcomes any suggestions on additional information that would be of use to
you.
Useful Contact/Surveillance Information
Illinois Department of Public Health website www.idph.state.il.us
To report cases: Contact your local health department.
To refer isolates to the Department lab ship to one of these locations:
Public Health Laboratory; 825 N. Rutledge St., Springfield IL 62761
Public Health Laboratory; 1155 S. Oakland Ave., P.O. Box 2797, Carbondale IL 62901
Public Health Laboratory; 2121 W. Taylor St., Chicago, IL 60612
4
Illinois Counties
5
Acquired Immune Deficiency Syndrome/Human Immunodeficiency Virus
Background
Since the first cases were reported in the summer of 1981, acquired immune
deficiency syndrome (AIDS) has become one of the major health problems to emerge in
the past 25 years. In 1984, the human immunodeficiency virus (HIV) was identified as
the causative agent of AIDS. The disease is spread by the exchange of blood, semen or
vaginal secretions between individuals. The most common routes of transmission are 1)
having sex (anal, oral or vaginal) with an infected person, 2) sharing drug injection
equipment with an infected person (including insulin or steroid needles), and 3) from
mother to infant (perinatal) before or at the time of birth or through breastfeeding.
In 2007, injection drug use (IDU) was the third most frequently reported risk factor
for HIV infection in the United States after male-to-male sexual contact and high-risk
heterosexual contact. From 2004 through 2007, in the United States, the majority of HIVinfected IDUs (62 percent) were male. Many IDUs engage in high-risk behaviors like
sharing syringes and having unprotected sex.
Within weeks to months after infection with HIV, some individuals develop a flulike illness. After this initial illness, individuals with HIV may remain free of clinical signs
for months to years.
Clinical indicators of HIV infection may include lymphadenopathy, chronic
diarrhea, weight loss, fever and fatigue followed by opportunistic infections. HIV may
progress to AIDS, which includes a variety of late-term clinical manifestations including
low T-cell counts. Opportunistic infections associated with AIDS include Pneumocystis
carinii pneumonia, chronic cryptosporidiosis, central nervous system toxoplasmosis,
candidiasis, disseminated cryptococcosis, tuberculosis, disseminated atypical
mycobacteriosis and some forms of cytomegalovirus infection. Some cancers also may
be associated with AIDS (e.g., Kaposi sarcoma, primary B-cell lymphoma of the brain,
invasive cervical cancer and non-Hodgkin’s lymphoma).
Increased knowledge of the disease and improved diagnostic and treatment
methods have led to significant advances in the clinical management of HIV and resulted
in a delay in the progression from HIV to AIDS and a reduction in AIDS morbidity and
mortality. A number of antiretroviral agents are available for treatment of HIV/AIDS, and
combination therapies have been shown to prolong and improve the quality of life for
those who are infected.
At the end of 2007, an estimated 455,636 persons in the United States were living
with AIDS. During 2003 to 2007 the number of new AIDS cases decreased 7.5 percent.
Case definition
The CDC case definition (available on the CDC website) is used for HIV and
AIDS.
Descriptive epidemiology
• Cumulative AIDS cases reported in Illinois (1981 through 2007) – There were 3,682
cases reported.
• Number of AIDS cases reported in calendar year 2007 - The number of reported
AIDS cases rose from 2006 (1,254) to 2007 (1,394). The number of reported HIV
cases was 1,707, a decrease from the 1,876 reported in 2006.
6
•
•
•
•
•
•
Mode of transmission among all AIDS cases reported in Illinois in 2007 is shown in
Figure 1 and for HIV in Figure 2.
The majority of reported AIDS cases in 2007 were in males (1,083 cases or 78
percent). For all cases reported among males, men who have sex with men (MSM)
accounted for the largest number of AIDS cases (596 cases or 55 percent), followed
by injection drug use (IDU) with 122 cases or 11 percent (Figure 3). The majority of
reported HIV cases in 2007 were in males (1,341 or 78 percent). For all cases
reported among males, MSM accounted for the largest number of HIV cases (870
or 65 percent), followed by IDUs with 66 or 5 percent (Figure 4).
Reported cases of AIDS among females accounted for 311 cases or 22 percent of
the total AIDS cases reported in 2007. Among females, heterosexual contact
accounted for 140 cases or 45 percent of the total, with IDU accounting for 65
cases or 21 percent (Figure 5). Reported cases of HIV among females accounted for
one case or 21 percent of the total reported HIV cases in 2007. Among females,
heterosexual contact accounted for 129 cases or 39 percent of the total HIV cases
reported, with IDU accounting for 38 cases or 11 percent (Figure 6).
Non-Hispanic African Americans accounted for 55 percent of the AIDS cases
reported in 2007, followed by 27 percent or white non-Hispanic and 14 percent
Hispanic. For HIV infection, non-Hispanic African Americans accounted for 48
percent of cases, white non-Hispanics accounted for 37 percent and Hispanics for 12
percent.
Heterosexual contact as the mode of transmission accounted for 16 percent, or 225
of all the reported AIDS cases in 2007. It accounted for 11 percent of HIV cases.
In 2007, Cook County and the collar counties (DuPage, Kane, Lake, McHenry and
Will) comprised 87 percent of the total reported AIDS cases. Cook County and the
collar counties comprised 86 percent of the total reported HIV cases.
Summary
There were 1,394 AIDS cases and 1,707 HIV cases reported in Illinois between
January 1 and December 31, 2007. Most reported AIDS and HIV cases involved males.
The most common risk factor for transmission for HIV and AIDS in males was MSM.
Heterosexual contact was the most common risk factor for females with HIV and AIDS,
followed by IDU. The increased number of reported cases of AIDS is probably due to
delays in reporting by healthcare providers.
Figure 1. Reported AIDS Cases in Illinois by Mode of
Transmission, 2007
MSM
23%
Heterosexual
44%
4%
IDU
MSM/IDU
13%
Undetermined/other
16%
7
Figure 2. Reported HIV Cases in Illinois by Mode of Transmission, 2007
MSM
30%
Heterosexual
51%
2%
IDU
MSM/IDU
6%
Undetermined/other
11%
Figure 3. Reported AIDS Cases in Illinois Males by Mode of Transmission,
2007
MSM
20%
Heterosexual
5%
11%
56%
IDU
MSM/IDU
8%
Undetermined/other
Figure 4. Reported HIV Cases in Illinois Males by Mode of Transmission,
2007
MSM
24%
Heterosexual
2%
5%
IDU
65%
MSM/IDU
Undetermined/other
4%
8
Figure 5. Reported AIDS Cases in Illinois Females by Mode of
Transmission, 2007
34%
Heterosexual
45%
IDU
Undetermined/other
21%
Figure 6. Reported HIV Cases in Illinois Females by Mode of
Transmission, 2007
36%
Heterosexual
IDU
54%
Undetermined/other
10%
9
Amebiasis
Background
Entamoeba histolytica is a protozoan parasite that exists in two forms: the cyst
and the trophozoite. It is an important health risk to travelers to the Indian subcontinent,
southern and western Africa, the Far East, and areas of South and Central America.
Intestinal disease can range from mild diarrhea to dysentery with fever, chills, weight loss
and bloody or mucoid diarrhea. Extraintestinal amebiasis also can occur. Persons can
develop amebic liver abscess, which is more common in males than females. This may
occur within two to four weeks of infection and include fever, cough and dull aching
abdominal pain. Some persons are asymptomatic. Humans are the reservoir for
Entamoeba histolytica. Infection occurs when a person ingests fecally contaminated food
or water that contains the cyst or through oral-anal contact. The incubation period ranges
from two to four weeks. In the United States, amebiasis is most commonly seen in
immigrants and travelers to foreign countries.
While examination of stool for ova and parasites often is done, these tests cannot
differentiate E. histolytica from nonpathogenic species like E. dispar and E. moshkovskii.
There are now polymerase chain reaction (PCR) and antigen detection tests which can
be used for differentiation.
Case definition
The CDC case definition used by the Department for a confirmed intestinal
amebiasis case is as follows: a clinically compatible illness that is laboratory confirmed
by demonstration of cysts or trophozoites of E. histolytica in stool, or demonstration of
trophozoites in tissue biopsy or in ulcer scraping by culture or histopathology. The
definition for a case of extraintestinal amebiasis is a parasitologically confirmed infection
of extraintestinal tissue; or, among symptomatic persons with clinical and/or radiographic
findings consistent with extraintestinal infection, demonstration of specific antibody
against E. histolytica as measured by indirect hemagglutination or enzyme-linked
immunosorbent assay (ELISA).
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – 107 (five-year median = 75). All cases
were confirmed. From 2002 to 2007, the number of cases reported per year ranged
from 49 to 107 (Figure 7).
• Age - Cases ranged from birth to 84 years of age (mean = 30 years) (Figure 8).
• Gender - Males accounted for 53 percent of cases.
• Race/ethnicity – Twenty-one percent of cases were white, 57 percent were African
American, with 22 percent reporting some other racial identity; 6 percent of 65 cases
for whom a response is known identified themselves as Hispanic.
• Seasonal variation – There was an increase in cases in April, June, August and
September (Figure 9).
• Geographic location – Ninety of 107 (84 percent) of cases lived in Cook County.
• Clinical outcome – Two of 15 cases with information available were admitted to the
hospital, and none were known to be fatal.
10
Summary
The number of cases in 2007 was higher than the five-year median. Amebiasis
was dropped from the required reporting in Illinois in 2008.
Number of cases
Figure 7 . Amebiasis Cases in Illinois, 2002-2007
150
86
100
107
89
75
75
49
50
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 8. Age Distribution of Amebiasis Cases in Illinois, 2007
30
20
10
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
>59 yr
Age in years
Number of cases
Figure 9. Amebiasis Cases in Illinois by Month, 2007
20
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
11
Aug
Sep
Oct
Nov
Dec
Babesiosis
Background
Babesiosis is a protozoal illness transmitted primarily by Ixodes scapularis ticks in
North America. B. microti, B. duncani and B. divergens-like organisms infect humans. B.
microti is found mainly in the northeast and upper Midwestern states. The incubation
period is from one to six weeks. In Minnesota, onsets of illnesses are usually in July and
August. Babesiosis is usually a self-limiting disease and symptoms include fever,
malaise, myalgia and fatigue. Complications can include congestive heart failure, acute
respiratory failure and renal failure. People at increased risk for complications are those
who are immunocompromised, asplenic, elderly or infected with other tick-borne
pathogens. Patients can harbor the parasite for months or years asymptomatically and
can transmit it through blood products. There is no licensed screening test for
babesiosis in donated blood. Treatment is clindamycin and quinine.
Case definition
A confirmed case is a person with clinically compatible illness and laboratory
positive by blood smear or PCR for Babesia. Probable cases are clinically compatible
with positive serology.
Descriptive epidemiology
Number of cases – Two cases were reported in Illinois residents.
Individual Descriptions
• A woman in her eighties who had traveled to Mexico and Minnesota eight
months prior to illness in September developed fever and dark urine. She
was hospitalized for nine days. She also had multiple blood transfusions in
late July but all donors tested negative. She was laboratory positive for B.
microti infection at CDC. Cases of babesiosis have been acquired in
Minnesota, however, the Minnesota exposure was well prior to the usual
incubation period for this pathogen.
• Another female in her seventies was diagnosed with babesiosis in August
while in Massachusetts. She had a splenectomy as a result of this
infection.
Suggested readings
Gallagher, L.G. et. al. An 84-year-old woman with fever and dark urine. CID
2009;49: 278, 310-311.
Gubernut, D.M., et. al. Babesia infection through blood transfusions: Reports
received by the U.S. Food and Drug Administration, 1997-2007. CID 2009;48:25-30.
12
Blastomycosis
Background
Blastomycosis is most often found in persons living in Midwestern, southeastern
and south central United States and the Canadian provinces that border the Great
Lakes. Occasionally, outbreaks occur in areas outside the endemic areas. The ideal area
for the mycelial form of the organism is soil of warm, moist, wooded areas rich in organic
debris. Recreational activities along waterways are considered to be a major risk factor
for infection. Transmission is usually through inhalation of spore-laden dust.
Blastomycosis most commonly presents as a subacute pulmonary disease but can range
from asymptomatic to disseminated disease. For symptomatic infections, the incubation
period ranges from 30 to 45 days. Blastomycosis is usually localized to the respiratory
tract but can expand to other locations in the body in about 25 to 40 percent of cases.
Persons with moderate to severe pneumonia, disseminated infection or persons infected
who are also immunocompromised need treatment. Diagnosis is through culture, direct
visualization of the organism in cytologic or histologic specimens. There are also
commercial tests for Blastomyces antigen. Urine antigen assays can cross react with
other fungal diseases, such as histoplasmosis. Serologic testing lacks sensitivity and
specificity.
Case definition
The case definition for confirmed blastomycosis in Illinois is culture confirmation of
Blastomyces dermatitidis. If the diagnosis was based on a needle aspirate or other
diagnostic specimen with demonstration of organism resembling Blastomyces or a
presumptive Blastomycosis culture, it is considered a probable case if illness is clinically
compatible.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – 137 (previous five-year median= 91).
All but 12 cases were confirmed. From 2002 to 2007, the number of cases per year
ranged from 87 to 137 (Figure 10). The 2007 incidence rate was 1.1. per 100,000
population in Illinois.
• Age - The mean age was 43 years (range eight to 88) (Figure 11).
• Gender - Seventy-one percent were male.
• Race/ethnicity – Fifty-four percent of the cases were white, 32 percent were African
American, and 14 percent were other races; Twenty-one percent were Hispanic.
• Geographic distribution – Sixty-three percent of the cases had residential addresses
in Cook, Lake or Will counties.
• Seasonal – There appeared to be a slight decrease in cases from July through
September.
• Reporting – Fifty-eight percent of reports were from infection control professionals
and 26 percent from laboratory staff.
• Treatment – Seventy-two percent of cases were hospitalized and two cases were
fatal.
13
Summary
A higher number of blastomycosis cases were reported in 2007 (137 cases) as
compared to the five-year median of 91. This is the highest number of cases reported
since at least 1996. Blastomycosis cases occur predominantly in adults. Many cases had
symptoms of respiratory involvement, including cough, dyspnea or hemoptysis. Among
reported cases, 63 percent of cases reported living in Cook, Lake and Will counties. This
is the last year with full year reporting for blastomycosis.
Suggested readings
Chapman, S.W. Clinical practice guidelines for the management of blastomycosis:
2008 Update by the Infectious Diseases Society of America. Clin Inf Dis 2008;46:180112.
Number of cases
Figure 10. Blastomycosis Cases in Illinois, 2002-2007
150
100
91
89
87
137
119
104
50
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 11 . Blastom ycosis Cases by Age in Illinois, 2007
40
30
20
10
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
Age in years
14
30-39yr
40-49 yr
50-59 yr
>60 yr
Botulism
Background
There are three forms of botulism: foodborne, wound and intestinal (adult and
infant). Botulism toxins cause neuromuscular blockage, which results in flaccid paralysis.
All forms of botulism produce the same distinct clinical syndrome, which includes
symmetrical cranial nerve palsies followed by descending flaccid symmetrical paralysis
that can progress to constipation, respiratory failure, and death. Other symptoms of
botulism include diplopia, blurred vision, abnormal body temperature, and ptosis. As
botulism progresses, the patient retains intellectual function. The absence of cranial
nerve palsies (blurry vision, diplopia, ptosis, facial paralysis, dysphagia, severe dry
mouth) rules out a diagnosis of botulism. Differential diagnoses include myasthenia
gravis and Guillain-Barré syndrome. These can be differentiated using electromyography
(EMG), the pattern of paralysis and reaction to Tensilon.
Foodborne botulism is caused by a neurotoxin produced by Clostridium botulinum
and results from ingestion of preformed toxin present in contaminated food. C. botulinum
is found in soil and aquatic sediments. Seven toxins (A-G) can be produced by C.
botulinum. C. baratii and C. butyricum also can produce some botulinum toxins. Human
cases are caused mainly by toxin types A, B, E and, rarely, F. C. botulinum can form a
spore that survives cooking and food processing measures. Spore germination can
occur during anaerobic conditions, consisting of nonacidic pH and low salt and sugar
content. Botulism toxins are inactivated by heating. Foodborne botulism can occur in
home canned foods and traditional Alaska native dishes. From 1950 through 2005, 405
events of foodborne botulism were identified in the United States where an implicated
food item was identified. Ninety-two percent of events were linked to home-processed
foods and 8 percent to commercially processed foods.
Treatment for foodborne botulism is prompt administration of polyvalent equine
source antitoxin which can decrease progression of paralysis but not reverse existing
paralysis. Equine botulinum antitoxin for types A, B and E can prevent progression of
neurologic disease if administered early in the course of illness.
The most common form of intestinal botulism and of botulism in general is infant
botulism. It occurs in infants younger than one year of age. Infant botulism results when
swallowed spores germinate and temporarily colonize the large intestine. It is believed to
occur because competing organisms are not yet present in the digestive tract. Honey
consumption has been linked to some infant botulism cases but probably only accounts
for about 20 percent of infections. Botulism in infants younger than 12 months of age
should be suspected when constipation, lethargy, poor feeding, weak cry, bulbar palsies,
and failure to thrive are present. Diagnosis of infant botulism involves detection of
botulinum toxin in stool or serum by using a mouse neutralization assay or the isolation
of toxigenic C. botulinum in the feces by enrichment culture techniques. Adult intestinal
botulism is rare and occurs mainly in patients with an anatomical or functional bowel
abnormality or those patients using antimicrobials, which decreases the normal flora to
compete with Clostridium species.
Wound botulism occurs after the causative organism contaminates a wound that
is anaerobic. Wound botulism has increased in recent years due to an increase in
injection drug users, especially those who use heroin. Wound botulism is caused by toxin
elaboration in infected tissue. The mouse bioassay may not detect all clinical cases of
15
wound botulism. Iatrogenic botulism is caused by injection of botulinum toxin for
cosmetic or therapeutic purposes. The doses used for cosmetic treatment are too low to
cause systemic disease.
If botulism is suspected, contact your local health department immediately. This
will allow for rapid investigation to identify the source. If the source was a commercial
product, it can be removed promptly from the market. Laboratory confirmation is still by
the mouse bioassay that is costly, requires an animal facility and takes longer than one
day. Twenty-two public health laboratories in the United States can do the mouse
bioassay. Infant botulism cases have low circulating toxin levels but high stool toxin
levels so stool testing is preferred. Administration of botulinum antitoxin must be done
based on clinical suspicion.
There were 26 cases of foodborne botulism reported in 2007 to CDC. There were
also 91 cases of infant botulism and 22 cases of other types of botulism reported to
CDC. Eleven states reported foodborne botulism cases. Toxin type A accounted for 58
percent of cases, type B for 15 percent and type E for 27 percent. Four outbreaks were
reported. Three were in Alaska and due to beaver tail, seal oil and white fish. The fourth
outbreak was related to contaminated commercial hot dog chili sauce. At least four
cases of botulism were linked. Botulinum toxin type A was identified in leftover chili mix.
Product was recalled after improper canning was identified. Toxin also was identified in
previously unopened cans from the plant and there were many cans that were swollen.
There were 91 cases of infant botulism from 23 states. The toxin types involved
were A (43 percent), B (56 percent) and E (1 percent). The median age of cases was 15
weeks. The wound botulism cases were reported from California and Washington states.
Case definition
Botulism, infant
Clinical illness may include poor feeding, constipation, failure to thrive, and
respiratory failure. The case definition for infant botulism is a clinically compatible case
that is laboratory confirmed, occurring in a child younger than 1 year of age. Laboratory
confirmation is isolation of C. botulinum from stool or detection of botulinum toxin in stool
or serum.
Botulism, foodborne
Clinical illness includes diplopia, blurred vision and bulbar weakness. Symmetric
paralysis may progress quickly. Laboratory confirmation consists of detection of
botulinum toxin in stool, serum or patient ‘s food or isolation of C. botulinum from stool. A
probable case is a clinically compatible case with an epidemiologic link (ingestion of
home-canned food within the previous 48 hours). A confirmed case is a clinically
compatible case that is laboratory confirmed or that occurs among persons who ate the
same food as persons who have laboratory-confirmed botulism.
Botulism, wound
Common symptoms include diplopia, blurred vision and bulbar weakness as well
as symmetric paralysis. Laboratory confirmation is by detection of botulinum toxin in
serum or isolation of C. botulinum from wound. A confirmed case is a clinically
compatible illness that is laboratory confirmed in a patient who has no suspected
16
exposure to contaminated food and who has a history of a fresh, contaminated wound
during the two weeks before symptom onset.
Descriptive epidemiology
• There was one case of infant botulism in Illinois in 2007.
• Individual description
o Type E botulism was identified in specimens from a one-week-old patient from
Dupage County. No food source could be identified as the cause of illness.
Suggested readings
Ginsberg, M.M., et. al. Botulism associated with commercially canned chili sauceTexas and Indiana, July 2007.
Sobel, J. Diagnosis and treatment of botulism: A century later, clinical suspicion
remains the cornerstone. CID 2009; 48:1674-5.
Wheeler, C., et. al. Sensitivity of mouse bioassay in clinical wound botulism. CID
2009;48:1669-73.
17
Brucellosis
Background
Brucellosis is a systemic bacterial infection that affects a wide variety of
mammalian species and is caused by Brucella species. This infection can cause
intermittent or continuous fever and headache, lower back pain, sweating and arthralgia.
Chronic disease can result in abscesses in the liver, spleen, brain, bone or heart valves.
The incubation period varies from two to 10 weeks (range of a few days to six months).
Symptoms can last from days to years. Six major species have been characterized: B.
abortus, B. melitensis, B. suis, B. canis, B. bovis and B. neotomae. Brucella species
considered of importance in human disease include B. abortus (cattle are the primary
reservoir), B. melitensis (sheep and goats are the primary reservoir) and B. suis (swine
are the primary reservoir). Dogs are reservoirs of B. canis but are not considered to be
an important public health concern in the United States. Transmission is by contact with
animal tissues, such as blood, urine, vaginal discharges, aborted fetuses and placentas
and by ingestion of raw milk or other dairy products. Investigation of Brucella cases could
reveal foci of infection in United States livestock that should be investigated and
eliminated. The disease is most common in residents or travelers to the Mediterranean,
Middle East, Mexico, and Central and South America. The large majority of human
Brucella cases are thought to be due to travel outside the country and consumption of
contaminated products from those countries. Consumption of soft cheese from regions
where Brucella is endemic in cattle, sheep and goats is a risk for illness. The risk for
Brucella from dairy products produced in the United States is extremely low. Brucella is
also a Class A bioterrorism agent. Biosafety level 3 is recommended for laboratory
manipulation of isolates. Brucella is the most commonly recognized cause of laboratory
transmitted infection; about 2 percent of all Brucella cases may be laboratory acquired.
The infecting dose for humans is low; the organism can enter the body in many ways
including through the respiratory tract, conjunctivae, through the gastrointestinal tract or
through abraded skin. Laboratory infections have been acquired from sniffing culture
plates and exposure to spills. Most cases of laboratory-acquired infection are from the
more virulent B. melitensis species. Unidentified specimens are often handled on an
open bench, which may result in exposures. When Brucella is suspected, the clinician or
forwarding laboratory should note on the laboratory submission form, “Suspect or rule
out brucellosis” so appropriate precautions can be taken. Antimicrobial treatment must
continue for at least six weeks.
In some developing countries the incidence of brucellosis may be as high as 200
per 100,000, but the disease is rare in the United States. Since 2003, the brucellosis
incidence has increased in the United States. The majority of cases are Hispanic. Fortynine states and three territories were classified as Brucellosis class free for cattle. B.
abortus remains enzootic in elk and bison in Yellowstone Park and B. suis has been
identified in feral swine in the southeastern United States. In the United States in 2007,
131 human brucellosis cases were reported to CDC. Most were in international travelers
or immigrants. Illinois was fifth in the nation in the number of Brucella cases reported.
Case definition
Illinois uses the CDC case definition for brucellosis. The case definition for a
confirmed case of brucellosis is a clinically compatible illness with one of the following
18
laboratory findings: isolation of Brucella from a clinical specimen, a four-fold or greater
rise in Brucella agglutination titer between acute and convalescent phase serum
specimens obtained greater than or equal to two weeks apart and studied at the same
laboratory, or demonstration of Brucella species in a clinical specimen by
immunofluorescence. A probable case is defined as a clinically compatible case that is
epidemiologically linked to a confirmed case or that has supportive serology (i.e.,
Brucella agglutination titer of at least 160 in one or more serum specimens obtained after
symptom onset).
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – Six (five were confirmed, and one was
probable) (See Figure 12). The five-year median was eight cases.
• Age – The mean age of cases was 32 years (range two to 65 years).
• Gender - Two cases were male and four were female.
• Race/ethnicity – Race was known for three cases and all were white; all five cases
with Hispanic status noted were Hispanic.
• Seasonal – Onsets of illness occurred from January to October.
• Geographic distribution by residence – There were four cases in Cook County and
two cases from Kane County.
• Individual Case Descriptions
o Case one – B.melitensis biovar 1 was isolated from a Cook County 10-yearold female in September. The food source was unknown. Laboratory workers
were exposed to the culture and had serial serologies to follow up.
o Cases two and three – These two adult household members, one male and
one female, developed infection from B. melitensis biovar 3. Onsets of illness
were in April and June. The both consumed goat cheese from an unknown
location.
o Case four – A 2-year-old female from Kane County developed infection from
B. abortus biovar 1. She had onset of illness in January and had eaten cheese
from Mexico brought into the United States.
o Case five – This case was a 41-year-old female living in Kane County with
onset of illness in October. B. melitensis biovar 3 was isolated from the
patient. She had eaten cheese brought into the United States from Mexico.
o Case six – A 65-year-old male from Cook County had onset of illness in
January. The case consumed dairy products from Guatemala while traveling.
He had a titer to B. abortus making this case a probable case.
• Diagnosis – Cultures were Brucella positive for five cases. Results for speciation
were identified for five isolates: B. melitensis biovar 1 (one), B. melitensis biovar 3
(three) and B. abortus biovar 1 (one). One probable case had a high titer to B.
abortus.
• Clinical syndrome – Symptoms reported by cases included fever (six cases), weight
loss (two cases) and night sweats (two cases). Four cases were hospitalized. No
deaths were reported.
• Epidemiology – One case with an epidemiologic history reported travel overseas.
Four of these individuals remembered consuming dairy products from other
countries. Two ate goat cheese from an unknown source and one case had an
unknown exposure.
19
•
Laboratory exposures - In November 2007, laboratorians at a clinical laboratory in
Cook County were exposed to a Brucella culture. Five persons were offered
prophylaxis. Four high-risk individuals accepted prophylaxis and one with a low-risk
exposure declined. Twelve female employees had followup serologic testing. Four
sequential serum samples were tested and none tested positive.
Summary
In Illinois, brucellosis is an uncommon disease and tends to occur primarily in
individuals who have recently traveled to foreign countries and consumed unpasteurized
dairy products or who have consumed unpasteurized dairy products imported from
foreign countries. In 2007, there were six brucellosis cases reported in Illinois residents,
which was the fifth highest number among the states reporting cases.
Suggested readings
Glynn, M.K. and Lynn, T.V. Brucellosis. JAVMA 2008;233(6):900-908.
Number of cases
Figure 12. Brucellosis Cases in Illinois, 2002-2007
13
15
10
9
8
7
6
5
0
0
2002
2003
2004
2005
Year
20
2006
2007
Campylobacteriosis
Background
Campylobacteriosis is a zoonotic bacterial enteric disease caused primarily by
Campylobacter jejuni and occasionally by Campylobacter coli. Campylobacter organisms
are motile, gram-negative bacilli with a curved shape. The infectious dose is large. The
incubation period is two to five days. Symptoms may last up to 10 days and include
diarrhea, abdominal pain and fever; however, many infections are asymptomatic.
Sequelae may include reactive arthritis, febrile convulsions, a typhoid-like syndrome,
Guillain-Barré syndrome or meningitis. C. jejuni infection is the most frequently identified
infection preceding Guillain-Barre syndrome. Reactive arthritis can occur seven to 10
days after diarrheal illness. Excretion of the organism can occur for two to seven weeks.
Approximately 1 percent of the population acquires Campylobacter each year in
the United States. Among all 10 diseases under active surveillance in the federal
FoodNet sites (Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS,
Listeria monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica),
infection with Campylobacter comprised 35 percent of all of those reported in 2007. The
overall incidence for this infection from the 10 FoodNet sites was 12.8 per 100,000 in
2007 (range: 7.2 to 28.4). The incidence did not change between 2004-2006 and 2007.
The 2010 national health objective is for 12.3 cases per 100,000.
The reservoir for Campylobacter is animals, most commonly poultry and cattle.
The most important mode of transmission to humans is the consumption and handling of
raw poultry products. Campylobacter is found in approximately 80 percent of retail
chicken meat. Campylobacter is also a cause of traveler’s diarrhea.
A study of enteric infections in Washington state showed that important risk
factors for Campylobacter infections was exposure to aquatic recreation, suboptimal
kitchen hygiene after preparation of raw meat or chicken, consumption of food from
restaurants, domestic travel within the United States, consumption of raw herbs, farm
animals on home property and drinking untreated water.
Prevention of campylobacteriosis includes cooking meat thoroughly, not
consuming unpasteurized milk, avoiding cross-contamination between foods and
handwashing after animal handling.
Case definition
The case definition for a confirmed case of campylobacteriosis in Illinois is a
clinically compatible illness with isolation of Campylobacter from any clinical specimen. A
probable case is a clinically compatible illness that is epidemiologically linked to a
confirmed case.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – 1,277 (previous five-year median =
1294); incidence rate of 10 per 100,000 (Figure 13). All but three were confirmed
cases.
• Gender – Fifty-four percent of cases were male.
• Age – The mean age of reported cases was 39; highest incidence rate occurred in
those 1 to 4 years of age and those 50 to 59 years old. (Figure 14).
• Race/ethnicity - The majority of cases (89 percent) were in whites, with 4 percent in
21
•
•
•
•
•
•
•
African Americans, 4 percent in Asians and 3 percent in other races. Those indicating
Hispanic ethnicity accounted for 13 percent of the cases. There was a significantly
higher proportion of whites with campylobacteriosis and a lower proportion of African
Americans with the disease than in the total Illinois population.
Seasonal variation - Campylobacteriosis was reported more often in the warmer
months of the year in Illinois (June through August) (Figure 15).
Geographic distribution – The five counties reporting the most cases were Cook
(465), Lake (130), DuPage (120), Will (59) and Kane (53).
Clinical – Ninety-eight percent of 588 cases reported diarrhea. Thirty-two percent of
484 cases reported vomiting. Twenty-five percent of 897 reported cases with
hospitalization information were hospitalized. No cases were reported to have died
as a result of this illness.
Campylobacter species identified – The species of Campylobacter was available for
587 cases. The species were identified as jejuni (532 cases), coli (34), lari (16) and
fetus (five).
Risk factors
o Travel – Sixty-one of 371 cases (16 percent) reported travel to another country
prior to onset. Thirty-four of 367 (9 percent) reported travel to another state
prior to onset.
o Animal contact – Information on animal contact was available for 343 cases.
Of these, 190 (6 percent) reported animal contact. Twenty-six cases had
contact with cattle. Contact with dogs was reported for 136 cases and contact
with ill animals was reported for 15 dog owners. Five specifically reported
contact with ill puppies. One individual reported contact with dogs in kennels or
humane societies. Of the 343 cases with animal contact information, 78 cases
reported contact with cats. Twelve of the cases reported contact with cats with
diarrhea with three of these 12 cases reporting contact with kittens with
diarrhea. Seventeen cases had contact with poultry.
Reporting – Seventy percent of cases were reported by personnel from hospitals and
21 percent of cases by commercial or public health laboratory staff.
Outbreaks – One confirmed and one suspect outbreak were reported (see foodborne
outbreak section for details).
Summary
The incidence of the disease in 2007 was 10 per 100,000. This rate was below
the 2010 national objectives of 12 per 100,000. Campylobacter infections occur more
commonly from June through August. The incidence was highest in 1 to 4-year-olds and
50- to 59-year-olds. Whites are more likely to be reported with campylobacteriosis than
other races. This is the last year for full year reporting of campylobacteriosis.
Suggested readings
U.S. Centers for Disease Control and Prevention. FoodNet 2007 Surveillance
Report. Atlanta: U.S. Department of Health and Human Services, 2009.
Denno, D.M., et. al. Tri-county comprehensive assessment of risk factors for
sporadic reportable bacterial enteric infection in children. JID 2009;199:467-476.
22
Number of cases
Figure 13. Campylobacteriosis Cases in Illinois, 2002-2007
1500
1405
1376
1400
1300
1294
1277
1235
1204
1200
1100
2002
2003
2004
2005
2006
2007
Year
Incidence per
100,000
Figure 14 . Incidence of Campylobacteriosis Cases in Illinois by Age,
2007
20
15
10
5
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
>59 yr
Year
Number of cases
Figure 15. Campylobacteriosis Cases in Illinois by Month, 2007
200
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
23
Aug
Sep
Oct
Nov
Dec
Central Nervous System Infections
General
Both aseptic meningitis and acute encephalitis were reportable in Illinois in 2007.
The purpose of this reporting is to identify arboviral infections. Control measures for
arboviruses are possible and include public education and mosquito control activities.
Aseptic meningitis is usually a self-limiting illness characterized by sudden onset
of fever, headache and stiff neck. A rash may be present along with vomiting,
photophobia and nausea. In the United States, enteroviruses cause most cases with
known etiology. Some arboviral infections may present as aseptic meningitis.
Acute infectious and post-infectious encephalitis infections are characterized by
headache, high fever, meningeal signs, stupor, disorientation, coma, tremors,
convulsions or paralysis.
Aseptic meningitis and encephalitis are combined into an unknown etiology and
known etiology category. Arbovirus infections were put in a third section. Cases of each
type of CNS infection are shown in Table 1 and the number of reported CNS infections
by year is shown in Figure 16.
Table 1. Number of Reported CNS Infections Reported in Illinois, 2007
Type of CNS Infection
2007
Aseptic meningitis, unknown
942
etiology
Aseptic meningitis, known
147
virus, not arboviral
Encephalitis, acute, known
23
virus, not arboviral
Encephalitis, acute, unknown
97
etiology
WNV
101
California encephalitis
0
SLE
0
Chikungunya
2
Dengue
0
TOTAL
1,312
# reported
cases
Figure 16. Reported Non-bacterial CNS Infections by Year in Illinois,
2002-2007
3000
2000
1000
0
2147
2002
1528
1480
1632
1293
1312
2003
20 04
2005
2006
2007
Year
24
Aseptic Meningitis or Encephalitis of Unknown Etiology
Background
Both aseptic meningitis and encephalitis were reportable in Illinois in 2007. One of
the purposes of this reporting was to identify arboviruses. Although virus isolation and
serologic testing for arboviruses (during the appropriate season) was offered for free to
health care providers for all persons in the state with aseptic meningitis or encephalitis,
the etiology of many cases of aseptic meningitis and encephalitis remains unknown.
Case definition
The case definition for aseptic meningitis in Illinois is a clinically compatible illness
diagnosed by a physician as aseptic meningitis with elevated white blood cells in the
CSF but no laboratory evidence of bacterial or fungal meningitis. For aseptic meningitis
of unknown etiology, no virus could be isolated from the person and testing for
arboviruses was negative or testing was not done.
The case definition for primary encephalitis is a clinically compatible illness
diagnosed by a physician as primary encephalitis. For encephalitis of unknown etiology,
no virus could be isolated from the patient and there were no positive tests for
arboviruses.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – 1,039 (942 meningitis cases and 97
encephalitis cases).
• Age – The annual incidence rate was highest in those younger than 1 year of age
(118 per 100,000) (Figure 17). In all other age groups, the incidence rate was below
10 per 100,000. The mean age of reported cases was 28.
• Gender – Fifty percent were male.
• Race/ethnicity – Seventy-four percent were white, 16 percent African American and 9
percent other races; 24 percent were Hispanic.
• Seasonal variation – Cases were most common from July through September (Figure
18); Of the total cases, 676 (65 percent) had onsets between May 15 and October 31
(363 cases had onsets outside of this time frame).
• Geographic distribution – The highest number of cases were reported from Cook
(457), Will (109), DuPage (99), Kane (65) and Lake (53).
Summary
Cases of aseptic meningitis and acute encephalitis with no known cause occur
with greater frequency in the summer months and in those younger than 1 year of age.
However, reporting of these infections is required from May 15 through October 31
resulting in an increase in reporting during these months of the year.
25
Incidence per
100,000
Figure 17. Incidence of Aseptic Meningitis and Encephalitis, Unknown
Etiology in Illinois by Age, 2007
150
100
50
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-59 yr
> 59 yr
Age groups
Number of cases
Figure 18. Aseptic Meningitis and Encephalitis, Unknown Etiology by
Month, 2007
200
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Year
26
Aug
Sep
Oct
Nov
Dec
Aseptic Meningitis or Encephalitis of Known Etiology, Excluding Arboviruses
Background
Both aseptic meningitis and encephalitis were reportable in Illinois in 2007. One of
the purposes of this reporting was to identify arboviruses. Virus isolation is offered to all
health care providers of persons in the state with aseptic meningitis or encephalitis, and
this helps to identify the etiology of some cases.
Encephalitis can be caused by infectious, postinfectious and postimmunization
causes. Pathogens causing infectious encephalitis include herpes simplex virus,
arboviruses, lymphocytic choriomeningitis, mumps, cytomegalovirus, Epstein-Barr virus,
human herpesvirus 6 and enteroviruses. Herpes simplex is a common cause of acute
encephalitis that occurs most frequently in children and the elderly. Many encephalitis
cases in the United States and Illinois are not identified as to the etiology.
Aseptic meningitis is an inflammation of the meninges that cover the brain and
spinal cord. It is often caused by a virus, frequently an enterovirus. Enterovirus activity
usually peaks during summer and early fall. Enterovirus illness is usually mild and only a
small proportion result in aseptic meningitis. Children are at greater risk of severe
manifestations with enteroviruses. Adults with enterovirus are more likely to experience
upper respiratory symptoms. Enterovirus is shed in saliva and feces of infected persons.
Persons should wash their hands thoroughly after using the bathroom and avoid sharing
drinks and utensils during an outbreak.
Enterovirus infections are not nationally notifiable. Serotypes of human
enteroviruses include echoviruses, coxsackieviruses and polioviruses.
Case definition
The case definition for aseptic meningitis in Illinois is a clinically compatible illness
diagnosed by a physician as aseptic meningitis with elevated white blood cells (greater
than four cells) in the CSF but no laboratory evidence of bacterial or fungal meningitis.
For aseptic meningitis of known etiology, a virus could be isolated from the person and
no arbovirus testing was positive in specimens from the person.
The case definition for primary encephalitis is a clinically compatible illness
diagnosed by a physician as primary encephalitis. For encephalitis of known etiology, a
virus could be isolated from the patient and there was no positive test for arboviruses.
Descriptive epidemiology
• Number of cases – 170 cases were reported (147 meningitis and 23
encephalitis).
• Age – The mean age was 23 years.
• Gender – Forty-eight percent of cases were male.
• Race/ethnicity – Seventy-two percent were white, 19 percent African American
and 8 percent other races; 21 percent were Hispanic.
• Seasonal variation - Aseptic meningitis or encephalitis of known etiology,
excluding arboviruses were most commonly reported from July through
September (Figure 19). Of the 170 cases, 132 (78 percent) had onsets during
arbovirus season from May 15 through October 31.
• Geographic – The counties reporting the highest number of cases were Cook
(75), Dupage (11) and Will (10).
27
•
Diagnosis – Viruses identified as the etiologic agent were enterovirus, not
further specified (90), herpes simplex (43), coxsackie B1 (two), coxsackie A4
(one), echovirus 6 (one), echovirus, not further specified (two),
cytomegalovirus (one), post cytomegalovirus (one), post Epstein Barr virus
(two), post varicella zoster (11), other or unknown (eight). Other types of
organisms reported as etiologic agents included Cryptococcus (eight).
Summary
In 273 of 1,312 (21 percent) of encephalitis and aseptic meningitis cases, an
etiologic agent (including arboviruses) was identified as the cause of illness.
Enteroviruses, not further specified and herpes simplex were the most common viruses
identified as the causative agents for aseptic meningitis and encephalitis cases.
Arbovirus cases are described in a later section.
Number of cases
Figure 19. Aseptic Meningitis and Encephalitis, Non-Arbovirus, Known
Etiology by Month, 2007
40
30
20
10
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Year
28
Aug
Sep
Oct
Nov
Dec
Arboviral Infections
Background
Arboviruses that cause encephalitis are members of the Togaviridae, Flaviviridae
or Bunyaviridae families. Humans and domestic animals, such as horses, can develop
clinical disease but are usually dead-end hosts because they do not develop sufficient
viremia to contribute to the transmission cycle. Arboviral infections that have ever been
reported in Illinois residents due to exposure in Illinois include those due to St. Louis
encephalitis (SLE), West Nile virus (WNV), California encephalitis (CE) and Western
equine encephalitis (WEE) viruses. WEE has not been seen in Illinois since the 1960s.
The most likely mosquito-borne diseases to occur in people in Illinois as of 2004 are
WNV and CE.
WNV
WNV is a flavivirus in the Japanese encephalitis antigenic complex. Birds become
infected from mosquitoes. Bird-to-bird transmission also may occur. WNV is maintained
in a bird-mosquito-bird cycle with passerine birds as the primary amplifiers. Mosquitoes
from the Culex genus are the primary WNV vectors. The incubation period for WNV is
three to 14 days in people. WNV can cause a wide variety of clinical syndromes,
including fever, meningitis, encephalitis and a flaccid paralysis characteristic of a
poliomyelitis-like syndrome. Febrile illness (fever, headache, fatigue, backache, myalgia)
is not uncommon. Gastrointestinal symptoms and a rash also may occur. The rash is
usually maculopapular and appears between days five to 12 of illness. WNV produces a
viremia that tends to disappear with the onset of clinical symptoms. West Nile
encephalitis occurs more often in persons with immunosuppression or persons greater
than 55 years of age. IgM antibodies can persist for up to a year following infection.
In recent epidemics almost 80 percent of infections were asymptomatic and 20
percent were WNV fever and less than 1 percent were neuroinvasive. Approximately 25
to 50 percent of persons will have rash. There is still a low prevalence of antibodies in
persons in the United States even in locations with intense transmission. Nonavian
species with WNV in the United States have included llamas, wolves, horses, dogs, cats,
skunks, bats and squirrels.
In the United States, almost 90 percent of cases were reported from July through
September. Fifty-nine percent of cases were in males. The median age was 57 years.
Eight-nine percent of patients were hospitalized. Ten percent of cases died. Sixty-two
percent of neuroinvasive cases were encephalitis, 37 percent were meningitis and 5
percent were acute flaccid paralysis.
In the United States, total human cases reported to CDC by year are as follows,
2000 (21), 2001 (66), 2002 (4,156), 2003 (9,862), 2004 (1,604) and 2005 (3,000) and
2006 (4,261) and 2007 (3,630). In 2007, 1,217 neuroinvasive and 2,413 nonneuroinvasive human WNV cases were reported in the United States from 43 states with
124 deaths reported. The incidence rate was 0.4 per 100,000. Thirty-three percent of
cases were neuroinvasive. The peak was in the first week of August. There were 2,182
birds, 8,125 mosquito pools, and 507 horses positive for WNV in the United States in
2007. Corvids were 77 percent of the positive birds. Ninety-three percent of cases in
nonhuman mammals occurred in equines.
29
California encephalitis (CE), Saint Louis encephalitis (SLE) and other U.S.
acquired arboviruses
CE virus is the main cause of pediatric encephalitis in the United States. Severe
illness occurs most commonly in children younger than 15 years of age. The majority of
CE infected persons have no symptoms or a mild febrile illness. Only about 1 percent to
4 percent of infected persons develop any symptoms. In Illinois, cases of CE virus
infection are most often reported from Peoria, Tazewell and Woodford counties. The
main vector is thought to be Ochlerotatus triseriatus (treehole mosquitoes). The primary
vector of CE is a container-breeding mosquito only. Therefore, human activities which
can increase the numbers of containers, such as tires or buckets, can increase the
population of the treehole mosquito. In 2007, the Department lab tested only those
persons negative for WNV and younger than 18 years of age for CE due to limitations on
reagents for testing. A total of 55 cases were reported in the United States from 10
states. The three states reporting the most cases were Tennessee, West Virginia and
Ohio.
SLE also can be identified in persons in Illinois. In 2007, eight cases of SLE were
reported from states. In the United States, there also were three cases of EEE reported,
seven cases of Powassan and no cases of WEE.
Dengue and Chikungunya
Several arboviruses seen in Illinois result from traveling overseas, including
Dengue and Chikungunya. Chikungunya epidemics have occurred in Africa, India, and
southeast Asia. The disease is transmitted by the Aedes mosquito. Chikungunya virus is
a mosquito-borne disease indigenous to tropical Africa and Asia. The primary reservoirs
are primates and rodents. However, the range has spread to India and Italy. The
incubation period is usually three to seven days. Chikungunya virus is an illness
characterized by fever, myalgias, lower back pain and arthralgias accompanied by rash
and conjunctivitis. The arthritis primarily affects smaller joints such as the wrists and
ankles. The polyarthralgias can be very debilitating. It is estimated that from 3 percent to
25 percent of persons with Chikungunya infections are asymptomatic. The diagnosis
should be considered in travelers to endemic areas who have fever and arthritis.
Serologic testing may be negative during the first week of infection. RT-PCR testing may
be more sensitive early in the course of illness. Patients may be viremic for six to seven
days (shortly before and during the febrile period). No autochtonous cases have
occurred yet in the United States. Treatment consists of supportive care, including
analgesics, and anti-inflammatory medications.
Dengue is an arbovirus caused by four serotypes (DEN-1, DEN-2, DEN-3 and
DEN-4). Dengue is the most common arbovirus in tropical and subtropical parts of the
world. United States residents who travel to countries with endemic dengue are at risk
for the disease. The incubation period ranges from three to 14 days. Dengue infection
can range from asymptomatic to mild to more severe disease. A second infection with a
different serotype can result in dengue hemorrhagic fever. Persons traveling to areas
with dengue should wear repellents and protective clothing. Diagnosis is by acute and
convalescent serum samples. Dengue was not nationally notifiable in 2007, but became
notifiable in 2010.
Arboviral encephalitis prevention includes limiting mosquito bites in humans and
reducing mosquito habitat. Mosquito bites can be minimized by using appropriate
repellents, by avoiding the outdoors during peak mosquito feeding times and by repairing
30
screens on windows and doors. The use of repellents provides the best protection
against mosquitoes. Prevention involves personal protective behaviors and mosquito
control activities. People can eliminate breeding areas for mosquitoes such as standing
water in clogged rain gutters.
During the period May 15 through October 31, physicians and laboratories in
Illinois are encouraged to submit cerebrospinal fluid (CSF) from aseptic meningitis and
encephalitis cases to the Department laboratory for further testing. In addition, serum
samples are requested for testing for arboviral antibody from clinically compatible cases.
The CSF can be examined for antibodies to LAC, SLE and EEE viruses upon request.
Case definition
The case definition for a confirmed case of arboviral encephalitis in Illinois is a
clinically compatible illness that is laboratory confirmed at either commercial laboratories
or public health laboratories. The laboratory criteria are a fourfold or greater rise in serum
antibody titer; or isolation of virus from, or demonstration of viral antigen in tissue, blood,
CSF or other body fluid; or specific IgM antibody in CSF. A probable case of arboviral
encephalitis is a clinically compatible illness occurring during the season when arbovirus
transmission is likely to occur and with the following supportive serology: a stable
(twofold or smaller change) elevated antibody titer to an arbovirus, e.g., at least 320 by
hemagglutination inhibition, at least 128 by complement fixation (CF), at least 256 by IF,
at least 160 by neutralization, or a positive serologic result by enzyme immunoassay
(EIA).
Descriptive epidemiology
California encephalitis surveillance
Number of cases – One case of CE was reported in Illinois in 2007.
Individual case description
• A 6-year-old boy from Cook County was diagnosed with CE in 2007. He
was hospitalized for four days with fever, headache, agitation, seizures,
depressed consciousness and diarrhea. Laboratory testing of enzyme
immunoassay and PRNT at CDC was positive. He is believed to have
acquired infection in Cook County.
• Past incidence - The reported cases of CE in Illinois are as follows: 1990 (one),
1991 (15), 1992 (seven), 1993 (two), 1994 (six), 1995 (five), 1996 (13), 1997
(three), 1998 (four), 1999 (three), 2000 (three), 2001 (five), 2002 (eight), 2003
(11), 2004 (eight), 2005 (one) and 2006 (none) (Figure 20).
Chikungunya surveillance
• Number of cases reported in Illinois – Two Chikungunya cases were reported in
Illinois residents.
• Individual case descriptions
o One probable case was male in his fifties and a resident of Cook County
who traveled to India and had onset in July. There was a fourfold rise in his
titer by PRNT and virus was isolated from serum. He was seen at an
emergency department but was not hospitalized.
o A confirmed case was a female in her sixties living in Chicago with travel
to Nigeria. Onset of illness was in December with serum PRNT testing
31
positive at CDC. She had fever, rash, myalgias and arthralgias. She was
seen in an emergency department but was not admitted.
SLE surveillance
• Number of cases reported in Illinois - No cases of SLE were reported in 2007.
Dengue surveillance
• Number of cases reported in Illinois – No cases of Dengue were reported in
2007.
West Nile virus surveillance
Human
•
•
•
•
•
•
•
•
•
•
Number of cases reported in Illinois – There were 101 WNV cases reported; 40
(40 percent) were confirmed and 61 (60 percent) were classified as probable
(Figure 21). The five year median was 215. The incidence in Illinois was 0.8 cases
per 100,000 population. Six asymptomatic blood donors were reported.
Age – Ages ranged from 2 weeks to 87 years of age (mean = 50 years) (Figure
22).
Gender – Sixty-three (62 percent) of the cases were male.
Race/ethnicity – Cases reported the following race, white (88 percent), AfricanAmerican (7 percent) and other (4 percent). Ten percent of cases reported being
Hispanic.
Diagnosis – The Department laboratory performed the MAC ELISA test on all
submitted specimens. Of the reported cases with known site of positive test, 100
positive results occurred as follows: both serum and CSF (20 cases), CSF only
(18) and serum only (62).
Clinical presentation – Cases were classified as: West Nile fever (26),
neuroinvasive disease (64) and other (11) (Figure 23). Of the neuroinvasive
cases, 34 were classified as encephalitis, 23 were classified as meningitis and
seven were classified as flaccid paralysis. Cases exhibited the following
symptoms: fever, 82 (84 percent); stiff neck, 40 (44 percent); rash, 31 (33 percent)
and change in consciousness, 28 (32 percent).
Hospitalization – Sixty-four of 98 (65 percent) cases were hospitalized.
Fatalities – Three cases were fatal. All three fatal cases had neuroinvasive
disease. Fatal cases ranged in age from 69 to 81 years of age (mean = 76 years).
Seasonal distribution – Onset of cases ranged from June 2 (Dupage County)
through December 11 (Hardin County). The highest number of case onsets
occurred in September. Figure 24 shows the number of WNV infections by month.
Table 2 shows the earliest human onset per year from 2002 through 2007.
Geographic distribution – Twenty-nine counties had evidence of WNV activity in
humans (Figure 25). The largest number of cases per county (33, 33 percent)
occurred in Cook County (0.61 per 100,000 population). Case numbers and
incidence rates in selected other counties were DuPage (10, 1.1 per 100,000),
Kane (13, 3.21 per 100,000) and Lake (five, 0.77 per 100,000).
32
•
•
Reporting – Of the 99 cases with the reporting source listed, the most frequent
reporters were hospital personnel (38 percent), the Department laboratory (33
percent) and private or hospital laboratories (24 percent).
Historical – The number of cases reported in Illinois were 2002 (884), 2003 (53),
2004 (60), 2005 (252) and 2006 (215).
Bird testing
The number of counties submitting birds for WNV testing: 2004 (69), 2005 (62),
2006 (89) and 2007 (85). Twenty-three counties in 2007 reported positive birds (27
percent of counties submitting birds for testing). Bird types that could be submitted for
WNV testing was expanded to include robins, grackles, starlings, house sparrows,
blackbirds, cardinals and mourning doves as well as crows and blue jays. The total
submitted for each species: crow (58, 43 percent positive), blue jay (34, 20 percent),
house sparrow (20, 5 percent), cardinal (13, 0 percent), house finch (15, 13 percent),
starling (26, 0 percent), grackle (70, 3 percent), robin (99, 0 percent). One hundred fortythree other types of birds were submitted with 1 percent testing positive. Birds were
tested using immunohistochemistry testing (IHC).
The first positive bird of the season was collected on July 25 from Cook County
and the last positive bird of the season was collected on October 10 from Montgomery
County.
Mosquito pool testing
In 2007, 62 counties submitting mosquito pools for testing (39 percent) had pools
that tested positive. The first positive mosquito sample was collected on January 17,
2007, from Cook County. The last positive mosquito pool was identified in October 22,
2007, in Dupage County. In 2007, 1,553 of 38,271 mosquito pools (4 percent) pools
tested positive.
Horses reported with WNV
Five horses were reported with WNV in 2007. Date of report ranged from August
29 (McHenry County) to October 14 (Logan County). The five horses were stabled in
Logan, McHenry, Monroe, Tazewell and Whiteside counties.
Other species
No other animals were positive for WNV in 2007.
Summary
Because encephalitis cases are more commonly reported in the summer months
in Illinois, the Department asks physicians to increase testing to establish the etiology
and to report individuals with acute encephalitis from May 15 to October 31 each year.
Positive dead birds were collected in Illinois between July 25 and October 10.
There were no cases of CE and no cases of SLE reported in 2007. During 2007,
human WNV cases were reported from 29 of the 102 counties in Illinois. In 2007, the
majority of the cases were in the Chicago metropolitan area.
33
Suggested readings
Gubler, D.J. The continuing spread of West Nile virus in the Western hemisphere.
Clin Inf Dis 2007;45:1039-46.
Staples, J.E., et. al. Chikungunya fever: An epidemiological review of a reemerging infectious disease. Clin Inf Dis 2009;49:942-48.
Number of cases
Figure 20. California Encephalitis Cases in Illinois, 2002-2007
15
10
11
9
8
5
1
1
0
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 21. West Nile virus Cases in Illinois, 2002-2007
1000
800
600
400
200
0
884
252
2002
215
60
53
2003
2004
2005
2006
101
2007
Year
Number of cases
Figure 22 . Reported WNV Cases in Illinois by Age, 2007
40
30
20
10
0
0-14 yrs
15-29 yrs
30-44 yrs
Age category
34
45-59 yrs
>59 years
Figure 23. Clinical Syndrome for WNV Cases in Illinois, 2007
Other
11%
WNV fever
26%
WNV fever
WNV meningitis
23%
WNV encephalitis
WNV meningitis
Other
WNV encephalitis
40%
Table 2. Earliest Onset of a Human Case, 2002-2007
Year
2002
2003
2004
2005
2006
2007
Earliest human onset
July 2
July 15
June 11
June 29
May 27
June 2
Number of cases
Figure 24. Epidemic Curve for Human WNV Cases in Illinois, 2007
60
40
20
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Week of onset
35
Aug
S ep
Oct
Nov
Dec
Figure 25. Incidence Rate by County for Human WNV Cases, 2007
36
Haemophilus influenzae (Invasive Disease)
Background
Haemophilus influenzae is an obligate pathogen of the human respiratory tract
and can cause invasive disease such as meningitis, septic arthritis, pneumonia,
epiglottitis and bacteremia. H. influenzae forms part of the normal flora of the human
throat and is divided into six serotypes (a through f). The polysaccharide capsule is a
known virulence factor and is the antigen used in serotyping. The organism is
transmitted by droplets and discharges from the nose and throat. The incubation period
is probably short, from two to four days. Children younger than 5 years of age should be
vaccinated against H. influenzae. Prior to the introduction of vaccine against serotype b,
most cases were due to serotype b. Reductions in asymptomatic carriage reduces Hib
disease. Full vaccination with primary Hib vaccine by 7 months of age is critical to protect
children from disease.
In December 2007, recalls and cessation of production of two Hib-containing
vaccine products left a shortage. CDC recommended that providers defer the 12-15
month booster dose. In 2007, 401 cases were reported in those younger than 5 years of
age in the United States. Five percent of all cases in children younger than 5 years of
age were attributable to type B.
The Healthy People 2010 objectives are to decrease the incidence of invasive H.
influenzae in children younger than 5 years of age to 0.
Case definition
The case definition for a confirmed case of invasive H. influenzae in Illinois is a
clinically compatible illness with isolation of the organism from a normally sterile site. A
probable case is a clinically compatible illness and detection of H. influenzae type b
antigen in CSF.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 - 124 (five-year median = 120). All
cases were confirmed. From 2002 to 2007, the number of cases reported per year
ranged from 109 to 135 (Figure 26).
• Age – Seventy-five percent of the cases were older than 49 years of age (mean =
59 years of age) (Figure 27). Ages ranged from newborn to 99 years of age. One
type b case was in a person younger than 5 years of age.
• Gender - Sixty percent of cases were in females.
• Race/ethnicity - Sixteen percent were African Americans, 77 percent were white,
and 7 percent were other races; 12 percent were Hispanic.
• Seasonal distribution – H. influenzae occurs throughout the year, with an increase
in the winter months (Figure 28).
• Presentation – The case presentations for 94 cases were bacteremia (46
percent), pneumonia (40 percent), meningitis (7 percent), epiglottitis (2 percent),
septic arthritis (2 percent), abscess (1 percent) and peritonitis (1 percent).
• Outcome – Ninety-six percent of 114 reported cases for which information was
available were hospitalized. Six of 58 (10 percent) cases for which information
was available died due to H. influenzae. Ages of the fatal cases ranged from 28 to
85.
37
•
•
•
•
•
Diagnosis - All cases were culture confirmed. H. influenzae was isolated from
blood (113 cases), CSF (six cases), synovial fluid (two), peritoneal fluid (one),
amniotic fluid (one) and sterile site, unknown location (one).
Serotype results – Typing results were available for 104 of 124 (84 percent) of
cases. For the 104 cases with typing available, the following serotypes were
identified: f (11 cases), b (seven cases), e (six cases), d (two cases) and a (one
cases. Seventy-one of the cases were non-typable.
Geographic location – Forty percent of the cases resided in Cook County.
Epidemiology – Seven cases resided in residential facilities, such as assisted
living or long-term care.
Reporting – Reporters included hospital personnel (non-laboratory) (84), the
Department laboratory (22), private or hospital laboratory staff (17) and other
reporters (one).
Summary
The number of H. influenzae cases in 2007 was similar to the five-year median. Of
the isolates that were typed, 7 percent were type b. Cases occur throughout the year.
One type b case occurred in a children younger than 5 years of age for whom the
vaccine is indicated. The 7 percent of isolates serotyped as type b was lower than the 11
percent seen in 2006. Sixty-eight percent of cases in 2007 were untypable. Seventy-five
percent of all cases occurred in people older than 49 years of age.
Suggested readings
CDC. 2008. Active Bacterial Core surveillance report, Emerging infections
Program Network, Haemophilus influenzae, 2007. Available on the Internet:
http:www.cdc.gov/ncidod/dbmd/abcs/survreports/hib07.pdf.
Rainbow, J., et. al. Invasive Haemophilus influenza type B disease in five young
children-Minnesota, 2008. MMWR 2009;58(3): 58-61.
38
Number of cases
Figure 26. H. influenzae Cases in Illinois, 2002-2007
150
135
120
124
109
124
120
100
50
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 27. H. influenzae Cases by Age in Illinois, 2007
80
60
40
20
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-59 yr
>59 yr
Year
Number of cases
Figure 28. H. influenzae Cases in Illinois by Month, 2007
20
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
39
Aug
Sep
Oct
Nov
Dec
Listeriosis
Background
Listeriosis is a rare cause of human illness but it can lead to severe disease, with
a case fatality rate of 20 percent. Listeriosis is caused by infection with Listeria
monocytogenes, which is common in the environment. It is a foodborne illness that can
cause sepsis in immunocompromised persons and meningoencephalitis and febrile
gastroenteritis in immunocompetent persons. Febrile gastroenteritis is considered to be
uncommon. A study in Canada identified only 17 cases of L. monocytogenes in 8,000
stool specimens submitted for diagnosis of a diarrheal illness.
Patients receiving antineoplastic therapy are more susceptible to listeriosis.
Bloodstream infection, sepsis and meningitis are typical clinical presentations. Listeriosis
has the highest case fatality rate of any foodborne illness. Risk factors for mortality in
Los Angeles for non-perinatal listeriosis were underlying disease such as
nonhematologic malignancy, alcoholism, kidney disease and other factors such as
steroid medication or age older than 69 years. Pregnant women whose gastrointestinal
tracts become colonized with the bacteria after they eat contaminated foods can transmit
the organism to the fetus or can contaminate the baby’s skin or respiratory tract during
childbirth.
The median incubation period is three weeks, which makes identifying a suspect
food vehicle difficult. L. monocytogenes is found frequently in nature and can be cultured
from foods and the environment, which makes typing of isolates from patients and
suspected food items important. The majority of isolates from cases are 1/2 a, 1/2 b or
4b. Pulse field gel electrophoresis can be used to further discriminate between isolates.
Contaminated food vehicles often identified in outbreaks of listeriosis in the United States
include unpasteurized dairy products. However, other vehicles have been identified. One
listeriosis outbreak in Massachusetts in 2007 was linked to consumption of pasteurized
milk. The same strain of Listeria was identified in milk and in four patients.
L. monocytogenes can resist salt, heat, nitrite and acidity better than many other
organisms. It also can survive and multiply at cold temperatures. Refrigerators at 40° F
or below are best for reducing the potential for listeriosis.
Of the 10 diseases/syndromes under active FoodNet surveillance (those caused
by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria
monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica), listeriosis
comprised 122 of 16,801 (0.73 percent) of the reported infections in 2007. Incidence
rates ranged from 0.12 to 0.37 per 100,000 at the 10 sites with an overall incidence of
cases of 0.27 per 100,000 population.
In 2007, 808 cases of listeriosis were reported to CDC from 52 states and
territories.
Case definition
Illinois uses the CDC case definition for Listeria cases: a clinically compatible
history (stillbirth, listeriosis of the newborn, meningitis, bacteremia or localized infection)
and isolation of L. monocytogenes from a normally sterile site. In the setting of
miscarriage or stillbirth, isolation of L. monocytogenes from placental or fetal tissue is
adequate as laboratory confirmation. A maternal-child pair will only be counted as one
maternal case.
40
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – There were 34 total cases reported
(five were described as cases of meningitis). All cases were confirmed. The fiveyear median is 24 (Figure 29). The 2007 incidence for all reported listeriosis was
0.27 per 100,000 population.
• Age - Cases ranged in age from infant to 90 years of age; 73 percent of cases
were older than 59 years of age.
• Seasonal distribution – Cases occurred from January to December.
• Gender – Fifty percent of cases were female.
• Race/ethnicity - Eighty-one percent of the cases were white, 12 percent were
African American and 6 percent were other races. Eighteen percent reported
Hispanic ethnicity.
• Geographic location – Forty-four percent of the cases were reported from Cook
County. Fourteen counties reported cases.
• Diagnosis - The site of Listeria isolation was identified as follows: blood (29) and
one each for cerebrospinal fluid, heart tissue, placenta, synovial fluid and brain.
CDC typed 22 isolates. They were typed as 4b (eight), 1 / 2 b (five), 1 /2 a (four)
and 4c (two), 3a (one) and untypable (two). PFGE was done on 21 isolates. All 21
patterns were unique to each other in 2007.
• Underlying conditions – Twenty-one of 22 (95 percent) cases with information
available on immunosuppressive conditions reported an immunosuppressive
condition. These included pregnancy, cancer, diabetes mellitus, renal
disease/dialysis or steroid therapy.
• Clinical – Thirty of 32 cases with information available were hospitalized. Types of
infections were septicemia (11), meningitis (four), pneumonia (two), abscess (two)
and one each for endocarditis and septic arthritis. One case had a stillborn baby.
Another pregnant case had a healthy infant. One fatal case was reported and that
person was 61 years of age.
• Epidemiology – Three cases resided in residential facilities. All three were in longterm care facilities.
• Reporting – Seventy-five percent of cases were reported by hospital personnel
other than laboratory personnel.
• There were no outbreaks of reported listeriosis in Illinois in 2007.
Summary
In 2007, Illinois recorded 34 listeriosis cases; 73 percent of the cases were older
than 59 years of age. The incidence rate (0.27) was the same as described by CDC’s
FoodNet sites in 2007 (0.27 per 100,000). The most common serotypes were 4b and 1 /
2 b. All PFGE patterns were unique.
Suggested Readings
CDC. Foodborne Active Disease Surveillance Network. Surveillance Report 2007.
Available at http://www.cdc.gov/foodnet/annual/2007/2007_annual_report_508.pdf
Guevara, R.E., et. al. Risk factors for mortality among patients with non perinatal
listeriosis in Los Angeles County, 1992-2004. CID 2009;48:1507-1515.
41
Number of cases
Figure 29. Listeriosis Cases in Illinois, 2002-2007
40
30
32
23
24
31
34
24
20
10
0
2002
2003
2004
2005
Year
42
2006
2007
Invasive Neisseria meningitidis
Background
N. meningitidis is an important cause of bacterial meningitis and septicemia in the
world. The bacteria that causes meningococcal disease, N. meningitidis, is carried in the
pharynx by about 5 percent to 10 percent of the population. The organism is transmitted
by direct contact with respiratory droplets from the nose and throat of an infected person.
Most patients acquire infection from an asymptomatic carrier during face-to-face contact
including coughing, sneezing and kissing and the sharing of drinks, foods or cigarettes.
The incubation period ranges from two to 10 days and is usually three to four days.
Meningococcal disease is an acute bacterial disease that may be characterized by fever,
headache, stiff neck, delirium and, often, a rash and vomiting. It presents as meningitis
in 80 percent to 85 percent of cases. Septicemia also can result from infection with N.
meningitidis. The overall case fatality rate is between 10 percent and 14 percent.
Carriage of the meningococcus organism is transient and the level of carriage does not
predict the course of an outbreak. Less than 1 percent of exposed persons who become
infected develop invasive disease. Rates are highest in infants with a second peak in
those aged 18 years. Among those aged 11 to 19 years, 75 percent of cases are caused
by A, C, Y, W-135. The majority of cases in infants are group B.
Antimicrobial chemoprophylaxis is used for close contacts of cases. Only close
contacts should be given chemoprophylaxis due to concerns about antimicrobial
resistance. Vaccination can be used as an adjunct measure to protect against A, C, Y
and W135 serogroups. A meningococcal vaccine that protects against these serogroups
was licensed in the United States in 1982. It is given routinely to military recruits and to
certain travelers. A second vaccine using conjugate technology was approved in early
2005 for protection against the same four serotypes among persons aged 2 to 55 years.
A tetravalent (A,C,Y,W-135) conjugate meningococcal vaccine, Menactra® was licensed
for persons aged two to 55 years. In 2007, ACIP recommended routine use of MCV4 to
include children aged 11 to 12 years and adolescents aged 13 to 18 years. Specific
vaccination campaigns are used in highly selected situations.
In October 2007, FDA approved the quadrivalent meningococcal conjugate
vaccine (MCV4 Menactra®, Sanofi Pasteur) for use in children aged 2 to10 years, in
addition to its use in the 11-to-55 year age group. The use of their vaccine was
recommended for children at increased risk for meningococcal disease (those with
terminal complement deficiencies or those with anatomic or functional asplenia) and
travelers to endemic areas. The recommendations also state that MCV4 is preferable to
MPSV4 (Menamume, Sanofi Pasteur). Also, the recommendation to routinely vaccinate
persons aged 11 to 18 remained in effect.
A national immunization survey in 2007 of adolescents aged 13 to 17 identified
that meningococcal vaccine had been received by 32 percent of adolescents nationally
as compared to only 12 percent in 2006.
In 2007, 2,154 cases were reported in the United States. The Healthy People
2010 objective is to reduce invasive N. meningitidis to one case per 100,000 population.
Case definition
The case definition for a confirmed case of meningococcal disease is a clinically
compatible case with N. meningitidis isolated from a normally sterile site or from skin
scrapings of purpuric lesions. The case definition for a probable case is a compatible
43
illness with PCR positive from a normally sterile site or evidence of N. meningitidis from
latex agglutination of CSF or positive immunohistochemistry on formalin fixed tissue. A
suspect case has clinical purpura fulminans in absence of positive blood culture or
clinically compatible case with gram negative diplococci from a normally sterile site.
Suspect cases are not counted as official cases in the case count for Illinois.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 - 61 (incidence of 0.49 per 100,000)
(five-year median = 46) (Figure 30). Fifty-eight cases were confirmed and three
were probable. At least three cases were reported to be in college students.
• Age - The age distribution of reported meningococcal disease is shown in Figure
31. Mean age of cases was 40 (range: one week to 86 years of age)
• Gender – Forty-four percent of cases with gender information were female.
• Race/ethnicity – Thirty-three percent of cases were African American, 60 percent
were white and 7 percent were other; 6 percent were Hispanic.
• Seasonal distribution - Meningococcal disease occurred throughout 2007 with
increases in March and June (Figure 32).
• Geographic location – Fifty-nine percent of reported cases were from Cook
County. Other counties with more than one case (two each) were Champaign,
Kane, Lake, Sangamon and Vermilion.
• Presentation – For 40 cases with case reports, the presentation of illness was
bacteremia (47 percent), meningitis (40 percent) and pneumonia (12 percent).
• Outcome – Fifty-four of 60 (90 percent) of individuals with information available
were hospitalized. The case fatality rate was 11 percent for patients where the
outcome of infection was known. Ages of the seven fatal cases were from three to
63 years of age.
• Diagnosis - The organism was isolated from blood only (49 cases), CSF only
(seven), blood and CSF (one). One case classified as confirmed only had CSF
latex agglutination positive and should have been counted as probable. For three
probable cases, diagnostic testing included identification of gram negative
diplococcic in brain tissue (one), CSF and blood PCR (one) and antigen testing of
CSF (one). Serogrouping was performed on isolates from 53 (87 percent) of
cases. In cases where typing was done, the serogroups identified were Y (36
percent), C (30 percent), B (25 percent), W-135 (6 percent) and nontypable (4
percent) (Figure 33).
• Contacts given prophylaxis – For 11 cases, the number of close contacts given
prophylaxis was reported. The number ranged from one to 23 contacts (median =
five).
• Reporting – Fifty-one cases were reported by hospital personnel excluding
laboratory personnel.
• Clusters – None reported. No clusters requiring a vaccination campaign occurred
in 2007.
Summary
The number of N. meningitidis cases reported in Illinois in 2007 (61) was higher
than the five-year median (46 cases). Eighty-seven percent of isolates were serogrouped
in Illinois, which is less than the 93 percent serogrouped in the United States from 1998
44
through 2007. Serogroup Y was the most common serogroup reported. The incidence of
0.49 per 100,000 in Illinois is similar to that reported from a CDC estimate incidence for
the United States of 0.53 per 100,000 from 1998 through 2007. Eleven percent of cases
were fatal, which is similar to that reported by CDC for the United States from 1998
through 2007.
Suggested readings
ACIP. Recommendations from the Advisory Committee on Immunization
Practices (ACIP) for use of quadrivalent meningococcal conjugate vaccine (MCV4) in
children aged 2-10 years at increased risk for invasive meningococcal disease. MMWR
2007;56(48):1265-6.
CDC. 2008. Active bacterial core surveillance report. Emerging infections program
network, Neisseria meningitidis, 2007. Available on the intranet: http:www.cdc.gov /
ncidod/dbmd/abcs/survreports/mening07.pdf
Cohn, A.C. et al. Changes in Neisseria meningitidis disease epidemiology in the
United States, 1998-2007: Implications for prevention of meningococcal disease. Clin Inf
Dis 2010;50:184-91.
Jain, N. et. al. Vaccination coverage among adolescents aged 13-17 years –
United States, 2007. MMWR 2008; 57(40):1100-1103.
Number of cases
Figure 30. Meningococcal Disease in Illinois, 2002-2007
73
80
60
61
57
46
36
40
34
20
0
2002
2003
2004
2005
Year
45
2006
2007
Number of cases
Figure 31. N. meningitidis Cases by Age in Illinois, 2007
20
15
10
5
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-59 yr
>59 yr
Year
Number of cases
Figure 32. N. meningitidis Cases in Illinois by Month, 2007
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year
Number of cases
Figure 33. N. meningitidis Cases in Illinois by Serogroup, 1993-2007
80
B
60
C
40
Y
20
Other
0
1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
Year
46
Invasive Group B Streptococcus
Background
Group B streptococcus and E. coli cause most cases of sepsis in infants. Around
10 percent to 35 percent of pregnant women may be colonized with group B
streptococcus at the time of labor placing them at risk for transmitting the disease to their
infants.
Group B streptococcus infections are due to Streptococcus agalactiae and cause
disease and death in newborns and morbidity in peripartum women and nonpregnant
adults with chronic medical conditions. Early-onset disease of neonates (less than seven
days) may consist of sepsis, respiratory distress, apnea, shock, pneumonia and
meningitis. The infection is acquired during delivery or in utero. Early-onset disease is
caused by maternal group B streptococcus carriage. Risk factors for early-onset group B
streptococcal sepsis (that occur within 72 hours of life) include fever in the mother during
labor, preterm delivery, membrane rupture greater than 18 hours before delivery and a
mother with a previous infant with group B streptococcus. Infants acquire infection
through aspiration of contaminated amniotic fluid or during passage through the birth
canal. Late-onset disease (seven days to several months) is characterized by sepsis and
meningitis and is acquired by person-to-person contact. Only about 50 percent of lateonset disease cases have been shown to be of maternal origin.
Persons at higher risk in the CDC’s Active Bacterial Core Surveillance were older
persons, African Americans and adults with diabetes. Invasive group B streptococcus in
adults mainly causes bacteremia without focus or pneumonia. Most isolates are from
blood. The incidence of adult group B streptococcal disease has increased to seven
cases per 100,000 in 2007.
Case definition
A confirmed case of invasive group B streptococcus disease is defined as
isolation of GBS from a normally sterile site (e.g., blood or cerebrospinal fluid). A
probable case is defined as a person who is latex agglutination positive for group B
streptococcus from a sterile site. Only cases younger than 3 months of age were
required to be reported in Illinois in 2007.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – There were 92 cases reported; 75
cases were younger than 3 months of age. Seventeen cases were in older age
groups.
• Age – Seventy-five of 92 (81 percent) of cases were younger than 3 months of
age. Only cases younger than 3 years of age were reportable in 2007.
• Gender – Thirty-eight of 75 (51 percent) of all cases younger than 3 months were
female. Fifty-three percent of those older than 3 months were female.
• Race/ethnicity – Fifty-six percent of all cases younger than 3 months were white
and 36 percent were African American; 21 percent were Hispanic.
• Seasonal variation – There were small increases in cases in May, September and
October in cases younger than 3 months of age.
• Diagnosis – Eighty-four of 92 cases (all ages) were confirmed by a positive
culture. The organism was isolated from blood (75 cases), CSF (six cases), blood
47
•
•
and CSF (one case) and other or unknown sites (two cases). The laboratory
confirmation for other cases included latex agglutination in four cases. In two
cases the type of laboratory testing was unknown at the time of this report.
Case outcome – Seventy-two of 74 cases (97 percent) younger than 3 months of
age were hospitalized; two cases were known to be fatal. For those older than 3
months of age, 14 of 14 cases were hospitalized and one fatality occurred among
this age group.
Reporter – Seventy-three of the 92 cases (79 percent) were reported by hospital
personnel excluding hospital laboratory personnel and 13 were reported by
hospital laboratory personnel
Summary
Cases of invasive group B streptococcal disease in newborns can be prevented if
the appropriate guidelines are followed by health care providers. Ninety-two cases of
group B streptococcus disease were reported in Illinois, the majority in those younger
than 3 months of age. Although only group B streptococcal disease in those younger
than 3 months of age is reportable, voluntary reporting of invasive group B streptococcus
disease in persons older than 3 months of age occurs.
48
Cryptosporidiosis
Background
Cryptosporidiosis is primarily a gastrointestinal disease that affects humans and
45 other species. Disease results from infection with Cryptosporidium species oocysts.
There are 12 species recognized. Two species, C. hominis (previously known as C.
parvum genotype 1) and C. parvum (previously known as C. parvum, genotype 2) are
the most important human pathogens. The organism is shed in the feces in the form of
an oocyst, which has a hard shell to protect it from the environment. Oocysts are
immediately infective upon excretion by an infected host and can be shed for up to two
weeks or longer in immunocompetent humans. Illness can be caused by ingestion of
only 10 oocysts. Infection is spread through person-to-person transmission, from direct
contact with animals and by swimming in contaminated water. Approximately 1 percent
to 3 percent of the general population may be excreting oocysts. The incubation period is
an average of seven days (range is one to 12 days). Predominant symptoms include
profuse and watery diarrhea accompanied by abdominal cramping. Infection in
immunocompetent people lasts one to two weeks. Persons at risk for more severe
infection include young children, pregnant women or persons with weakened immune
systems. A new treatment for cryptosporidium, nitazoxanide was made available.
Oocysts of cryptosporidia can be found in many types of water including untreated
surface water, filtered swimming pool water and even from chlorine-treated or filtered
drinking water. The minimum level of detectable oocysts that pose a public health threat
in domestic water supplies is not known. Outbreaks have occurred due to person-toperson and waterborne spread. Cryptosporidium is the leading cause of reported
outbreaks of gastroenteritis linked to treated swimming venues.
Of the 10 diseases under active surveillance in FoodNet sites (illnesses caused
by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria
monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica),
Cryptosporidium comprised 7 percent of the reported infections. The incidence rate
overall was 2.7 per 100,000 for Cryptosporidium and incidence ranged from 0.6 to 6.1 at
the ten FoodNet sites in 2007.
In 2007, 11,657 confirmed cryptosporidiosis cases were reported to CDC through
NETSS. The number of cases was highest in those one to nine years of age. A tenfold
increase occurred from summer to fall when there is increase usage of recreational
water. There was a large increase in 2007 as compared to prior years due to several
large outbreaks.
Important features of cryptosporidiosis include: 1) waterborne outbreaks are
typical, 2) oocysts are resistant to commonly used disinfectants 3) transmission can
occur by direct fecal-oral contact, 4) as few as 10 to 100 oocysts can cause infection, 5)
oocysts are infectious upon excretion and 6) asymptomatic infections occur. There was
an outbreak of cryptosporidiosis in a splash park in Idaho in 2007. Splash parks have
multiple interactive water features that spray visitors with little to no supervision.
Prevention of outbreaks includes advising ill persons to wash hands with soap
and water after using the toilet and before eating or preparing food, to avoid swimming in
recreational water during illness and for at least two weeks after diarrhea stops and to
avoid fecal exposure during sexual activity. Environmental control measures, such as
hyperchlorination, may be needed when outbreaks in recreational water facilities are
discovered. For splash parks, ultraviolet or ozone treatment systems can increase
safety.
49
Case definition
A confirmed symptomatic case of cryptosporidiosis in Illinois is laboratory
confirmed (demonstration of Cryptosporidium oocysts in stool by microscopic
examination, or demonstration of Cryptosporidium in intestinal fluid or small bowel biopsy
specimens, or demonstration of Cryptosporidium oocyte or sporozite by a specific
immunodiagnostic test such as ELISA or by PCR techniques or demonstration of
reproductive stages in tissue preparations) and is associated with one of the following
symptoms: diarrhea, abdominal cramps, loss of appetite, low-grade fever, nausea or
vomiting. A confirmed asymptomatic case is a laboratory confirmed case associated with
none of the symptoms described above.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – 205 (five-year median = 160; see
Figure 34). Four cases were probable; the rest were confirmed. The incidence
rate was 1.6 per 100,000. CDC only counts 201 confirmed cases for Illinois for
2007.
• Age - Mean age for all 2007 cases was 35 years. Age distribution of cases is
shown in Figure 35.
• Gender – Forty-four percent were male.
• Race/ethnicity – Seventy-seven percent were white, 16 percent were African
American, and 4 percent were other races; 8 percent were Hispanic.
• Seasonal variation - Cases peaked from July through October (Figure 36).
• Clinical – Two cases were reported to be asymptomatic. Symptoms included
diarrhea (97 percent), fever (40 percent) and vomiting (48 percent); 30 percent
were hospitalized, no cases were fatal.
• Geographic location – The three counties with the highest incidence of
cryptosporidiosis were: JoDaviess (54 per 100,000), Carroll (24 per 100,000) and
Mercer (18 per 100,000).
• Reporting – The most common reporters were laboratory staff (94) and infection
control professionals (92).
• Risk factors –
o Contact with animals – Contact with animals was reported by 177 cases,
including eight who had contact with cattle. One individual worked on a
dairy farm and drank unpasteurized milk and some of the cattle had
diarrhea. Another child helped his grandfather on his cattle farm.
o Travel - Seventeen persons reported travel outside the United States
including travel to Mexico (four) and Italy (three). Thirty–eight cases
traveled out-of-state but within the United States including 11 who traveled
to Iowa and 10 who traveled to Wisconsin.
o Swimming – Fifty-two of 182 (28 percent) of the cases reported swimming
in chlorinated water. Twenty-seven of 183 (15 percent) reported swimming
in non-chlorinated water.
o Well water exposure – Seventeen of 188 cases (9 percent) reported
drinking private well water.
o Day care contact – Thirteen of 184 cases (7 percent) reported contact with
a day care facility.
o Residential facility – Twenty of 181 cases (11 percent) had contact with a
50
•
residential facility.
Outbreaks: In 2007, two recreational water outbreaks were reported. These
outbreaks are discussed in further detail in the foodborne and waterborne disease
outbreak section.
Summary
The number of reported cases of cryptosporidiosis in 2007 was lower than the
number reported in 2006. Two outbreaks were reported in 2007. Most cases in 2007
occurred in the late summer and early fall. The incidence of reported cryptosporidiosis in
Illinois (1.6 per 100,000) was lower than the incidence reported in FoodNet sites (2.7).
Suggested Readings
Centers for Disease Control and Prevention. FoodNet 2007 Surveillance Report.
Atlanta: U.S. Department of Health and Human Services, 2009.
Yoder, J.S., et. al. Cryptosporidiosis surveillance – United States, 2006-2008.
MMWR 2010; 59(SS-6). 1-25.
Number of cases
Figure 34. Cryptosporidiosis Cases in Illinois, 2002-2007
257
300
205
200
161
121
160
102
100
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 35. Age Distribution of Cryptosporidiosis Cases in Illinois, 2007
50
40
30
20
10
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
Year
51
30-39 yr
40-49 yr
50-59 yr
>59 yr
Number of cases
Figure 36. Cryptosporidiosis Cases in Illinois by Month, 2007
60
40
Outbreak
20
Non-outbreak
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Month of Onset
52
Sep
Oct
Nov
Dec
Cyclosporiasis
Background
Cyclosporiasis is caused by a protozoal organism, Cyclospora cayatensis.
Clinical illness consists of watery diarrhea and abdominal cramping. Diarrhea is usually
self-limiting but may be prolonged. The median incubation period is seven days.
Transmission to persons is usually through drinking or swimming in contaminated water.
Several international outbreaks have involved consumption of raspberries from
Guatemala. Basil and lettuce also have been implicated in transmission.
In 2007, 93 confirmed cyclosporiasis cases were reported to CDC through
NETSS. Florida reported the most cases in 2007. Of the 10 diseases under active
surveillance in FoodNet sites (illnesses caused by Campylobacter, Cryptosporidium,
Cyclospora, E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella, Shigella, Vibrio
and Yersinia enterocolitica), (13 of 18,039) Cyclospora comprised 0.07 percent of the
reported infections in 2007. Data from 2007 showed the incidence rate was 0.03 per
100,000 for Cyclospora and ranged from 0.0 to 0.10 at the ten FoodNet sites.
Case definition
Laboratory confirmation is the finding of C. cayatensis oocysts in stool by
microscopic examination or in intestinal fluid or small bowel biopsy specimens; or
demonstration of sporulation or PCR positive in stool, duodenal/jejunal aspirates or small
bowel biopsy specimens. CDC has two case classifications:
Confirmed, symptomatic - laboratory confirmed with clinically compatible illness.
Confirmed, asymptomatic - laboratory confirmed with no symptoms.
Descriptive epidemiology
Number of cases reported in Illinois in 2007 – Three confirmed cases were reported. All
were symptomatic.
• Age – The median age for cases was 36 years.
• Gender – Sixty-seven percent were female.
• Race/ethnicity – Two were white and one did not report race; Hispanic status was
unknown.
• Seasonal variation – Case onsets were reported in June (two) and February
(one).
• Geographic location – All three cases resided in Cook County.
• Travel – Two persons traveled overseas, one to Peru and one to Guatamala.
Summary
No outbreaks of cyclosporiasis were reported in Illinois in 2007.
Suggested readings
Centers for Disease Control and Prevention. FoodNet 2007 Surveillance Report.
Atlanta: U.S. Department of Health and Human Services, 2009.
53
Ehrlichiosis and Anaplasmosis
Background
Ehrlichia are bacteria that infect a wide variety of animals and are transmitted by
tick bites. One case of HGA was transmitted by blood transfusion in Minnesota in 2007
Because HGA is a rare disease and there is not a cost effective test method for the
disease, blood donor’s are not screened for HGA. Four Ehrlichia pathogens have been
identified in the United States: E. chaffeensis (causing human monocytic ehrlichiosis
(HME)), Anaplasma phagocytophilum (formerly Ehrlichia phagocytophila) causing human
granulocytic anaplasmosis (HGA), E. canis and E. ewingii. Only one person with E. canis
has been reported and the person was not clinically ill. E. chaffeensis and E. canis
mainly invade the monocyte, and the disease caused by these organisms is termed
HME. A. phagocytophilum and E. ewingii invade mainly the granulocytes and the
disease is referred to as granulocytic ehrlichiosis. Both HGA and HME are zoonotic
diseases requiring an arthropod vector and a mammalian reservoir. A specific history of
a tick bite can be elicited in about 68 percent of ehrlichiosis cases.
E. chaffeensis, the primary cause of HME, is transmitted to humans primarily by
the lone star tick, A. americanum. The white-tailed deer is a major host for this tick and
acts as a natural reservoir for E. chaffeensis. Cases of HME are most commonly
reported from Missouri, Oklahoma, Tennessee, Arkansas and Maryland.
The blacklegged tick (Ixodes scapularis) is the vector for A. phagocytophilum
which causes HGA in New England, the North Central United States and Europe.
E. ewingii can be carried by Ambylomma americanum. Cases of HGA caused by
E. ewingii have been reported primarily in immunocompromised patients from Missouri,
Oklahoma and Tennessee. Infection also may occur in dogs.
Both HME and HGA result in similar symptoms: fever, headache and myalgia.
Cases also may have low platelets, low white blood cells and increased liver enzymes.
Rash occurs in approximately one third of HME patients and is rare in patients with HGA
or E. ewingii. In 25 percent of HME cases, respiratory tract involvement occurs, and in
20 percent of cases central nervous system disease occurs. More than 40 percent of
HME cases require hospitalization, and severe complications can include
meningoencephalitis, acute respiratory distress syndrome, toxic shock like syndrome,
renal failure, coagulopathy and multiorgan failure. Serious outcomes can occur with HGA
in persons with impaired immune systems. These Ehrlichia organisms can form clusters
of organisms called morulae, in the white blood cells. There is strong cross reactivigy to
ehrlichia types when serology is used for diagnosis.
The case fatality rate has been reported as 5 percent in HME and 10 percent in
HGA. All symptomatic cases of HGA should be treated. Fever should be reduced within
48 hours of the initiation of antimicrobial therapy.
In 2007, 834 HGA, 828 HME and 337 other or unknown types of ehrlichiosis
cases were reported to CDC. There was an increase in HME and HGA in the United
States over previous years. Illinois was eighth in the nation for the number of HME
cases.
Case definitions
HME
A clinically compatible illness with demonstration of a four-fold change in antibody
titer to E. chaffeensis antigen by IFA in paired serum or positive PCR and confirmation of
E. chaffeensis DNA, or identification of morulae in leukocytes and a positive IFA titer to
54
E. chaffeensis antigen, or immunostaining of E. chaffeensis antigen in a biopsy or
autopsy specimen or positive culture for E. chaffeensis in a clinical specimen.
HGA
A clinically compatible illness with demonstration of a four-fold rise in antibody titer
to A. phagocytophilum antigen by IFA in paired serum or positive PCR and confirmation
of A. phagocytophilum DNA, or identification of morulae in leukocytes and a positive IFA
titer to A. phagocytophilum antigen, or immunostaining of A. phagocytophilum antigen in
a biopsy or autopsy specimen or positive culture for A. phagocytophilum in a clinical
specimen.
Ehrlichiosis, human, other or unspecified agent
A clinically compatible illness with demonstration of a four-fold change in antibody
titer to more than one Ehrlichia/Anaplasma species by IFA in paired serum samples, in
which a dominant reactivity cannot be established, or identification of
Ehrlichia/Anaplasma species other than E. chaffeensis or A. phagocytophilum by PCR,
immunostaining or culture.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 - 50; Thirty-seven were HME, six
were HGA and seven were ehrlichiosis/anaplasmosis, type unknown.
HME cases
• Seven HME cases were confirmed and 30 were probable.
• Age – HME cases ranged in age from 6 to 77 years of age (mean = 48 years).
• Gender – Twenty-four cases were male and 13 were female.
• Race/ethnicity – Thirty-one HME cases were white, one reported “other” race and
five did not report race; One reported Hispanic ethnicity.
• Residence of cases – Cases resided in 25 Illinois counties.
• Exposure Sites – Thirty-one HME cases reported in-state tick exposures.
Counties in which exposures took place included Franklin (three), Jefferson
(three), Perry (three), Williamson (three), Adams (two), Jackson (two) and one
each in Calhoun, Cass, Dupage, Fulton, Hancock, Johnson, Logan, Marion,
McHenry, Monroe, Moultrie, Pike, Sangamon, Union and Winnebago. Fifty-five
percent of exposures were reported from the Marion region (southern Illinois).
Two cases reported tick exposure out-of-state (one in Missouri and one in
Wisconsin). Four did not report an exposure location.
• Seasonal variation – Onsets of HME cases were from April to October (Figure 37
shows onsets by month for all ehrlichiosis/anaplasmosis cases).
• Diagnostic testing – The cases of HME were diagnosed by a single serologic titer
(30 cases), PCR (four) and four-fold rise in titer (three).
• Clinical syndrome – Symptoms reported by HME cases were fever (31 of 35),
rash (9 of 32), headache (26 of 34) and myalgia (26 of 31).
• Outcomes – Sixty-one percent of cases were hospitalized. There was one fatality
reported.
• Reporting – All but 5 cases were reported by laboratories.
• Past incidence – The number of reported cases of ehrlichiosis in Illinois in past
years: 2004 (four) and 2005 (five) and 2006 (25).
55
HGA cases
• Number of cases – Six cases of HGA were reported and all were probable cases.
• Age – HGA cases ranged in age from 20 to 73 years of age (mean = 54 years).
• Gender - Five cases were male and one was female.
• Race/ethnicity – Four HGA cases were white and two did not report race; none
were reported to be Hispanic.
• Residence of cases – HGA cases resided in Adams, Cook, Kane, Mason,
McHenry and Saline counties.
• Exposure Sites – Three HGA cases were exposed in-state; one in Saline County,
one in Adams and one in multiple counties (Cass, Mason and Fulton). Three
cases reported tick exposure in Wisconsin.
• Seasonal variation – Onsets of HGA cases were from May to October (Figure 37
includes all ehrlichiosis/anaplasmosis cases).
• Diagnostic testing – All cases were diagnosed by serologic testing.
• Clinical syndrome – Symptoms reported by HGA cases were fever (six of six),
rash (two of six), headache (five of six) and myalgia (five of six).
• Outcomes – Fifty percent of cases were hospitalized and no fatalities were
reported.
• Reporting – All cases were reported by laboratories.
• Past incidence - Reported cases of ehrlichiosis in Illinois in past years have been
infrequent : 2004 (one) and 2005 (two) and 2006 (six).
Unknown ehrlichiosis type
• Number of cases – Seven cases were reported in 2007; four were confirmed and
three were probable.
• Age – The unknown ehrlichiosis type cases ranged in age from 28 to 82 years of
age (mean = 55 years).
• Gender - Five cases were male and two were female.
• Race/ethnicity – Six was white and one did not report race; no cases reported
being Hispanic.
• Residence of cases – Cases resided in Jefferson (three) and one each in Adams,
Calhoun, Jackson and Sangamon counties.
• Exposure Sites – Five cases were exposed in-state; three in Jefferson County,
one in Adams and one in Calhoun County. One case reported out-of-state tick
exposure in Missouri. One case had an unknown exposure site.
• Seasonal variation – Onsets occurred between May and August (Figure 37
includes all cases of ehrlichiosis/anaplasmosis).
• Diagnostic testing – Four cases were diagnosed by PCR and three by serologic
testing.
• Outcomes – Seventy-one percent of cases were hospitalized.There were no
fatalities reported.
• Reporting – Four were reported by infection control personnel and three by
laboratories.
• Past incidence - Reported cases of ehrlichiosis in Illinois in past years have been
infrequent : 2004 (seven) and 2005 (one) and 2006 (one).
56
Summary
Thirty-seven ehrlichiosis cases were reported in Illinois in 2007. Sites of tick
exposure for HME cases were primarily in southern Illinois. Most onsets were from May
through July.
Suggested readings
Kemperman, M., et. al. Anaplasma phagocytophilum transmitted through blood
transfusion – Minnesota, 2007. MMWR 2008;57(42):1145-48.
Number of cases
Figure 37. Onsets of All Ehrlichiosis Cases Reported in Illinois by
Month, 2007
20
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Onset
57
Aug
Sep
Oct
Nov
Dec
Shiga-toxin Producing E. coli, Enterotoxigenic E. coli, enteropathogenic E. coli)
Background
Strains of Escherichia coli that cause diarrhea are classified into pathotypes.
Shiga toxin producing E. coli (STEC) may cause bloody diarrhea and hemolytic uremic
syndrome because they produce Shiga toxins. Enteropathogenic E. coli (EPEC) lack
Shiga toxins and cause nonspecific diarrhea in infants in less-developed countries.
Enterotoxigenic E. coli outbreaks are rarely reported in the United States.
E. coli O157:H7 is one type of STEC and was first recognized as a cause of
human illness and associated with ground beef in 1982. E. coli O157:H7 causes
primarily a diarrheal illness. The infectious dose is thought to be low due to evidence of
person-to-person transmission and recreational water exposure transmission. The
incubation period is from three to eight days with an average of three to four days.
Occasionally, longer incubation periods have been reported. Infection with E. coli
O157:H7 produces symptoms that range from mild to bloody diarrhea and that may
progress to hemolytic uremic syndrome (HUS) or thrombotic thrombocytopenic purpura
(TTP); 3 percent to 5 percent of HUS cases are fatal. The term HUS is used to describe
acute renal failure accompanied by non-immune hemolytic anemia and
thrombocytopenia. It occurs most frequently in children younger than five years of age
after infection by an agent producing shiga toxin. The illness can involve the central
nervous system (CNS), pancreas, heart and other organs. HUS can be caused by
Shigella dysenteriae type 1 and STEC. The most common cause of HUS in the United
States is E. coli O157:H7.
STEC can be transmitted within households from children who are infected. In a
study in Wales, 20 of 98 (22 percent) households during an outbreak of E. coli O157:H7
had secondary cases within the household. Primary cases were mainly children.
Household transmission mainly occurred from children to their younger siblings. Young
age of the primary case (less than five years) was a risk factor for secondary cases in
the household. Separating the primary case from siblings may present secondary
infections in households. In a study of STEC in Minnesota, E. coli O157:H7 were more
likely than non-O157 cases to involve bloody diarrhea, hospitalization and HUS.
E. coli O157:H7 is transmitted through consumption of contaminated food or
beverage, person-to-person contact or swimming in contaminated recreational water. In
a study in Washington state, risk factors for E. coli O157:H7 infections were exposure to
aquatic recreation, using private wells and residential septic systems and domestic travel
within the United States. In a study in Australia, case patients with E. coli O157:H7 were
more likely to report eating hamburgers and eating at restaurants as compared to
controls. Risk factors for non-O157 STEC included occupational exposure to animals,
consumption of sliced processed chicken meat, camping, eating at a catered event and
eating sliced corn beef.
During 2007, 4,847 STEC cases were reported from 49 states. Three serogroups
(O26, O103 and O111) accounted for 67 percent of the non-O157 isolates.
Of the 10 diseases under active surveillance in the FoodNet sites (illnesses
caused by Campylobacter, Cryptosporidium, Cyclospora, E. coli O157:H7, HUS, Listeria
monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica), E. coli
O157:H7 was responsible for 546 of 18,039 (3 percent) of the reported infections in 2007
data. STEC non-O157 were responsible for 272 of 18,039 (1.5 percent) of the reported
infections. The incidence rate for E. coli O157:H7 was 1.2 per 100,000 and ranged from
0.4 to 3.2 per 100,000 at the ten FoodNet sites. The incidence rate for STEC non-O157
58
was 0.6. On STEC non-O157, the following were the most common O antigens
identified: O103 (21 percent), O26 (20 percent), O121 (17 percent) and O111 (15
percent).
CDC recommends that all bloody diarrheal stools be routinely cultured for E. coli
O157:H7. Rapid tests also are available to directly detect shiga toxin in stool specimens.
Specimens testing positive should be cultured to identify which organism (E. coli or
Shigella) produced the shiga toxin. Broth culture media or specimens in which shiga
toxin has been detected should be cultured for E. coli or submitted to the state public
health laboratory for E. coli isolation.
Pulsed-field gel electrophoresis (PFGE) is done routinely in Illinois on E. coli
O157:H7 isolates that are submitted to the state laboratory. Epidemiologic investigation
into a cluster of cases should occur after finding a match by two enzyme PFGE. Single
enzyme analysis is insufficient to determine whether isolates and cases are truly related.
Enterotoxigenic E. coli is believed to be a common cause of traveler’s diarrhea.
United States residents who travel overseas may return to the United States with ETEC.
Enterotoxigenic E. coli is not identified by routine stool culture methods.
Prevention measures for enteric E. coli infections include cooking food thoroughly,
prompt refrigeration of foods and separation of cooked and raw foods. Antibiotics are
contraindicated for treatment of E. coli O157:H7 infections; this treatment leads to
release of toxin as bacteria die and increased risk for development of hemolytic uremic
syndrome (HUS).
Food safety practices that can decrease risk of E. coli O157:H7 from ground beef
include thawing frozen ground beef in the refrigerator, not at room temperature, and
cooking to a temperature of 160° F. Kitchen items in contact with raw ground beef
should be washed thoroughly before reusing.
Case definition
The case definition for a confirmed case of E. coli O157:H7 used in Illinois is a
clinically compatible illness with isolation of E. coli O157:H7 from a stool specimen or E.
coli O157 organisms that are laboratory confirmed as producing shiga toxin. E. coli
isolated in stool from a person with clinically compatible illness that produce shiga toxin
but are not identified as O157 also is reportable as shiga toxin producing E. coli, nonO157. A confirmed case of ETEC is a clinically compatible illness with laboratory
confirmation of enterotoxigenic E. coli from stool. A confirmed case of enteropathogenic
E. coli is a clinically compatible illness with laboratory confirmation of enteropathogenic
E. coli from stool. A probable case of ETEC or enteropathogenic E. coli, or STEC is a
clinically compatible case which is epidemiologically linked to cases but has not been
laboratory confirmed.
Descriptive epidemiology
Shiga-toxin producing E. coli, including E. coli O157:H7
• Number of cases reported in Illinois in 2007 – 131 (five-year median = 124) (see
Figure 38). An additional four cases of STEC, shiga toxin positive but not cultured
or serotyped were not counted in CDC numbers. The incidence for the 131 STEC
cases in Illinois was 1.05 cases per 100,000 population. Of these 131 cases, 112
were identified as E. coli O157:H7, 13 were identified as E. coli O157, H antigen
unknown. Six were identified as STEC, non-O157. Nine cases were probable and
the rest were confirmed.
59
•
•
•
•
•
•
•
•
•
Age - Cases ranged in age from 8 months to 77 years of age (mean = 24 years of
age) (Figure 39).
Gender – Fifty percent were female.
Race/ethnicity – Ninety-two percent were white, 6 percent were African American,
and 2 percent were other races; 5 percent of cases were Hispanic.
Seasonal variation - The largest number of cases occurred in the months from
June to October (77 percent of cases) (Figure 40).
Geographic location – The county with the most cases was Cook (27 cases),
followed by Effingham (12 cases). Ten of the Effingham cases were linked to one
outbreak in the county.
Clinical syndrome – Of the 125 cases with symptom information, 100 percent
reported diarrhea, 83 percent reported bloody diarrhea, 51 percent reported
vomiting and 30 percent reported fever; five cases (8 percent of patients for whom
information was available) had HUS and no cases had thrombotic
thrombocytopenic purpura (TTP). Four cases reportedly were put on dialysis.
Seventy-nine of 125 cases (63 percent) were hospitalized. No cases were
reported to be fatal.
Reporter – The most common reporters included infection control professionals
(57 percent) and laboratories (37 percent).
Sensitive occupations - There were two cases involving health care workers, two
involving workers at food service facilities and one involving a worker at a
daycare.
Outbreaks – Two foodborne outbreaks were reported in 2007. (see detailed
description in the “Food and Waterborne Outbreaks” section).
Risk factors
• Eight of 119 (7 percent) of the cases reported contact with a day care. There were
four of 113 (3 percent) of cases reporting contact with a residential facility.
• Three cases attended pre-school.
• Travel –
o Twenty-two of 120 cases (18 percent) reported traveling to another state.
o Missouri and Indiana were the most common destinations (six each).
o Two of 116 cases (2 percent) reported traveling to another country during
their incubation period. One traveled to the Ukraine and one to the
Dominican Republic.
• Animal contact
o Sixty-one of 109 cases (56 percent) reported contact with animals. Five
cases had contact with cattle. Two of the persons reporting cattle contact
had recently attended cattle sales in different locations.
• Well water exposure - Fifteen of 121 (12 percent) reported drinking well water.
• Recreational water exposure
o Sixteen cases of 117 (14 percent) reported swimming in non-chlorinated
water.
o Nineteen of 114 cases (17 percent) reported swimming in chlorinated
water.
• Ground beef consumption –
o Sixty-six of 102 cases (65 percent) reported consuming ground beef.
o Eleven of these cases reported consuming the ground beef undercooked.
60
ETEC
•
Number of cases reported in Illinois in 2007 - None.
Other types of reportable enteric E. coli
There were no other types of E. coli infections reported in 2007.
Summary
The incidence of infection with E. coli O157:H7 in 2007 was 0.9 cases per
100,000 population, which is lower than what was found in CDC’s FoodNet sites (1.2 per
100,000).
Most cases (77 percent) of shiga toxin producing E. coli occurred in the months of
June through October. Bloody diarrhea was reported by 83 percent of case individuals; 8
percent of patients reportedly had HUS diagnosed by a physician. Sixty-three percent of
cases were hospitalized. Sixty-five percent of cases reported consuming ground beef.
Suggested readings
Ahn, C.K., et. al. Isolation of patients acutely infected with Escherichia coli
O157:H7: Low-tech, highly effective prevention of hemolytic uremic syndrome. CID
2008;46:1197-99.
Centers for Disease Control and Prevention. FoodNet 2007 Surveillance Report.
Atlanta: U.S. Department of Health and Human Services, 2009.
Denno, D.M., et. al. Tri-county comprehensive assessment of risk factors for
sporadic reportable bacterial enteric infection in children. JID 2009;199:467-476.
Hedican, E.B., et. al. Characteristics of O157 versus non-O157 shiga toxinproducing Escherichia coli infections in Minnesota, 2000-2006. CID 2009; 49: 558-364.
McPherson, M., et. al. Serogroup-specific risk factors for shiga toxin-producing
Escherichia coli infections in Australia. CID 2009; 49: 249-56.
Werber, D., et. al. Preventing household transmission of shiga toxin-producing
Escherichia coli O157 infection: Promptly separating siblings might be the key. CID
2008;46:1189-96.
Number of cases
Figure 38 Shiga-toxin producing E. coli Cases in Illinois, 2002-2007
250
200
150
100
50
0
E. coli O157:H7
197
124
102
122
96
40
2002
2003
2004
2005
112
8
19
2006
2007
Year
61
STEC, not further specified
Number of cases
Figure 39. Age Distribution of shiga toxin producing E.coli Cases in
Illinois, 2007
40
30
20
10
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
>59 yr
Year
Number of cases
Figure 40. Shiga toxin producing E. coli cases in Illinois by Month, 2007
30
20
10
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
62
Aug
Sep
Oct
Nov
Dec
Foodborne and Waterborne Outbreaks
Background
The surveillance on food-related disease outbreaks (foodborne outbreaks) is
significant in that food can act as a vehicle for transmission of pathogens or their
byproducts. Although many foodborne illnesses result in a few days of diarrhea, with
additional symptoms such as fever, vomiting or muscle aches, others can have serious
health effects such as hemolytic uremic syndrome, reactive arthritis, sepsis or Guillain
Barré syndrome.
Foodborne illness can be caused by microorganisms and their toxins, marine
organisms and their toxins, fungi and chemical contaminants. There are three
categories of organisms to consider in discussing the causes of foodborne illness:
viruses, bacteria and parasites. For some viruses, such as hepatitis A or Noroviruses,
humans are the only reservoir. Prevention of foodborne illness depends heavily on food
handlers and proper food handling practices. Rotaviruses can occasionally cause
foodborne outbreaks. Shellfish have been associated with hepatitis A virus, calicivirus
and Vibrio spp. outbreaks. The use of gloves for food handlers is often recommended to
decrease transmission of enteric pathogens. A study of glove use did not verify that
glove wearers had less coliform bacteria on the food as compared to food handlers who
did not wear gloves. It has been observed that food handlers wear the same pair of
gloves for extended periods of time. Proper hygiene, such as keeping the environment
clean, avoiding cross contamination, and proper hand washing can help prevent a large
number of food and waterborne outbreaks. CDC estimates that in the 1990s
approximately 12 percent of foodborne outbreaks were linked to produce items.
Bacteria comprise the largest category of foodborne agents. These include E.
coli O157:H7, Salmonella and Listeria monocytogenes. Parasites like Trichinella in pork,
Anasakis in raw fish or Cyclospora in raspberries also can cause foodborne illness.
Some enteric pathogens, such as Campylobacter, Giardia and Shigella, rarely cause
foodborne outbreaks.
One common cause of waterborne outbreaks in water parks is cryptosporidiosis.
High flow sand filtration and chlorination disinfection may not be enough to protect
swimmers. Prevention of outbreaks can include signs asking patrons to wash young
children’s bottoms before entering the water, diaper changing only in designated areas,
discouraging of drinking any water and not entering water with diarrhea.
CDC’s Foodborne Disease Active Surveillance Network (FoodNet) is a system to
collect information from seven states and selected counties in three states in the United
States. The network provides stable and accurate national estimates of foodborne
disease occurrences in the country. According to the 2007 FoodNet Surveillance
Report, there were a total of 18,039 laboratory-confirmed cases of infection in their
surveillance system. The incidence of laboratory-confirmed causes was estimated as
follows: Salmonella (14.9 per 100,000), Campylobacter (12.8 per 100,000), Shigella (6
per 100,000), Cryptosporidium (2.7 per 100,000), shiga-toxin producing E. coli (STEC)
O157 (1.2 per 100,000), Yersinia (0.4 per 100,000), Vibrio (0.2 per 100,000), Listeria
63
(0.3 per 100,000), STEC non-O157 (0.6 per 100,000), and Cyclospora (0.03 per
100,000).
In 2007, 1,097 foodborne outbreaks involving 21,244 cases and 18 deaths, were
reported to CDC. For confirmed outbreaks, viruses caused 40 percent of outbreaks and
bacteria caused 52 percent. Chemical agents and parasites caused 1 percent each.
Norovirus was the most common cause, followed by Salmonella. Illinois’s ranking for
the number of confirmed outbreaks reported was bacterial (seventh highest number),
chemical (sixth highest) and viral (third highest). A food vehicle was identified in 43
percent of outbreaks. Poultry, beef and leafy vegetables were the most common food
commodities implicated.
Case definition
A foodborne outbreak is an incident in which two or more persons (usually
residing in separate households) experience the onset of a similar, acute illness (usually
gastrointestinal) following ingestion of common food or drink. With multi-state outbreaks,
there may be one Illinois resident affected and multiple cases from other states. CDC
has established case definitions for confirmed outbreaks and these are listed under the
specific organisms in this outbreak section.
For foodborne outbreaks, the number ill reflects those who meet a clinical case
definition. For outbreaks where the etiologic agent was suspected and not confirmed,
and the clinical syndrome matched the suspect etiologic agent but no laboratory
confirmation was obtained, the suspect cause is ascribed to this etiologic agent.
IDPH receives reports of potential foodborne outbreaks from many sources.
Outbreak investigations, which are conducted by local health departments, may not
result in a confirmed foodborne outbreak designation and will not be counted in the
state totals. There are a number of reasons for this: lack of information, classification as
person-to-person transmission or because the symptoms and incubation period do not
clearly indicate a known foodborne pathogen.
Descriptive epidemiology
The number of possible foodborne or waterborne outbreaks reported to the
Department by local health departments (LHDs) was 91 during 2007. The total for the
year was 79 foodborne outbreaks that met the definition of an outbreak and were
submitted to the Centers for Disease Control and Prevention (CDC). Two recreational
waterborne outbreaks were reported to CDC. Of the 81 foodborne and waterborne
outbreaks, the etiology was confirmed in 34 foodborne and two waterborne outbreaks,
suspected in 28 outbreaks and unknown in 17 outbreaks. Two of the 81 outbreaks were
due to recreational water exposure. (Note: Drinking water outbreaks were not counted
under recreational water outbreaks).
In the year 2007, a total of 2,525 people were reported to have become ill as the
result of the 79 foodborne outbreaks and 10 as a result of the two recreational water
outbreaks.
The mean number of ill persons was 32 per foodborne outbreak and five for
waterborne outbreaks; the median number of cases ill was 10 per foodborne outbreak
and five for waterborne outbreaks; the number of ill persons per outbreak ranged from
64
one to 526 for foodborne and waterborne outbreaks combined. The outbreaks with one
Illinois resident affected were due to multi-state outbreaks. There were 105 persons
hospitalized as a result of the foodborne outbreaks and one hospitalized due to
waterborne outbreaks. There were no fatalities reported due to foodborne or waterborne
illness during the year 2007. Foodborne outbreaks reported during 2007 were from the
following counties: Cook (38), Kane (nine) and DuPage (four); three each for the
counties of McHenry and Rock Island; two each for the counties of Mclean, Tazewell
and Winnebago; and one each for the counties of Effingham, JoDaviess, Madison,
McDonough, Peoria, Stephenson, Vermilion, Warren, Wayne, Will, Williamson and
Woodford; and there were four multi-county or multi-state foodborne outbreaks
recorded. The waterborne outbreaks were reported from the counties of Jo Daviess and
Winnebago.
The 79 reported foodborne outbreaks occurred in the following months: January,
seven (9 percent); February, five (6 percent); March, four (5 percent); April, seven (9
percent); May, seven (9 percent); June, seven (9 percent); July, 12 (15 percent);
August, seven (9 percent); September, five (6 percent); October, seven (9 percent);
November, five (6 percent); and December, six (7 percent) (Figure 41). Both
recreational water outbreaks were in August. In the 79 foodborne and recreational water
outbreaks reported, the etiologic agent was determined to be due to bacterial agents
(infection or intoxication), either suspect or confirmed, in 27 (34 percent) (Tables 3 and
4). The bacterial pathogens were as follows: Salmonella spp. (12 outbreaks), shiga
toxin producing E. coli (four), Clostridium perfringens toxin (four), Bacillus cereus/ S.
aureus toxin (one), B. cereus/C perfringens toxin (two), S. aureus (two) and
Campylobacter (two). The etiologic agent in 33 (42 percent) of the 79 foodborne
outbreaks was suspected or confirmed to be caused by viruses. One was confirmed to
be hepatitis A. Thirty-two of the 33 were attributed to norovirus infection. Nine (28
percent) of these were confirmed. The remaining 23 (70 percent) of norovirus outbreaks
were classed as suspect norovirus outbreaks, largely based on symptoms, incubation
and duration in the people who were affected. One foodborne outbreak was due to
tetrodotoxin and one due to lead. Both of the recreational water outbreaks were caused
by parasitic agents.
Although thorough investigations were conducted, there was inconclusive
evidence to classify either suspect or confirm etiologic agents in 17 (21 percent) of the
foodborne or recreational water outbreaks and they were thus classified as etiology
unknown.
Food handlers were laboratory tested in 15 of the foodborne outbreaks (19
percent). In 13 (87 percent) of the outbreaks food handlers were found to be positive for
the etiologic agent implicated in the outbreak. Food handlers tested positive for
norovirus in six outbreaks and Salmonella in seven outbreaks. In one outbreak involving
E. coli O157:H7 and one outbreak due to unknown cause, food handlers were negative.
Environmental samples were taken in two foodborne outbreaks and neither of the
waterborne outbreaks.
Through either epidemiology, supportive information or food testing, 25 food or
water items were implicated in outbreaks. In seven outbreaks, meat products were
implicated (poultry for three outbreaks, ground beef for two outbreaks and pork for two
65
outbreaks). The poultry products involved were roasted turkey, shredded chicken and
turkey. The pork products implicated were roasted pork and pork barbeque. Vegetables
were implicated in one outbreak (lettuce). Fish was implicated in one outbreak (puffer
fish) and dairy products in one outbreak (unpasteurized cheese). Complex foods were
implicated in 11 outbreaks. Complex food items implicated were chili, dill dip and
raspberry dressing, pasta, pancit palabok, pighead meat and salsa, enchiladas, beef
burritos, pot pie, taco salad, beef stew and chocolate strawberries and deli sandwiches.
Other food items involved included Veggie Booty snack food, hummus and Sindoor.
The food causing illness in 54 foodborne outbreaks (70 percent) was unknown.
Food was tested for pathogens in 23 (30 percent) of the outbreaks. Positive
foods were found in 12 (52 percent) of the 23 outbreaks where samples were tested.
The responsible pathogens found were Salmonella (four), C. perfringens (three), S.
aureus (two), fecal coliforms (one), tetrodotoxin (one) and lead (one). In one of the 12
outbreaks the food tested positive in states other than Illinois.
The site of food preparation in 78 foodborne or drinking water outbreaks with
available information were: restaurant, 44 (56 percent); private home, seven (9 percent);
caterer, three (4 percent); banquet facility, three (4 percent); grocery, three (4 percent),
commercial product, four (5 percent) and one each for one percent each for school,
hotel and sailing club. Eleven (14 percent) had food preparation done at multiple sites.
The two recreational waterborne outbreaks were from entering pools.
The site where the food was consumed was: restaurant, 30 (38 percent); private
home, 16 (20 percent); work, 11 (14 percent); banquet facility, four (5 percent); fair,
three (4 percent); park, two (2 percent) and one each in hotel, sailing club, tavern,
church, picnic, grocery and school (1 percent each). In six outbreaks (8 percent) food
was consumed in multiple areas.
In 29 (35 percent) of the foodborne and drinking water outbreaks, contributing
factors were known. Food handlers were identified as a contributing factor in 68 percent
of the outbreaks. Other contributing factors included improper holding temperatures (21
percent), contaminated raw products (14 percent) and preparing food ahead of time (14
percent). Other contributing factors included unlicensed product, cross contamination,
commercial product not cooked properly, contaminated product, insufficient reheating
and contaminated storage site.
A line listing of outbreaks is provided in Table 5.
Figure 41. Number of Foodborne Outbreaks by Month of
First Onset, Illinois, 2007
15
Number of 10
outbreaks
reported 5
0
Jan Feb Mar Apr May Jun
Jul Aug Sep Oct Nov Dec
Month
66
Summary
In 2007, Illinois recorded 79 foodborne and two waterborne outbreaks compared
to a five-year median of 69. The most common site of food preparation in the reported
outbreaks was restaurants. Issues with food handlers were the most commonly reported
contributing factor to outbreaks. For confirmed outbreaks, viruses caused a lower
percent (29 percent) of Illinois outbreaks as compared to 40 percent on the national
level. For confirmed outbreaks, bacteria caused a higher percent (65 percent) of Illinois
outbreaks as compared to national data (52 percent). Nationally, food items were
implicated in 43 percent of outbreaks as compared to 32 percent in Illinois. In 2007, the
month of July had an increased number of outbreaks.
Suggested readings
Boone, A., et. al. Surveillance for foodborne disease outbreaks – United States,
2007. MMWR 2010; 59(31): 973-979.
Centers for Disease Control and Prevention. FoodNet 2007 Surveillance Report.
Atlanta: U.S. Department of Health and Human Services, 2009.
Jue, R., et. al. Outbreak of cryptosporidiosis associated with a splash park,
Idaho, 2007. MMWR 2009;615-618.
Table 3. Foodborne Outbreaks, Cases and Deaths by Etiology in Illinois, 2007
Outbreaks
Cases
#
Etiology
Count
%
Count
Bacterial
B. cereus/S. aureus **
1
1
3
B. cereus/C. perfringens**
2
2
24
Campylobacter
2
2
21
Clostridium perfringens
4
5
56
Shiga-toxin producing
Escherichia coli (O157:H7)
4
5
15
Salmonella
12
15
974
Staphylococcus aureus
2
2
87
Total Bacterial*
27
34
1,180
Chemicals/Fish Toxin
Tetrodotoxin
1
1
2
Total Chemical/Fish Toxin
1
1
2
Heavy metal
Lead
1
1
3
Total Heavy Metal
1
1
3
Viral
Hepatitis A
1
1
2
40
Norovirus
32
1,192
Total Viral
33
42
1,194
Unknown etiology
17
21
146
Total 2007
79
-
2,525
#
%
Deaths
Count
0.1
0.9
0.8
2
0
0
0
0
---
0.6
38
3
47
0
0
0
0
---------
0.08
0.08
0
0
-----
0.1
0.1
0
0
-----
0.08
47
47
6
0
0
0
0
---
-
Confirmed and suspected etiologies
** Suspected intoxication
* Some outbreaks are suspected to be due to bacterial intoxication with more than one suspected pathogen.
67
%
-----
---
Table 4. Foodborne Outbreak Pathogens by Testing Status in Illinois, 2007
Confirmed
Suspected
Etiology
Count
%
Count
Bacterial
B. cereus/S. aureus **
0
--1
B. cereus/C. perfringens**
0
--2
Campylobacter
1
3
1
Clostridium perfringens
4
12
0
Shiga-toxin producing
Escherichia coli (O157:H7)
3
9
1
Salmonella
12
35
0
Staphylococcus aureus
2
6
0
Total Bacterial
22
65
5
Chemicals/Fish toxin
Tetrodotoxin
1
3
0
Total Chemical/Fish toxin
1
3
0
Heavy metal
Lead
1
3
0
Total Heavy Metal
1
3
0
Viral
Norovirus
9
26
23
Hepatitis A
1
3
0
Total Viral
10
29
23
Total 2007
34
--28
.
68
%
3
7
3
--3
----18
--------82
--82
---
Unknown
Count
%
Specific Types of Foodborne Outbreaks
Bacillus cereus
B. cereus causes foodborne illness through intoxication. There are two types of
illness caused by B. cereus, depending on the enterotoxin elaborated by the organism.
In one type, the incubation period is from one to six hours and symptoms last 12 hours
or less. Almost all individuals experience vomiting and about one-third experience
diarrhea. The illness is caused by a preformed enterotoxin. Rice has been associated
with this type of B. cereus in past outbreaks. In the other type, the incubation period
ranges from eight to 16 hours and symptoms last less than 24 hours. Diarrhea is a
prominent feature but vomiting is absent. Foods associated with previous outbreaks
include custards, cereals, and meat or vegetable dishes. The organism multiplies
rapidly at room temperature and the spores can survive boiling.
Case definition
Laboratory confirmation for B. cereus includes isolation of greater than 105
organisms per gram in properly handled food or isolation of the organism from two or
more ill people and not from controls.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 - None confirmed. There was
one outbreak that may have been caused by either B. cereus or S. aureus
intoxication as suggested by the clinical presentation and two outbreaks in which
the clinical picture suggested either B. cereus or C. perfringens intoxication, both
were not confirmed.
• Bacillus cereus had been identified as the cause of one foodborne outbreak in
2002, five outbreaks in 2003, and two in 2006; there were no outbreaks caused
by B. cereus in 2004, 2005 or 2006.
Campylobacter species
Campylobacter infection usually presents as bloody diarrhea, abdominal pain,
nausea, vomiting and fever within two to five days of exposure. However, there are
asymptomatic cases of campylobacteriosis. Cases are often associated with improper
handling of raw poultry or eating raw or undercooked poultry.
Case definition
Campylobacteriosis is diagnosed through isolation of the organism from any
clinical specimen. Two or more cases with a common epidemiologic link constitute an
outbreak.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 - One outbreak of
Campylobacter was confirmed and one was suspected. A total of 21 persons
became ill and none were hospitalized.
• Individual Descriptions of Confirmed Outbreaks
o An outbreak of Campylobacter jejuni occurred in September in Wayne
County. Eighteen persons became ill after a rehearsal dinner meal. Food
69
•
was prepared in several places for the event including a private home, a
church and a caterer. Unlicensed individuals were used for some of the
food preparation. No foods were tested. Three persons were laboratory
confirmed for Campylobacter. No persons were hospitalized. No specific
food was linked to illness by epidemiologic analysis.
There were only two outbreaks caused by Campylobacter in the previous 5 year
period and these outbreaks occurred in 2005 and 2006.
Campylobacter
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
July
September
Counties of outbreaks
Cook
Wayne
Confirmed
1
18
18
0
0
Suspected*
1
3
3
0
0
0
1
1
0
0
1
1
0
Clostridium perfringens
Another foodborne intoxication is caused by C. perfringens enterotoxin. Diarrhea
is common but symptoms of vomiting and fever are usually absent. The incubation
period is eight to 16 hours (usually 12 hours). The illness lasts one day or less. Almost
all outbreaks are associated with the inadequate heating or reheating of meats or
gravies, which allows the organism to multiply. The enterotoxin is heat-resistant.
Case definition
There are three ways to establish laboratory confirmation of a C. perfringens
outbreak: 1) isolation of greater than 105 organisms per gram of food that has been
properly handled for testing, 2) demonstration of enterotoxin in the stool of two or more
ills, or 3) isolation of greater than 106 organisms per gram in the stool of two or more ill
persons.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 – Four outbreaks were
confirmed; two outbreaks were suspected to be due to either C. perfringens or B.
cereus without laboratory confirmation. For the four confirmed outbreaks, foods
that tested positive in three outbreaks were roasted pork, turkey and chili. In one
outbreak, shredded chicken was epidemiologically linked to illness. In four of
these outbreaks improper holding temperature was believed to be contributing
factor. The site at which food was prepared for the four confirmed outbreaks was
restaurant (two outbreaks), caterer (one) and private home (one).
• Individual Descriptions of Confirmed Outbreaks
o An outbreak of confirmed C. perfringens Type A occurred in Kane County
70
•
in January. Twenty-three of 40 persons developed symptoms after a
median of nine hours following a party at a home. One person had illness
resulting in hospitalization, colectomy and hepatorenal failure. Tissue
samples from her colon tested positive for C. perfringens by PCR testing.
No fatalities were reported. Testing of chili from the meal revealed
1,500,000 organisms per gram of C. perfringens Type A. Contributing
factors to this outbreak were preparing foods ahead and improper hot
holding temperatures and improper temperature and time for reheating.
o An outbreak of C. perfringens occurred in July in Kane County in
individuals eating a lunch brought in from a restaurant. A total of seven
persons reported illness. Five individuals were positive for C. perfringens.
Shredded chicken was linked by epidemiologic analysis. Foods were kept
at incorrect holding temperatures.
o Foods were catered to an airline work place. Fourteen persons became ill
following the meal. Turkey was served that was reported to have a foul
smell and service of the food was stopped. Turkey tested positive for C.
perfringens at 250,000 per gram. Food was prepared in advance and may
have been held at improper temperatures.
o Twelve persons became ill after a party held in a private home in
December in Chicago. Roast pork was purchased at a restaurant and
brought home. Roast pork tested positive for C. perfringens at 2,100,000
per gram. Two ill persons tested negative for C. perfringens. Restaurant
inspection revealed improper holding temperatures for foods. No one was
hospitalized.
C. perfringens caused four foodborne outbreaks in 2002, three in 2003, one in
2004, and two in 2006 and there were none in 2005 and 2006.
Confirmed
4
56
14
1
0
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
January
July
November
December
Counties of outbreaks
Cook
Kane
Food testing
1
1
1
1
2
2
Chili, positive
Turkey, positive
Roasted pork, positive
71
Shiga toxin producing E. coli (E. coli O157:H7 and others)
Foodborne outbreaks of E. coli O157:H7 have been linked to undercooked
ground beef, apple cider, sprouts and lettuce. Other types of E. coli also can be
pathogenic in humans and cause outbreaks.
A total of 4,847 shiga toxin producing E. coli cases reported to CDC in 2007.
Ground beef is the most common vehicle in foodborne outbreaks. Produce-associated
outbreaks are also common. Person-to-person outbreaks occur most commonly in day
care centers.
Case definition
Laboratory confirmation of an outbreak occurs when E. coli O157:H7 or other
Shiga toxin-producing E. coli is isolated from stool of two or more ill persons or from the
implicated food or water.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 – Four STEC outbreaks were
reported and all were due to E. coli O157:H7. Three confirmed and one suspect
E. coli O157:H7 outbreak were reported. Outbreaks occurred in DuPage,
Effingham, St Clair and Warren. A total of 15 people became ill and 12 were
hospitalized. There were no fatal cases. A specific food item was implicated in
two of the four outbreaks. The food item was ground beef and it was implicated
as a result of investigations in other states. For the three confirmed outbreaks
two different Xba1 PFGE patterns were identified. The contributory causes for
two outbreaks was contamination of raw product (ground beef). For two
outbreaks the contributing factors were unknown.
• Individual Descriptions for Confirmed Outbreaks
o A confirmed E. coli O157:H7 outbreak occurred in September in
Effingham County. Ten cases were reported from patrons of a restaurant.
One person developed HUS and seven persons were hospitalized. The
CDC PFGE pattern was EXHX01.0047/EXHA26.0015. All food handlers
tested negative and no specific food could be linked to illness. All
environmental specimens taken of surfaces at the restaurant tested
negative. All food samples tested from the restaurant tested negative.
Onsets of illness were September 13 to September 17.
o One Illinois resident from St. Clair County with onset in April was linked to
a multi-state outbreak of E. coli O157:H7 (EXHX01.0047) associated with
ground beef. The case was hospitalized.
o One Illinois resident from Dupage County with onset in April was linked to
a multi-state outbreak of E. coli O157:H7 (EXHX01.0200) associated with
ground beef. The case was hospitalized.
• There were two STEC outbreaks in each of the following years: 2002, 2003,
2004 and 2006 each; one outbreak was reported in 2005.
72
E. coli O157:H7
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
April
July
September
Counties of outbreaks
Dupage, multi-state
Effingham
St. Clair, multi-state
Warren
Food tested
Food handlers tested
Environmental specimen tested
Confirmed
3
12
4
9
0
Suspected*
1
3
3
3
0
2
0
1
0
1
0
1
1
1
0
Check up samples
negative
All negative
None
0
0
0
1
Not tested
---
Enterotoxigenic E. coli
Enterotoxigenic E. coli is the most common cause of traveler’s diarrhea. People
are the reservoir for this organism. Transmission is usually from consumption of food or
water contaminated with feces from infected persons. The incubation period is 10 to 12
hours if one toxin is present and 24 to 72 hours if both toxins are present. Symptoms
are acute watery diarrhea. Three outbreaks were reported in Illinois from 1998 to 2006.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 – None.
Salmonella
Salmonella is the most common causative agent associated with bacterial
foodborne outbreaks. The incubation period for Salmonella is six to 72 hours.
Symptoms may include diarrhea, vomiting, fever and headache. Several large multistate outbreaks were reported in 2007. One outbreak of Salmonella serotype I 4,5,12:iwas linked to consumption of frozen, not-ready-to-eat pot pies in 41 states. Testing of
pot pies yielded the outbreak strain. Illinois residents were affected by this outbreak. A
concern during this outbreak was the recommended microwave cooking times may vary
by microwave wattage and many persons may not know the wattage of their microwave.
A second multi-state outbreak was linked to a commercial vegetable-coated snack food.
Illnesses were caused by S. ser. Wandsworth and were primarily in infants and toddlers.
The product tested positive for four Salmonella serotypes including Wandsworth. Illinois
residents were affected by this outbreak. This outbreak may have been caused by
73
adding seasoning after the heating step. This seasoning did not undergo a lethal
processing step.
Case definition
A laboratory-confirmed outbreak of Salmonella occurs when bacteria are either
cultured from implicated food or Salmonella of the same serotype is cultured from
clinical specimens from two or more ill individuals.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 - 12 confirmed outbreaks were
reported with 974 people ill (mean = 81 persons ill per outbreak). Outbreaks
occurred in five counties. In addition, two outbreaks were multi-state outbreaks.
Serotypes causing outbreaks included Enteritidis (three outbreaks), Montevideo
(two) and one each for Heidelberg, Infantis, Litchfield, Newport and Typhimurium.
Two outbreaks had two serotypes (Typhimurium and Wandsworth for one outbreak
and Typhimurium and I 4,5,12,i:-). Food handlers were tested in seven of the eight
outbreaks occurring in a facility with food handlers and in all seven outbreaks food
handlers tested positive for Salmonella. In five of the eight outbreaks where food
handlers were present, information was available on food handler illnesses. In two
outbreaks a food handler reported gastrointestinal illness. In three outbreaks they
did not report illnesses. In four of the five outbreaks, food handlers tested positive for
Salmonella. Contributing factors were unknown for two of the 12 outbreaks. For 10
outbreaks contributing factors were identified including food handlers ill or laboratory
positive for a pathogen (six), contaminated raw product (one), contaminated
commercial product (one), contaminated commercial product cooked improperly by
consumer (one), unlicensed product (one) and food not cooked sufficiently (one).
One outbreak had two contributing factors. Food testing was performed in six
outbreaks. In five outbreaks a food tested positive. Foods testing positive were
hummus, unpasteurized milk, spices used in a snack food, pot pies and in one
outbreak both salsa and pigs head meat. In one outbreak, only check up samples
were tested and were negative.
• Individual Descriptions of Confirmed Outbreaks
o An outbreak of S. ser. Newport occurred in the Hispanic community primarily
in Kane County. Ninety-six cases. Isolates from 47 cases tested by PFGE
matched (PFGE pattern: SneO2X8/SneO6B1). Illnesses were linked to
consumption of unpasteurized cheese sold at a local Hispanic grocery store.
Unpasteurized milk from a local dairy farm tested positive for the same PFGE
pattern of Salmonella. The weight slips from this farm were variable over time
possibly indicating diversion of milk from pasteurization. Once the sale of this
unpasteurized cheese was stopped cases also stopped.
o An outbreak of Salmonella ser. Enteritidis in 18 persons occurred in Madison
County in February and was linked to eating at a restaurant. Isolates from
three cases were tested by PFGE and all three matched (Sen07X11/
JEGX01.0034). Twelve persons were laboratory confirmed. One food handler
reported working with diarrhea. Two food handlers (including the one who
reported diarrheal illness) tested positive for Salmonella ser. Enteritidis. No
74
o
o
o
o
o
o
o
o
specific food item was linked to illness.
A multi-state outbreak of S. ser. Typhimurium occurred related to
consumption of lettuce. Seven Illinois residents were affected. Twenty-five
residents matched the outbreak pattern but only seven had a consistent food
history. This lettuce was sold in grocery stores and eaten in private homes.
Two persons tested positive for S. ser. Enteritidis in March in Cook County
after eating at a restaurant. No PFGE testing was done on isolates.
An outbreak of S. ser. Litchfield occurred in Rock Island in May of 2007. Six
confirmed cases reported eating at a restaurant. Food handlers were tested.
The number positive is not known at this time. Isolates from six persons had
two PFGE patterns (CDC pattern: JGXX01.0054 and JGXX01.0053).The
contributing factors were unknown. The restaurant was closed until
employees tested negative.
An outbreak of S. ser. Montevideo (CDC PFGE pattern Xba1: JIXX01.0011)
occurred in Dupage County in April in persons who purchased food at a
grocery store. Nine cases had PFGE performed and all matched. No food
handlers reported illness but one tested positive for S. ser. Montevideo of the
same PFGE pattern as the cases. Pancit Palabok was implicated by
epidemiologic analysis and was prepared by the laboratory confirmed food
handler. Two persons were hospitalized.
Nine individuals who purchased foods from a grocery store in Kane County
became ill with S. ser. Montevideo (CDC PFGE Xba1: JIXX01.0140). Isolates
from three persons were PFGE’d and all three matched. One was a food
handler tested positive for the same PFGE pattern of S. ser. Montevideo.
Samples of green salsa, red salsa and pig head meat from one household
tested positive for S. ser. Montevideo and the isolates matched the case
isolates.
A large outbreak of S. ser. Heidelberg (PFGE pattern Xba: JF6X01.0032, Bln:
JF6A26.0076) occurred in persons after a large outdoor festival in Chicago in
June. The number of persons laboratory confirmed was 191. There were 146
isolates tested by PFGE that had a two enzyme match and five isolates that
had one PFGE enzyme run and matched by one enzyme. An estimated 802
people became ill as a result of this outbreak. Hummus tested positive for S.
ser. Heidelberg. Three food handlers tested positive for the same strain and
reported gastrointestinal illness while working. Illnesses occurred in persons
from multiple states.
A multi-state S. ser. Typhimurium and ser. I 4,5,12:i:- occurred in late 2007.
Pot pie consumption was linked with illnesses. Salmonella was present in pot
pies that were then not sufficiently cooked by consumers resulting in
illnesses. Seven Illinois residents were PFGE matches to this outbreak and
reported consumption of the implicated pot pies. All seven Illinois residents
matched by PFGE (JJPX01.0206/JPXA26.0180).
At least 60 cases of S. ser. Wandsworth and Typhimurium from 19 states
occurred and were PFGE matched. The isolate from one case in Illinois was
PFGE’d and the CDC pattern was WWSX01.0013. Cases were linked to
consumption of Veggie Booty snack food. Two Chicago residents became ill
75
•
with the same strain and reported eating the implicated food. Neither were
hospitalized and both survived.
o Five persons became ill with a diarrheal illness after a group of 20 ate at a
restaurant in DuPage County in July. Two persons tested positive for S. ser.
Enteritidis. Cooperation could not be obtained to get a list of attendees. Five
persons called in with illness relating to the restaurant. One food handler
tested positive for S. ser. Enteritidis. In addition, foods were found improperly
held at room temperature.
o Seven persons reported diarrheal illness after eating foods from a Hispanic
grocery in Chicago. Six cases were confirmed as S. ser. Infantis, PFGE
pattern JFXX01.0069. One food handler tested positive for the same
organism. Check up samples from carnitas were negative for Salmonella.
In 2002, there were six Salmonella outbreaks, five in 2003, seven in 2004, six in
2005 and four in 2006.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
February
March
April
May
June
July
September
Counties of outbreaks
Cook
Dupage
Kane
Madison
Rock Island
Multi-county
Food testing positive
Food handlers positive
Environmental specimen tested
Confirmed
12
974
80
79
0
2
2
1
1
3
2
1
4
2
2
1
1
2
Yes, spices in Veggie
Booty
Yes, hummus
Yes, unpasteurized
milk used for cheese
Yes, pot pies
Yes, salsa and pig
head meat
7 outbreaks
None
Suggested readings
Meyers, S., et. al. Multistate outbreak of Salmonella infections associated with
76
frozen pot pies – United States, 2007. MMWR 2008; 51(47_:1277-80.
Shigella
The Shigella organism is not a common cause of foodborne outbreaks. Instead, it
causes a gastrointestinal illness often transmitted from person-to-person. However,
outbreaks have been associated with consumption of bean dip, lettuce, parsley and
contaminated water. Outbreaks of shigellosis have also been associated with swimming
in contaminated water.
Case definition
The case definition for an outbreak of Shigella is identification of the same
serotype of the bacteria in two or more ill persons.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 - None.
Staphylococcal food poisoning
One type of foodborne illness, classified as intoxication, is caused by enterotoxinproducing strains of S. aureus. Within 30 minutes to eight hours (usually two to four
hours) after eating contaminated food, a person may experience explosive vomiting and
diarrhea. The duration of illness is usually short - less than 24 hours. Humans are
considered to be the primary source of the organism in foodborne outbreaks. S. aureus
can be found in nasal passages, throat and hair and on the skin of healthy people;
bacteria are present in high numbers in cuts, pustules and abscesses. The enterotoxins
produced by S. aureus are heat stable. The organism may produce toxin in foods and
then die so cultures of foods may be negative and yet the foods contained the
staphylococcal enterotoxin that made people ill. Foodborne outbreaks caused by S.
aureus and those caused by the B. cereus type where vomiting predominates have
similar incubation periods and clinical syndromes.
Case definition
Laboratory confirmation of an outbreak attributable to S. aureus requires
detection of enterotoxin in food or organisms with the same phage type in stools or
vomitus of two or more cases or isolation of greater than 105 organisms per gram in
properly handled food.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 – Two confirmed outbreaks were
reported. There was one suspected outbreak that was either S. aureus or B. cereus
but the agent was not confirmed. In two outbreaks, food tested positive. Foods
testing positive were pulled pork and enchiladas.
• Individual Descriptions of Confirmed Outbreaks
o An outbreak of confirmed S. aureus enterotoxin B occurred in 75 persons in
Cook County in June after a catered picnic. Pulled pork was epidemiologically
77
linked to illness and tested positive for S. aureus at 314,000 organisms/gram.
The incubation period was three hours. Food was not kept at proper
temperatures. Three persons tested positive for toxin.
o In June 2007 in Rock Island, enchiladas were served at a work place after
preparation in a private home. Twelve of 22 persons became ill with diarrhea
and vomiting an average of three hours after eating the enchiladas. Five
persons tested positive for S. aureus. Leftover enchiladas also tested positive
with 230,000,000 per gram of S. aureus. Both preparing food ahead and
improper heating may have contributed to the outbreak. Three persons were
hospitalized.
•
Outbreaks of S. aureus: one in 2002, six in 2003, two in 2004, none in 2005 and two
in 2006.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
June
Counties of outbreaks
Cook
Rock Island
Environmental specimen tested
Food testing positive
Confirmed
2
87
43
3
0
2
1
1
0
Yes, pulled pork
Yes, enchiladas
Chemical agents/Fish toxins
This category includes toxins such as ciguatera and scombrotoxin, associated
with fish consumption. Ciguatera toxin poisoning is caused by the ingestion of the toxin
in predatory reef fish, such as barracuda, amberjack and grouper. The toxin is initially
produced by dinoflagellates that are eaten by herbivorous fish, which are then
consumed by the predatory fish. There is a test to detect the toxin in fish. However, the
toxic fish have a normal taste and appearance. The toxin cannot be destroyed by
cooking or freezing. Symptoms of diarrhea and vomiting develop within three to six
hours after consuming contaminated fish. Neurologic symptoms may follow and persist
for weeks or months. These neurologic symptoms include numbness, tingling of the
mouth and extremities, muscle pain and weakness, and reversal of temperature
sensation. There is no diagnostic test or treatment available for humans. A cluster of
nine cases of ciguatera fish poisoning occurred in North Carolina in 2007. Patients
became ill four to 48 hours (median = 12 hours) after consuming amberjack. The toxin
was identified in the fish.
78
Scombroid fish poisoning occurs after persons have consumed fish that contain
high levels of histamine or other biogenic amines. Histamines accumulate when
bacterial enzymes metabolize histidine in fish. Histamines are not destroyed when fish
are frozen or cooked. This occurs when fish is held at high temperatures. Symptoms
include facial flushing, sweating, rash, a burning or peppery taste in the mouth and
diarrhea. More severe symptoms can occur and result in the need for medical
treatment. Prevention is consistent temperature control of fish at less than 41 F at all
times. Rapid cooling of fish after catch is the best method for prevention of scombroid
fish poisoning. Scombridae include tuna and mackerel which have high levels of free
histidine and are the main fish type linked to scombroid poisoning. Other fish implicated
include mahi mahi, amberjack, bluefish, abalone and sardines.
Tetrodotoxin is a heat-stable neurotoxin found in puffer fish. Tetrodotoxin
poisoning occurs after someone consumes puffer fish that is improperly prepared. The
skin and certain internal organs may contain this toxin that is highly toxic to humans.
Importation of puffer fish meat is generally not permitted into the United States.
Mislabeling of fish imported into the United States has led to cases. Symptoms include
numbness of the lips and tongue, paresthesias, a floating sensation and progression of
an ascending paralysis.
Case definition
The case definition for ciguatera toxin outbreaks is the demonstration of
ciguatoxin in epidemiologically implicated fish or a clinical syndrome among persons
who have eaten a type of fish previously associated with ciguatera fish poisoning.
The case definition for scombroid toxin outbreaks is demonstration of histamine
in epidemiologically implicated fish or a clinical syndrome among persons who have
eaten a type of fish previously associated with histamine fish poisoning.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 - One outbreak of tetrodotoxin
poisoning was reported.
• Individual Description of Confirmed Outbreak
o Two of three family members became ill after eating puffer fish in Chicago
in May. Fish tested positive for tetrodotoxin (300-600 ug tetrodotoxin per
100 grams). One family member prepared the fish in a soup. A recall of
imported monk fish, believed to have been improperly labeled puffer fish
occurred. One family member was hospitalized for three weeks with
numbness, tingling of the periorial region and extremities and extreme
weakness. The other family member had minor illness. One family
member who only tasted the soup had no symptoms. Both cases survived.
Although this outbreak occurred only within one family because of the
unusual nature of this outbreak and the known consumption of puffer fish
this was counted as an outbreak.
79
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
May
Counties of outbreaks
Cook
Environmental specimen tested
Food tested
Confirmed
1
2
1
0
1
1
--Yes, fish tested positive
Suggested readings
Cohen, N.J., et. al. Public health response to puffer fish (tetrodotoxin) poisoning
from mislabeled product. J Food Protection 2009: 72(4): 810-817.
Langley, R., et. al., Cluster of ciguatera fish poisoning – North Carolina, 2007.
MMWR 2009; 58 (11): 283-5.
Heavy metals
Occasionally heavy metals can contaminate foods. One source of heavy metals
in foods is leaching of metallic containers into the food.
Case definition
Elevated heavy metal levels in blood in multiple persons linked to a common food
item.
Descriptive Epidemiology
• Number of outbreaks reported in Illinois in 2007 - One outbreak of lead poisoning
was reported.
• Individual Description of Confirmed Outbreaks
In December 2007 a person contacted a physician for severe abdominal pain and was
hospitalized with suspected lead toxicity. The initial case had symptoms of
severe abdominal pain for one month despite multiple medical visits and
hospitalizations. A physician contacted for a second opinion suspected lead
poisoning and hospitalized the patient who had an elevated blood lead level of 88
ug/dL (normal < 20 ug/dl). A suspect product in the household was a colored
powder used as a spice on food. It was improperly labeled as “Do not eat” on the
back and “best food in town” on the front. The food product tested as 87 percent
lead. A second person in the household also consumed the mixture and had an
80
elevated blood lead level. A third person had similar symptoms after sharing food
with the two cases and returned home to Morocco without a diagnosis.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
December
Counties of outbreaks
Rock Island
Environmental specimen tested
Food Tested
Confirmed
1
3
1
0
1
1
--Sindoor used as food
coloring, positive for lead
Parasitic agents
There are a variety of parasitic agents that can cause foodborne or waterborne
outbreaks, for example, Cryptosporidia, Cyclospora and Giardia. The incubation periods
for parasitic agents can be up to 25 days.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 – None reported.
Viral gastroenteritis
Noroviruses are a common cause of gastroenteritis in the United States.
Estimates are that 23 million people are affected by noroviruses in the United States
each year. There are five genogroups (1-5). Genogroup G1 (Norwalk virus,
Southampton virus and Desert shield virus), G2 (Toronota virus, Mexico virus, Hawaii
virus, Bristol virus, Lordsdale virus, camberwall virus, Snow Mountain agent and
Melksham virus) and genogroup G4 infect humans, genogroup G3 has been found in
cattle and genogroup G5 has been identified in mice. Sapoviruses have only been
identified in humans, especially children. In Canada, 11 percent of norovirus negative
outbreaks were positive for sapovirus.
Noroviruses are transmitted through consumption of contaminated food or water,
directly from person to person and from airborne droplets produced during vomiting.
The most common method of spread is via the fecal-oral route. The virus is excreted in
stool and vomitus for up to 10 days. The median infectious dose is 18 viruses. The
incubation period and duration of illness ranges from 24 to 48 hours. Duration of illness
ranges from 12 to 60 hours. Virus shedding peaks 25 to 72 hours after exposure to the
virus. Within 48 to 72 hours after symptom onset, virus concentration in the stool
declines below levels detectable by electron microscopy. Short-term immunity occurs
after infection. Vomiting, diarrhea, headache and body aches are commonly reported. A
common feature of norovirus outbreaks is secondary transmission to household
members not exposed to the implicated food or water.
Humans are the only known reservoir for these viruses. These viruses cannot
replicate outside the human body and therefore will not multiply in food items.
81
Characteristics of the virus that facilitate spread include low infectious dose, high
concentration of virus in stool, strain diversity, environmental stability and prolonged
shedding. Approximately 25 percent of infected persons shed for at least three weeks.
CDC estimates that approximately 50 percent of all norovirus outbreaks are linked to ill
food handlers. Approximately 20 percent of norovirus infected persons are
asymptomatic. Failure of an ill food handler to perform proper handwashing may result
in fecal contamination of food. Illness caused by norovirus can be suspected based on
incubation period, duration of illness, symptoms or by identification of the organism in
stool. Noroviruses can survive freezing and temperatures of up to 60 C and can survive
chlorine levels up to 10 ppm (that exceeds what is normally present in public water
systems).
Outbreaks are not uncommon in closed settings, such as detention facilities,
cruise ships, long-term care facilities and hospitals. An outbreak of norovirus affected
six consecutive cruises on a single ship. Multiple strains of norovirus were identified.
The virus cannot be grown in cell culture; a polymerase chain reaction (PCR) test
is used to diagnose norovirus. Testing for viral gastroenteritis in humans is not useful for
screening individual samples but is useful when multiple samples are available in an
outbreak. Approximately 25 state health department laboratories, including Illinois, can
do the RT-PCR to detect norovirus. Norovirus can be present in stools for up to a week
after illness onset. Immunity is short-lived and appears to be strain specific. Since
there are so many strains, individuals can be repeatedly infected by noroviruses during
their lifetime.
Case definition
Several laboratory tests may help to confirm an outbreak related to norovirus.
These include positive results on RT-PCR, visualization of small round structured virus
(SRSV) in electron microscopy of stool from ill individuals, or a fourfold rise in antibody
titer to norovirus seen in acute and convalescent sera in most serum pairs. Multiple
samples are needed from each outbreak to provide sufficient specimens to verify the
causative agent as norovirus. An outbreak is considered confirmed when at least two ill
persons have positive laboratory results.
Descriptive epidemiology
• Number of outbreaks reported in Illinois in 2007 – Twenty-three suspected
outbreaks of norovirus gastroenteritis, based on clinical syndrome, incubation
period and duration of illness and nine laboratory confirmed outbreaks were
reported. Norovirus outbreaks affected 1,192 people who experienced
compatible illness (median = 17 ill persons per outbreak). The number of ills per
outbreak ranged from three to 526 ill persons. The median incubation period for
the confirmed outbreaks was 34 hours. The norovirus outbreaks occurred in the
counties of Cook, (14), Kane (five), McLean (two) and Tazewell (two), and one
each for DuPage, JoDaviess, McDonough, McHenry, Peoria, Stephenson,
Vermilion, Will and Winnebago. Genotyping information was available on 16
suspect or confirmed outbreaks. Three were G1 (two confirmed and one suspect
outbreak) and 13 were G2 (seven confirmed and six suspect outbreaks). Fifty-six
of the cases sought health care consultation, eight were hospitalized, and there
82
•
were no fatalities. Food handlers were tested for norovirus in six outbreaks and
positive food handlers were identified in all six outbreaks. In 10 of 11 outbreaks
with information available, food handlers reported gastrointestinal illnesses. In
four of the outbreaks, specific food vehicles were implicated. In two of the
outbreaks foods were linked to illness by epidemiologic analysis (taco salad in
one outbreak and raspberry dressing and dill dip in the second outbreak). In the
third outbreak, water had high coliforms and in the fourth outbreak chocolate
strawberries and sandwiches were implicated. Contributory causes were
unknown for 24 outbreaks. Contributing factors in eight outbreaks were food
handler related.
Individual Descriptions of Confirmed Outbreaks
o Three persons became ill after eating at a restaurant in January in Mclean
County.
o Twenty-three persons became ill in March in Chicago after eating at a
restaurant. One person was hospitalized. Three persons tested positive
for norovirus G2. The status of food handler illness was not stated.
o Forty-one persons became ill with norovirus G2 after eating food from the
same restaurant in May in McLean County. Three persons tested positive
for norovirus G2. Three food handlers were ill with gastrointestinal illness
but were not tested. The food vehicle was unknown.
o Forty-four persons became ill in Chicago in May after eating at a
restaurant. Seventeen ill persons tested positive for norovirus G2 and one
ill food handler also tested positive. No specific food item was implicated.
o In July 2007 a large outbreak of norovirus G1 occurred at a conference in
a hotel in Chicago. At least 526 persons attending the conference became
ill. Eight persons tested positive for norovirus G1 type 4. Persons attended
the conference from multiple states and countries. An e-mail survey was
conducted of participants. No specific food item could be linked to illness.
No persons were hospitalized. The status of food handler illness was not
reported.
o In July, an outbreak of norovirus G1 occurred in individuals after attending
a wedding party at a restaurant in McHenry County. Twenty-eight persons
reported illness. One attendee tested positive for norovirus G1 and two
food handlers tested positive. Food handlers did report illness. Water from
the restaurant had high coliforms.
o In October 2007 in Kane County an outbreak of norovirus G2 occurred in
16 persons. Six persons were laboratory confirmed. Taco salad prepared
in a private home and brought to work was implicated by epidemiologic
analysis. Gastrointestinal illness status of taco salad makers prior to the
meal was unknown.
o In October 2007 in Winnebago County an outbreak of norovirus G2
occurred in 17 of 20 coworkers sharing a take out meal. Six persons
tested positive. The median incubation period was 28 hours. Six persons
tested positive including two food handlers. It is unknown if any of these
food handlers were ill before the outbreak. One person was hospitalized
and there were no fatalities. Contributing factors leading to the outbreak
83
included handling of food by infected employees.
o In November, 40 persons became ill with norovirus in DuPage County
after eating at a banquet. Norovirus G2 was identified in stool specimens.
Suggested readings
Moe, C.L. Preventing norovirus transmission: How should we handle food
handlers? CID 2009;48:38-40.
Pang, X.L. Epidemiology and genotype analysis of sapovirus associated
with gastroenteritis outbreaks in Alberta, Canada: 2004-2007. JID 2009:199:547551.
Norovirus
Confirmed
9
738
82
2
0
Suspected*
23
454
20
6
0
January
February
March
April
May
June
July
August
October
November
December
1
0
1
0
2
0
2
0
2
1
0
4
2
1
3
1
0
2
3
3
1
3
Cook
DuPage
Jo Daviess
Kane
Lake
Macomb
McHenry
McLean
Peoria
Tazewell
Vermilion
Will
Winnebago
Food handler positive for pathogen
3
1
0
1
0
0
1
2
0
0
0
0
1
Yes, 3 outbreaks
Food testing
Environmental specimen tested
Yes, 3 outbreaks; water positive for
coliforms in one outbreak
None
11
0
1
4
0
1
1
0
1
2
1
1
0
Yes, 2 outbreaks
Yes, 3 outbreaks
1 outbreak had
sandwiches with
fecal coliforms
None
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
Counties of outbreaks
84
Hepatitis A
Foodborne outbreaks of hepatitis A are uncommon. When they do occur they are
often associated with foods contaminated by infected food handlers. Also, contaminated
produce, such as lettuce or strawberries, also may be a source of illness. The
incubation for hepatitis A is 28 to 30 days. The agent can be found in feces before the
onset of illness.
Descriptive epidemiology
• Number of hepatitis A outbreaks in 2007 – One outbreak was reported.
• Individual Description of Confirmed Outbreak
o Two hepatitis A cases occurred, one with onset on May 24 and one on
May 27 in Woodford County after a family celebration held from May 4
through May 6 in a private home.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
May
Counties of outbreak/s
Woodford
Food handler positive for pathogen
Environmental specimen tested
Food tested
Confirmed
1
2
2
0
0
1
1
No testing
None
None
Recreational Water Outbreaks
Swimming is a very popular recreational exercise. Pool chemicals and filtration
are used as barriers to waterborne pathogen transmission. However, pool chemicals
can also cause injury to persons when levels are not adequately maintained or when
ventilation around pools is not adequate. Recreational water outbreaks can be due not
only to infectious agents but also to chemical agents.
An example is a large outbreak at an indoor hotel waterpark in Ohio that was
believed to be linked to trichloramine in the air. Persons experienced respiratory and
eye irritation. Ventilation at the waterpark was modified and no further cases were
identified.
Descriptive epidemiology
• Number of recreational waterborne outbreaks in 2007 –Two outbreaks were
reported. The outbreaks occurred in JoDaviess and Winnebago County. A total
of 10 persons became ill due to recreational water exposure. Both outbreaks
were confirmed to be caused by Cryptosporidium. There was one person
hospitalized and no fatalities for waterborne outbreaks in Illinois in 2007.
85
•
•
In the first outbreak in JoDaviess county, four persons became ill with three
testing positive for Cryptosporidium after swimming in a water park pool in
August. Pool water could not be tested as the pool was closed for the season at
the time of identification of the outbreak. The cause of the outbreak was
unknown.
Another outbreak occurred in August in Winnebago County. Six persons became
ill and one was hospitalized following swimming in a swimming pool. The source
of water was a well. Six persons were laboratory confirmed. Hyperchlorination of
the pool was done before water samples could be taken.
Suggested readings
Sacke, H., et. al. Pool chemical associated health events in public and residential
settings – United States, 1983-2007. MMWR 2009; 58(18):489-93.
Stansburg, D., et. al. Respiratory and ocular symptoms among employees of a
hotel indoor waterpark resort – Ohio, 2007. MMWR 2009; 58 (4): 81-85.
86
Table 5.
Foodborne and Waterborne Outbreaks in Illinois in 2007
Exposure
IDPH Log
Number
Onset
Date
City
County
Symptoms*
Incubation
Hours
Food Implicated
Agent Implicated
Status
Place of
Preparation
Place Eaten
IL2007-006
1/6
Fithian
Vermilion
AC,D,V
30
Unknown
S
Restaurant
Restaurant
23/40
AC,D
9
Chili
Norovirus
C. perfringens
Type A
IL2007-007
1/6
Sugar Grove
Kane
C
Private home
Private home
IL2007-008
1/6
Chicago
Cook
6/23
AC,D,V
34
Unknown
Norovirus
S
Restaurant
Chicago
Cook
10/40
D,V
36
Unknown
Norovirus G2
S
Restaurant
Restaurant &
Commercial
product
IL2007-012
1/14
IL2007-024
1/18
Marion
Williamson
3/ 4
AC,D,V
12
Unknown
Unknown
U
Restaurant
Restaurant
IL2007-015
1/21
Bloomington
Mclean
3/3
AC,D,V
35
Unknown
Norovirus G2
C
Restaurant
Restaurant
IL2007-054
1/25
Westchester
Cook
19/22
AC,D,V
36
Unknown
Norovirus
S
Restaurant
Restaurant
IL2007-051
2/1
Edwardsville
Madison
18/ U
AC,D
38
Unknown
S. ser. Enteritidis
C
Restaurant
Restaurant
IL2007-059
2/12
Orland Park
Cook
12/20
AC,D,V
32
Unknown
Norovirus
S
Banquet
Banquet
IL2007-044
2/16
Orland Park
Cook
17/29
D,V
33
Unknown
Unknown
U
Work place
IL2007-048
2/25
Chicago
Cook
19/25
AC,D,F,V
36
Unknown
Norovirus G2
S
Restaurant
Restaurant &
Private home
& Bakery
IL2007-087
2/26
Lettuce
S. ser.
Typhimurium
C
Grocery
IL2007-047
3/2
S. ser. Newport
C
Unknown
Home
Grocery store
& private
home
IL2007-064
Norovirus
S
Restaurant
Restaurant&
private home
ExpIl/lExp
7/U
Restaurant
Private home
Multi-state
7/U
D,V
U
multiple
Kane
96/U
D
U
3/11
Orland Park
Cook
19/43
AC,D,V,HA
U
Unpasteurized
cheese
Dill dip&
raspberry
dressing
IL2007-072
3/16
Oak Lawn
Cook
2/U
AC,D,F
U
Unknown
S. ser. Enteritidis
C
Restaurant
Restaurant
IL2007-070
3/24
Chicago
Cook
23/52
AC,D,V
35
Unknown
Norovirus G2
C
Restaurant
Restaurant
IL2007-077
4/9
South Elgin
Kane
8/21
AC,D
U
Unknown
Norovirus
S
Restaurant
Restaurant
87
Exposure
IDPH Log
Number
Onset
Date
City
County
Symptoms*
Incubation
Hours
Food Implicated
Agent Implicated
Status
IL2007-075
4/9
Woodstock
McHenry
6/31
D,V
37
Unknown
Unknown
U
IL2007-073
4/10
East Peoria
Tazewell
91/U
AC,D,V
U
Pasta
Norovirus
S
IL2007-078
4/22
Orangeville
Stephenson
ExpIl/lExp
Place of
Preparation
Place Eaten
31/95
D,V
30
Unknown
Norovirus G1
S
Private home
Private home
1/U
D,V
U
Ground beef
E. coli O157:H7
C
Restaurant
IL2007-089
4/25
Dupage, multistate
IL2007-092
4/26
Dupage
13/U
AC,D
20
Pancit Palabok
S. ser.
Montevideo
C
Restaurant
Restaurant
Restaurant &
private home
& grocery
store
IL2007-088
4/27
St Clair, multistate
1/U
D
U
Ground beef
E. coli O157:H7
C
Commercial
product
Private home
IL2007-083
5/1
Downs
Mclean
41/138
AC,D,V,F
28
Unknown
Norovirus G2
C
Restaurant
Restaurant&
work place
IL2007-084
5/5
Chicago
Cook
44/73
AC,D,V,F
40
Unknown
Norovirus G2
C
Restaurant
Restaurant
IL2007-101
5/9
Chicago
Cook
2/3
Severe
weakness
1/ 2
Puffer fish soup
Tetrodotoxin
C
Private home
Private home
IL2007-102
5/24
Eureka
Woodford
2/U
Jaundice
U
Unknown
Hepatitis A
C
Private home
Private home
IL2007-104
5/26
Moline
Rock Island
6/U
AC,D,V
48
Unknown
S. ser. Litchfield
C
Restaurant
Restaurant
Fairgrounds
IL2007-095
5/26
Woodstock
McHenry
7/17
AC,D,V
9
Unknown
Unknown
U
Private home
& grocery
IL2007-097
5/27
Geneva
Kane
11/34
AC,D,V
38
Unknown
Norovirus G2
S
Restaurant
Restaurant
S. ser.
Montevideo
C
Grocery store
Grocery store
S. ser.
Wandsworth and
C
Commercial
product
Private home
IL2007-100
6/10
Elgin
Kane
9/U
AC,D,F,V
15
Pig head meat;
red and green
salsa
IL2007-112
6/15
Chicago
Cook, multistate
2/U
AC,D,F,V
U
Veggie Booty
snack food
88
Typhimurium
IL2007-103
6/17
Oak Park
Cook
75/112
AC,D,V
3
Pork, Barbeque
S. aureus
C
U
Caterer
Caterer &
private home
Picnic
Banquet
facility
IL2007-107
6/23
Rockford
Winnebago
34/50
AC,D
12
Turkey, roasted
Unknown
IL2007-109
6/29
Crestwood
Cook
D,V
8
Unknown
Unknown
U
Restaurant
Restaurant
IL2007-110
6/29
Milan
Rock Island
12/22
AC,D,V
3
Enchiladas
C
C
Private home
Fair &
Restaurant
Work place
Hummus
S. aureus
S. ser.
Heidelberg
IL2007-115
6/30
Chicago
Cook
802/U
AC,D,F
48
Il2007-111
7/1
Galena
JoDaviess
5/U
D,V
33
Unknown
Norovirus
S
Restaurant
Restaurant
IL2007-119
7/3
Chicago
Cook
3/5
AC,D,F
70
Unknown
Campylobacter
S
Restaurant
Restaurant
IL2007-130
7/16
Chicago
Cook
7/U
AC,D,F,V
48
Unknown
C
Grocery Store
Private home
Cook
526/1322
AC,D,F,V
U
Unknown
C
Hotel
Hotel
Chicago
Cook
3/3
AC,D
2
S
Restaurant
Work place
7/23
Aurora
Kane
7/18
AC,D
14
Unknown
Chicken,
shredded
S. ser. Infantis
Norovirus G1,
Type 4
S. aureus/B.
cereus
IL2007-123
7/16
Chicago
IL2007-122
7/20
IL2007-121
C. perfringens
C
Restaurant
Work place
IL2007-126
7/25
Bloomingdale
Dupage
5/20
AC,D,F
60
Unknown
C
Restaurant
Restaurant
IL2007-124
7/26
Chicago
Cook
12/14
AC,D
7
Beef Burrito
S. ser. Enteritidis
B. cereus/C.
perfringens
S
IL2007-127
7/28
Villa Park
DuPage
38/52
AC,D,V,HA
53
Unknown
Unknown
U
Restaurant
Restaurant &
Banquet
Work place
Restaurant &
Banquet
IL2007-129
7/28
Woodstock
McHenry
28/98
AC,D,V
36
Ice water
Norovirus G1
C
Restaurant
Restaurant
IL2007-128
7/29
Macomb
McDonough
4/15
AC,D,V
28
Unknown
Norovirus
S
Restaurant
Work place
IL2007-141
7/30
Cameron
Warren
3/3
AC,D,F,V
84
E. coli O157:H7
S
Private home
Private home
IL2007-203
8/1
Rock Island
3/3
Abdominal
pain
U
Unknown
Sindoor
cosmetic
powder
Lead
C
IL2007-131
8/4
Shorewood
Will
23/49
AC,D,F,V
48
Unknown
Norovirus
S
Commercial
product
Banquet
facility
Private home
Banquet
facility
IL2007-132
8/4
Des Plaines
Cook
9/U
AC,D,HA,V
36
Unknown
Norovirus
S
Restaurant
Restaurant
IL2007-187
8/5
Chicago
Cook
2/2
D,V
3
Unknown
Unknown
U
Restaurant
Restaurant
IL2007-133
8/5
Hodgkins
Cook
4/4
D
5
Unknown
Unknown
U
Restaurant
Restaurant
3/3
89
Fair
IL2007-138
8/16
Chicago
Cook
42/U
AC,D,F,V
U
Unknown
Norovirus G2
S
Sailing Club
Sailing Club
IL2007-143
8/23
Melrose Park
Cook
3/5
AC,D,V
3
Unknown
U
Restaurant
Restaurant
Multi-county
7/U
AC,D,V
U
Pot pie
Unknown
S. ser.
Typhimurium & I
4,5,12:i:-
IL2007-163
9/5
C
Commercial
product
Private home
IL2007-156
9/9
Chicago
Cook
3/ 4
D,V
48
Unknown
Unknown
U
Restaurant
Fair
IL2007-153
9/11
Effingham
Effingham
10/U
AC,D,V
72
Unknown
E. coli O157:H7
C
Restaurant
IL2007-155
9/16
Fairfield
Wayne
18/U
AC,D,F
72
Unknown
C. jejuni
C
Restaurant
Private home
&Caterer&
Church
IL2007-160
9/27
Evanston
Cook
3/U
AC,D,V
14
Unknown
Unknown
U
Restaurant
IL2007-162
10/7
St. Charles
Kane
16/19
AC,D,V
22
Unknown
Norovirus G2
S
Restaurant
Grocery store
& Private
home
IL2007-166
10/9
Streamwood
Cook
3/3
D,V
6
Unknown
Unknown
U
Restaurant
Private home
IL2007-188
10/13
Orland Park
Cook
7/20
D,V
10
Unknown
Unknown
U
IL2007-164
10/14
Peoria
Peoria
39/87
AC,D,V
36
Unknown
Norovirus
S
Restaurant
Banquet
Facility
Park
Banquet
facility
IL2007-167
10/20
Aurora
Kane
16/26
AC,D,V
34
Taco salad
Norovirus G2
C
Private home
Work place
IL2007-184
10/26
Rockford
Winnebago
17/20
AC,D,V
28
Unknown
Norovirus G2
C
Work place
IL2007-173
10/31
Morton
Tazewell
17/24
AC,D,V
34
Unknown
Norovirus
S
IL2007-180
11/5
Chicago
Cook
14/16
D,V
31
Unknown
Norovirus
S
IL2007-177
11/11
Winfield
DuPage
40/56
AC,D,F,HA,V
35
Unknown
Norovirus G2
C
Restaurant
Restaurant &
private home
Grocery store
& Caterer
Banquet &
restaurant
IL2007-179
11/11
Wheeling
Cook
2/11
AC,D
5
Unknown
U
Restaurant
Restaurant
IL2007-210
11/17
Chicago
Cook
12/12
AC,D
12
Beef stew
Unknown
B. cereus/C.
perfringens
S
Restaurant
Private home
IL2007-185
11/22
Chicago
Cook
14/15
AC,D,V
1
Turkey
C. perfringens
C
Caterer
Work place
IL2007-191
12/2
Rolling Meadows
Cook
28/50
AC,D,V
34
Unknown
Norovirus
S
Restaurant
Park
IL2007-193
12/7
Geneva
Kane
11/13
AC,D,V
33
Norovirus G2
S
Restaurant
Restaurant
IL2007-194
12/8
Elk Grove
Village
Cook
13/26
AC,D,V
40
Unknown
Chocolate
strawberries &
deli sandwich
Norovirus
S
Caterer
Work place
90
Church
Private home
Work place
Tavern
Banquet &
Restaurant
IL2007-206
12/16
Chicago
Cook
6/11
AC,D
4
Unknown
Unknown
U
Restaurant
Restaurant
IL2007-207
12/21
Chicago
Cook
5/6
AC,D,V
25
Unknown
Unknown
U
Restaurant
Restaurant
Roasted pork
C. perfringens
C
Restaurant
Private home
Il2007-205
12/24
Chicago
Cook
12/18
AC,D
14
*
BA=body ache, BD=bloody diarrhea, D=diarrhea, F=fever, H=headache, V=vomiting, AC=cramps
91
Giardiasis
Background
Giardia is the most commonly diagnosed intestinal parasite in public health
laboratories. A common intestinal parasite of children, especially those attending day
care, it is spread from person to person through fecal-oral transmission and has a
median incubation period of seven to 10 days. Many infections are asymptomatic and
repeated infections can occur in the same person. There are three species of giardia:
G. lamblia, G. agilis and G. muris. The main human pathogen is G. lamblia. Cysts are
infective immediately upon excretion and can remain viable for months. The infectious
dose is low; as few as 10 cysts can cause infection and excretion can continue for
months. Giardiasis also affects domestic and wild mammals including cats, dogs, cattle,
deer, and beavers.
Persons at greatest risk are children in day care facilities, close contacts of
these children, men who have sex with men, backpackers, persons in contact with
infected animals, campers, and persons drinking from shallow wells contaminated by
run-off with the organism. The most commonly identified intestinal parasite in
international travelers is G. lamblia. Giardiasis peaks in late summer and early fall.
Metronidazole is the most frequent treatment in the United States.
Approximately 85 percent of infections can be diagnosed with a single stool
specimen. Diagnosis is made by identification of the parasite in wet mount staining with
trichrome or iron hematoxylin, by direct fluorescent antibody detection, or by enzyme
immunosorbent assay.
Because of its long period of communicability, low infectious dose and
environmental resistance, giardiasis is easily transmitted. Preventive measures should
include practicing good hygiene, avoiding water or food that might be contaminated and
avoiding fecal exposure during sex with infected persons.
In 2007, the CDC received reports on 19,794 cases. Illinois was fourth in the
nation in the number of cases reported. The incidence of giardiasis was highest for the
northern states from 2006 through 2008. The peak onset of illness occurred annually
during early summer through early fall. During this time period giardiasis was reportable
in 45 states. The number of reported cases was highest in children aged one to nine
years of age and adults aged 35 to 44 years.
Case definition
The case definition for giardiasis in Illinois is the presence of diarrhea and the
identification of Giardia trophozoites or cysts in stool, or detection of antigen by the
ELISA antigen test. Probable cases are those without laboratory confirmation but who
are clinically compatible and epidemiologically linked to a confirmed case.
Descriptive epidemiology
• Number of cases (confirmed and probable) reported in Illinois in 2007 – 866 (fiveyear median = 807); the incidence rate was seven per 100,000 population. All but
two of the cases were confirmed. Reported cases increased from 2006 (See Figure
92
•
•
•
•
•
•
•
•
•
•
42).
Age - Mean age of cases was 27 years. The age group with the highest incidence
was 1 to 4 years of age, which included 167 cases (24 per 100,000), followed by 5
to 9 years of age (12 per 100,000) (Figure 43).
Gender – Fifty-four percent were male.
Race/ethnicity – Sixty-five percent were white, 17 percent were African American, 12
percent were Asian and 5 percent were other races; 9 percent were Hispanic. There
were a significantly lower proportion of whites with giardiasis compared to the Illinois
population and a higher proportion of Asians with giardiasis compared to the Illinois
population.
Seasonal variation - More cases occurred in the summer months (Figure 44).
Geographic variation - For 2007, the counties with the highest incidence rates per
100,000 included Cass (22), McDonough (18), Logan (16) and Woodford (14).
Clinical - Symptoms reported by cases were diarrhea (84 percent), vomiting (25
percent), and fever (15 percent). Thirteen percent were hospitalized. No fatalities
were reported. At least 147 cases were asymptomatic.
Reporters – Cases were most frequently reported by laboratory staff (54 percent)
and infection control professionals (31 percent).
Employment – Cases reported working in the following occupations: day care center
(one case), food service (six cases), health care worker (10 cases), residential
facility (two cases) and other sensitive occupation (11 cases).
Risk Factors – Seventy-nine of 422 (19 percent) reported travel to another country.
The three countries most frequently visited were India (11 cases), Mexico (nine
cases) and Russia (eight). Fifty-six of 432 (13 percent) of cases traveled to another
state. Wisconsin (nine cases) was the most common state visited. Thirty-seven of
442 cases (8 percent) reported drinking well water. Thirty-two of 425 cases (7
percent) of cases reported swimming in non-chlorinated water, while 50 of 417
cases (12 percent) reported swimming in chlorinated water. Forty-eight of 440 (11
percent) had contact with a residential facility and three cases reported attending or
residing in a residential facility. Thirty-four of 438 (8 percent) had contact with a day
care facility and 11 cases attended or resided in a day care center.
Outbreaks – No giardiasis outbreaks were reported in 2007.
Summary
Giardiasis cases increased in 2007 compared to the previous five-year median
(807). Whites were underrepresented in the case population for giardiasis (65 percent)
compared to their representation in the Illinois population (73 percent). Asians were
overrepresented in the case population for giardiasis (12 percent) as compared to the
Illinois population (3 percent). The mean age of cases was 27 years, and more cases
occurred in the warmest months of the year.
Suggested readings
Yoder, J.S., et. al. Cryptosporidiosis surveillance – United States, 2006-2008 and
Giardiasis surveillance – United States, 2006-2008. MMWR 2010; 59 (SS-6).15-25.
93
Number of cases
Figure 42. Giardiasis Cases in Illinois, 2002-2007
1000
800
871
861
807
866
772
695
600
400
200
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 43. Giardiasis Cases in Illinois by Month, 2007
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Month of onset
Incidence per 100,000
Figure 44. Incidence by Age of Giardiasis Cases in Illinois, 2007
30
20
10
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
Age in years
94
30-39 yr
40-49 yr
50-59 yr
>59 yr
Hansen’s Disease
Background
Hansen’s disease or leprosy is caused by Mycobacterium leprae. This organism
causes a chronic bacterial disease of the skin. Most of the cases diagnosed in 2006
were identified in India. The disease is endemic in some parts of the United States
including California, Louisiana, Hawaii, Texas and Puerto Rico.
Case definition
A clinically compatible case that is laboratory confirmed. Only new cases, not
recrudescent cases should be counted.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – One case of leprosy was reported
in Illinois in 2007.
• Individual case description – This case was a 41-year-old Cook County resident.
The specimen was examined at the National Hansen’s Disease Laboratory in
Baton Rouge, Louisiana. This patient was born in the Philippines and had
traveled to Manila. He believes his onset began when he was 12 years of age. If
that is the situation, then this case should not have been counted in the annual
totals.
Summary
One case of Hansen’s disease was reported in Illinois in 2007. Due to a previous
history of Hansen’s disease this case should not have been counted as an acute case.
95
Hemolytic Uremic Syndrome (HUS)
Background
Hemolytic uremic syndrome (HUS) is characterized by acute hemolytic anemia,
thrombocytopenia and renal insufficiency. Many microbes including Shigella
dysenteriae, Salmonella ser. Typhi, Campylobacter jejuni and E. coli O157:H7 have
been linked to HUS. Bacteria, such as E. coli O157:H7 produce a toxin that can cause
vascular cell damage. The most serious sequelae from infection with Shiga toxinproducing E. coli in people is HUS. In a study using CDC FoodNet sites from 2000 to
2006, 6 percent of persons with E. coli O157:H7 developed HUS. The highest
proportion of HUS cases occurred amongst children less than five years of age. In a
study of HUS in Italy, consumption of raw milk was linked to HUS.
HUS occurs primarily in children younger than 5 years of age after infection by
an organism producing shiga toxin and causing diarrhea. HUS usually occurs within two
to 14 days after onset of diarrhea. Almost half of children with HUS require dialysis. The
illness can involve the central nervous system (CNS), pancreas, heart and other
organs. During 2007, 292 cases of HUS were reported to CDC from 37 states.
Antibiotic therapy has been identified as a risk factor for HUS development;
therefore, if antibiotic therapy is being considered, it should be withheld for treatment of
patients with diarrhea until (at least) a culture confirms that E. coli O157:H7 is not
present in a stool specimen.
Case definition
Laboratory criteria are both acute anemia with microangiopathic changes (i.e.
schistocytes, burr cells or helmet cells) on peripheral blood smear and acute renal injury
evidenced by either hematuria, proteinuria, or elevated creatinine level (i.e. greater than
or equal to 1.0 mg/dL in a child aged less than 13 years or greater than or equal to 1.5
mg/dL in a person aged greater than or equal to 13 years, or greater than or equal to 50
percent increase over baseline).
A probable case is an acute illness diagnosed as HUS or TTP that meets the
laboratory criteria in a patient who does not have a clear history of acute or bloody
diarrhea in the preceding three weeks, or an acute illness diagnosed as HUS or TTP
that a) has onset within three weeks after onset of an acute or bloody diarrhea and b)
meets the laboratory criteria except that microangiopathic changes are not confirmed.
A confirmed case is an acute illness diagnosed as HUS or TTP that both meets
the laboratory criteria and began within three weeks after onset of an episode of acute
or bloody diarrhea.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – Five cases were reported to CDC
(median = 5) (Figure 45).
• Of the five cases, three also were listed as an E. coli O157:H7 case. Four cases
were probable and one was confirmed.
• Age - The five HUS cases reported to CDC ranged from 3 to 57 years of age. Four
96
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•
•
•
•
cases were younger than 6 years of age.
Sex – Three cases were female and two were male.
Race/ethnicity – All cases were white; one was reported as Hispanic.
Seasonal - Onsets occurred in June to November.
Geographic location – Counties in which cases occurred were Cook, Kane, Macon,
Whiteside and Will counties.
Clinical – Four cases reported diarrhea, and all four reported having bloody
diarrhea. One case reported fever. All cases were admitted to the hospital. All cases
required dialysis. No cases were fatal.
Summary
Five cases of HUS were reported by Illinois to CDC in 2007. Three of the five
cases were known to have had E. coli O157:H7.
Suggested readings
Centers for Disease Control and Prevention. FoodNet 2007 Surveillance Report.
Atlanta: U.S. Department of Health and Human Services, 2009.
Gould, L.H., et. al., Hemolytic uremic syndrome and death in persons with
Escherichia coli O157:H7 infection, foodborne diseases active surveillance network
sites, 2000-2006. CID 2009; 49: 1480-85.
Scavia, G., et. al., Consumption of unpasteurized milk as a risk factor for
hemolytic uremic syndrome in Italian children. CID 2009;48:1637-8.
Number of cases
Figure 45. Hemolytic Uremic Syndrome Cases in Illinois, 20022007
10
5
8
5
4
5
4
3
0
2002
2003
2004
2005
Year
97
2006
2007
Hepatitis A
Background
Hepatitis A virus is transmitted though the fecal-oral route by person-to-person
contact and by contaminated food, water or fomites. HAV infection can spread in
household members, through day care centers, among persons who consume
contaminated or uncooked food handled by infected workers and among men who have
sex with men (MSM). It is one of the most frequently reported vaccine preventable
diseases. There is only one serotype, and immunity after infection is lifelong. Young
children who are frequently asymptomatic when infected may play an important role in
HAV transmission in communities. The incubation period is 15 to 50 days. Onset of
illness with HAV can be abrupt with fever, anorexia, nausea and abdominal discomfort,
followed by jaundice. The disease can vary from one to two weeks of mild symptoms to
a severe illness lasting months. Severity generally increases with age, and many
infections are asymptomatic, especially in young children. Peak levels of the virus
appear in the feces one to two weeks before symptom onset and diminish rapidly after
symptoms appear. Serologic testing for IgM anti-HAV is required for laboratory
confirmation of hepatitis A infection. IgM anti-HAV becomes detectable five to 10 days
after exposure and can persist for up to six months.
Hepatitis A virus infection can be prevented by good personal hygiene,
particularly handwashing, pre-exposure or post-exposure immunization with immune
globulin (IG), and pre-exposure immunization with HAV vaccine. The administration of
IG for persons exposed to HAV is 85 percent effective in preventing symptomatic HAV
infection if given within two weeks of exposure and may prevent infection entirely if
given soon after exposure. The effect of IG starts within hours of administration and
provides from three to six months of protection. Without post-exposure prophylaxis
(PEP), the secondary attack rate ranges from 15 percent to 30 percent in households
with an HAV case. For PEP for non-immune persons who have been exposed to HAV
through sexual or household contact, a single dose of hepatitis A vaccine or IG should
be given. The second dose should be administered to complete the series. For persons
12 months to 40 years of age, vaccine is recommended within two weeks of exposure.
For persons aged 41 and older IG is perferred. For children younger than 12 months,
immuncompromised persons, persons who have chronic liver disease and persons
contraindicated for vaccine should be given IG. In child care centers, vaccine or IG
should be given to all non-immune staff members and attendees if a case of hepatitis A
is identified in children or employees or if cases are recognized in two or more
households of center attendees. If children with diapers are not present, only classroom
contacts of the hepatitis A case need PEP. If cases occur in three or more households,
PEP should be considered for household members of center attendees. Other food
handlers at the same establishment as a food handler with hepatitis A should receive
PEP. IG or vaccine to patrons could be considered if during the time when the food
handler was likely to be infectious, the food handler both directly handled uncooked or
cooked food and had diarrhea or poor hygiene and patrons can be treated within two
weeks. International travelers to countries with high or intermediate levels of hepatitis A
should receive protection through vaccination or IG depending on how long before their
98
travel they seek medical advice.
In 1995, a hepatitis A vaccine was licensed for individuals older than two years of
age. The vaccine was recommended for individuals traveling to areas where there is a
higher endemnicity rate. In 2006, ACIP recommended routine vaccination of all children
aged 12 to 23 months after a vaccine was licensed for children aged 12 to 23 months.
Recommendations are for vaccine use in children at 12-23 months. Catch-up
vaccination of older children in selected areas and vaccination for high-risk persons
(travelers to endemic areas, men who have sex with men and illicit drug users).
Travelers to developing countries are at higher risk for hepatitis A. About three-quarters
of travel-related cases in the United States, are due to travel to Central or South
America. Outbreaks can occur in men who have sex with men communities. Outbreaks
have also occurred in methamphetamine users. In Alaska there was a drop in the
incidence rates for acute hepatitis A from 60 per 100,000 in 1972-1995 to 0.9 in 20022007. The National Immunization survey provides annual estimates of vaccine
coverage in states. In Illinois, 37 percent of children aged 24 to 35 months were
vaccinated with at least one dose of hepatitis A vaccine as compared to 26 percent in
2006. In Chicago the percent vaccinated was 47 percent. Nationally, the percent in
2007 was 47 percent.
Hepatitis A is typically transmitted from person to person through the fecal-oral
route. Occasionally, foodborne transmission occurs when an HAV-infected food handler
contaminates food that is not later cooked. Food handler associated outbreak
characteristics include the presence of an HAV infected food handler who worked while
infectious and had contact with uncooked food or food after it had been cooked,
secondary cases among other food handlers who ate food contaminated by the index
case and low attack rates in patrons.
There were 2,979 acute hepatitis A cases reported in the United States in 2007.
The hepatitis A rate in the United States in 2007 was one case per 100,000. The
highest rate was in those 20 to 39 years of age. The incidence rate was 1.4 per
100,000 for Hispanics and 0.6 for non-Hispanics. Hepatitis A cases have declined
probably due to the recommendation for routine childhood vaccination. In the prevaccine era hepatitis A was highest in children five to 14 years of age, hepatitis A rates
have declined more sharply in age groups covered by vaccine.
The mortality rates in the United States due to hepatitis A were 32 percent lower
in the post-vaccination era than in the pre-vaccine era.
Case definition
The CDC case definition for a case of hepatitis A is used in Illinois: an illness
with a discrete onset of symptoms and jaundice or elevated serum aminotransferase
levels, and IgM anti-HAV positive serology.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – 118 (five-year median = 176) (see
Figure 46). The overall incidence rate for hepatitis A was 0.95 per 100,000.
• Age – Ages ranged from two months to 94 years of age (mean = 41 years). The
99
•
•
•
•
•
•
•
highest number of cases was reported in the 20 to 29 year age group (see Figure
47).
Gender – Forty-one percent of cases were female.
Race/ethnicity - Seventy-seven percent were white, 10 percent were Asian, 5
percent African American, and 8 percent other races; 24 percent were Hispanic.
Hispanics were overrepresented in the case population as compared to the Illinois
population.
Employment - Three hepatitis A cases were food handlers and two were in health
care workers.
Seasonal variation - Cases occurred throughout the year (see Figure 48).
Geographic variation – Cases were reported from 25 counties. Cook County
reported the highest number (41 cases), followed by Dupage (16) and Kane (15).
Hospitalizations and deaths - Forty-eight percent of cases were hospitalized. No
deaths were linked to acute hepatitis A.
Reporters – Forty-six percent of cases were reported by non laboratory hospital
personnel and 41 percent were reported by laboratories.
Summary
Hepatitis A cases have begun declining in the state. The incidence rate (0.95 per
100,000) was similar to the national incidence (1 per 100,000). The number of cases
reported in 2007 was lower than the five-year median. Hispanics were overrepresented
in hepatitis A cases.
Suggested readings
Chaves, S.S., et. al. Hepatitis A vaccination coverage among children aged 2435 months – United States, 2006 and 2007. MMWR 2009; 58(25): 689-694.
Daniels, D., et. al. Surveillance for acute viral hepatitis – United States, 2007.
MMWR 2009; 58 (SS-3): 1-27.
Novak, R., et.al. Update: Prevention of hepatitis A after exposure to a hepatitis A
virus and in international travelers. Updated recommendations of the Advisory
Committee on Immunization Practices. MMWR 2007; 56(41):1080-84.
Singleton, R.J., et. al. Impact of a statewide childhood vaccine program in
controlling hepatitis A virus infections in Alaska. Vaccine 2010; Jul 14.Epub.
Vogt, T.M., et. al. Declining hepatitis A mortality in the United states during the
era of hepatitis A vaccination. JID 2008;197:1282-8.
100
Number of cases
Figure 46 . Hepatitis A Cases in Illinois, 2002-2007
300
262
186
200
176
130
118
109
100
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 47. Number of Hepatitis A Cases in Illinois by Age, 2007
30
20
10
0
<1 yr
1-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
50-59 yr
>59 yr
Year
Number of cases
Figure 48. Hepatitis A Cases in Illinois by Month, 2007
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Year
101
Jul
Aug
Sep
Oct
Nov
Dec
Hepatitis B
Background
Hepatitis B virus is a vaccine-preventable bloodborne and sexually transmitted
virus. It is acquired by percutaneous and mucosal exposure to blood or body fluids from
an infected person. Men who have sex with men (MSM) are at increased risk for
hepatitis B. Approximately 35 percent of cases of acute hepatitis B occur in people who
report no recognized risk factor. The most commonly reported risk factors for
transmission in the United States are high-risk sexual activity and injection drug use.
The incubation period is 45 to 180 days (average 60 to 90 days). Positivity for HBeAg is
linked to an increased risk of hepatocellular carcinoma.
Fewer than half of acute hepatitis B cases will have jaundice (less than 10
percent of children, and 30 percent to 50 percent of adults). The onset is usually
insidious with anorexia, nausea, vomiting, abdominal discomfort, jaundice, occasional
arthralgias and rash. Chronic HBV infection is found in about 0.5 percent of adults in
North America. An estimated 15 percent to 25 percent of persons with chronic hepatitis
B will progress to cirrhosis or hepatocellular carcinoma.
A vaccine became available in 1982. In Illinois, hepatitis B vaccination in children
was mandated in 1997. CDC also recommends vaccination for MSMs, certain travelers,
injection drug users, heterosexuals with multiple sex partners or with sexually
transmitted diseases, clients or staff in developmentally disabled institutions, health
care workers with blood contact, some immigrants, hemodialysis patients, household
contacts and sexual partners of hepatitis B virus carriers and male prisoners. During
2007, 4,519 acute hepatitis B cases were reported to CDC from across the United
States. There were 2,323 chronic hepatitis B cases reported to CDC.
In the United States there has been an 80 percent decrease in hepatitis B since
1990, the year before the national strategy for vaccination was started. In 2007, the
overall rate of acute hepatitis B was 1.5 per 100,000. Thirty-eight percent had greater
than one sexual partner and 12 percent reported surgery prior to onset. Ten percent
reported homosexual activity. Most of the cases were in homosexual or bisexual men
(72 percent). Injection drug use was reported by 15 percent of persons. Seventy-six
percent were jaundiced, 40 percent were hospitalized and 1.5 percent died. Universal
vaccination of children against hepatitis B has reduced hepatitis B incidence rates in
younger age groups.
Case definition
The CDC case definition is used as the surveillance case definition for hepatitis
B in Illinois: a clinical illness with a discrete onset of symptoms and jaundice or elevated
serum aminotransferase levels, and laboratory confirmation. Laboratory confirmation
consists of IgM anti-HBc-positive (if done), or HbsAg-positive, and IgM anti-HAVnegative (if done).
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 - 130 confirmed acute cases (five102
•
•
year median =130) (see Figure 49). The overall one-year incidence rate of
reported acute hepatitis B in Illinois was 1 case per 100,000 population. Note:
CDC had 129 recorded for 2007. For the purposes of this report we will use 130.
• Age – Most cases of acute hepatitis B occurred in those greater than 20 years of
age (Figure 50). Ages ranged from 15 to 86 (mean = 45 years).
• Gender - Fifty-eight percent were male.
• Race/ethnicity – Forty-one percent of cases were African American, 53 percent
were white and 2 percent were Asian; 9 percent were Hispanic.
Geographic location – Counties reporting the most cases included Cook County (53
cases) followed by Will County (12) and Dupage (10).
Symptoms/outcomes – Forty-nine percent were hospitalized. One fatality was
reported.
Summary
There were 130 confirmed acute hepatitis B cases reported in Illinois in 2007.
Almost 50 percent of cases were hospitalized.
Suggested readings
Daniels, D., et. al. Surveillance for acute viral hepatitis – United States, 2007.
MMWR 2009; 58 (SS-3): 1-27.
Wasley, A., et. al., The prevalence of hepatitis B virus infection in the United
States in the era of vaccination. JID 2010; 202 (2): 192-201.
Number of cases
Figure 49. Hepatitis B Cases in Illinois, 2002-2007
200
185
166
130
150
130
111
130
100
50
0
2002
2003
2004
2005
Year
103
2006
2007
Number of cases
Figure 50 . Age Distribution of Hepatitis B Cases in Illinois, 2007
40
30
20
10
0
<1 yr
1-4 yr
5- 9 yr
1 0-19 yr
20-29 yr
Yea r
104
30-39 yr
40-4 9 yr
50 -59 yr
>59 yr
Hepatitis C, Acute
Background
Hepatitis C virus (HCV), an RNA virus, is the most common chronic bloodborne
infection in the United States. There are at least six distinct genotypes of HCV; types 1a
and 1b are most common in the United States. It is estimated that 1.8 percent of United
States residents have been infected with HCV. The incubation period for HCV ranges
from two weeks to six months, most commonly six to nine weeks. Many individuals are
asymptomatic and only a small proportion become jaundiced. Forty percent of infected
adults are symptomatic, and 85 percent of adults with acute hepatitis C develop
persistent infection. Acute hepatitis C is uncommon. WHO estimates that 170 million
people worldwide are infected with HCV.
The most efficient route of transmission is by direct percutaneous exposure (e.g.,
blood or blood product transfusion, organ or tissue transplants, and sharing of
contaminated needles between injection drug users [IDUs]). Low efficiencies of
transmission occur from sexual and household exposure to an infected contact.
Transmission of HCV has been reported from patient to health care worker. The
majority of HCV cases are in IDUs. The virus has been shown to be transmitted by the
use of shared drug preparation equipment such as drug cookers and filtration cotton. In
the United States, injection drug use accounts for 60 percent of HCV infection, sexual
contact (20 percent) and other exposures (household, perinatal and occupational) for
10 percent. Ten percent of cases have no identified risk factor. The rate of transmission
after needle-stick injury from a known infected person is less than 10 percent. The
prevalence of HCV in non-injection drug users in a study in Italy was 20 percent.
Hepatitis C is the most common indication for liver transplantation in adults and
accounts for about 40 percent of all transplants in the United States. About 50 percent
to 80 percent of patients with pretransplantation viremia develop hepatitis in the liver
graft.
The hepatitis C virus can cause chronic hepatitis, cirrhosis and hepatocellular
carcinoma. Among adults who had acute hepatitis C, 26 percent to 50 percent
developed chronic active hepatitis and 3 percent to 26 percent developed cirrhosis. In a
study of transfusion related hepatitis C in the United States from 1968 through 1980,
the risk for developing cirrhosis was 17 percent. Heavy alcohol use increased the risk
for developing cirrhosis. Anti-HCV positive persons had a 5- to 50-fold higher risk of
primary hepatocellular carcinoma compared to anti-HCV negative patients. These
sequelae typically take 20 or more years to develop. In a multi-site study of acute HCV
infection in the United States, with seroconversion to positive for hepatitis C, 64 percent
of persons were asymptomatic. Sixty-six percent were injection drug users. At least six
cases of acute hepatitis C in Nevada in 2007 had recently been to the same endoscopy
clinic and transmission was suspected of having occurred after the re-use of syringes
on individual patients and use of single-use medication vials on multiple patients.
Routine screening for HCV infection is recommended only for persons who have
a history of ever injecting drugs, recipients of clotting factor concentrates prior to 1987,
recipients of blood transfusions or solid-organ transplants prior to July 1992, and
105
chronic hemodialysis patients. Screening is also recommended for sex partners of
HCV-infected persons, infants 12 months or older who were born to HCV-infected
women, and health care workers after accidental needle-sticks or mucosal exposure to
anti-HCV-positive blood. There is no vaccine or effective post-exposure prophylaxis to
prevent HCV infection.
Diagnostic tests for HCV infection include serologic assays for antibodies and
molecular tests for viral particles. Screening tests for HCV include enzyme
immunoassays (EIAs) to measure anti-HCV antibody. While these tests are highly
sensitive, they do not distinguish between acute, chronic or resolved infections. Falsepositive results are common, resulting in the need for supplementary testing. Diagnostic
testing for HCV should include use of both an enzyme immunoassay (EIA) and
supplemental or confirmatory testing with a more specific assay such as the
recombinant immunoblot (RIBA, Chiron Corporation). RIBA results are reported as
positive, indeterminate or negative. It is not as sensitive as the EIA and should not be
used for screening.
Persons with chronic hepatitis C should not drink alcohol and should be
vaccinated for hepatitis A and hepatitis B. HCV-positive persons should not donate
blood, organs, tissues or semen. There is insufficient data to recommend that infected
persons change sexual practices with steady partners. HCV-positive household
members should not share toothbrushes or razors.
Treatment for hepatitis C may be recommended for persons with elevated serum
alanine aminotransferase (ALT) and tests that indicate the presence of circulating HCV
RNA. HCV RNA levels do not correlate with grade or stage of disease. HCV is divided
into six genotypes. Genotype is a predictor of response to therapy. Genotype 1a and 1b
HCV infection, the most common types in the United States, have a poorer response to
therapy than other types. Response to therapy is higher in those with genotypes 2 and
3.
In the United States, 845 acute hepatitis C cases were reported to CDC (0.5 per
100,000). The most common risk factor reported was intravenous drug use reported by
48 percent followed by greater than one sexual partner (42 percent) and surgery (20
percent). In 2007, 71 percent of persons reported jaundice, 49 percent were
hospitalized and 0.5 percent died.
Case definition
The CDC case definition, which is used in Illinois, is a discrete onset of
symptoms with either jaundice or liver enzymes (ALT or AST) greater than 2.5 x upper
limit of normal and negative serology for acute hepatitis A and hepatitis B and positive
for HCV antibody confirmed by a supplemental test (or simply positive for HCV by the
supplemental test).
Descriptive epidemiology
• Number of cases in Illinois in 2007 – Sixteen cases of acute hepatitis C were
reported.
• Age – Acute hepatitis C cases ranged from 18 to 73 years of age (mean age = 42).
106
•
•
•
•
•
•
•
Gender – Forty-four percent of acute hepatitis C cases were male.
Race/ethnicity - For acute hepatitis C cases, 80 percent of cases were white and 20
percent were African American; No cases reported Hispanic ethnicity.
Seasonal variation – Cases were reported from January to November.
Geographic variation – Cases were reported from 10 counties.
Reporter – Sixty-two percent of cases were reported by hospitals and 38 percent by
private laboratories.
Risk factors - For acute hepatitis C, nine cases reported a history of injection drug
use.
Symptoms/outcomes – Fifty percent of 14 acute hepatitis C cases with histories
were hospitalized, and no cases were fatal.
Suggested readings
Daniels, D., et. al. Surveillance for acute viral hepatitis – United States, 2007.
MMWR 2009; 58 (SS-3): 1-27.
Labus, B., et.al. Acute hepatitis C virus infections attributed to unsafe injection
practices at an endoscopy clinic-Nevada, 2007. MMWR 2008;57(19):514-521.
Wang, C.C., et. al. Acute hepatitis C in a contemporary US cohort: Modes of
acquisition and factors influencing viral clearance. JID 2007;196:1474-82.
107
Hepatitis C, chronic or resolved
Background
The World Health Organization estimates that 170 million people worldwide are
infected with HCV. The hepatitis C virus can cause chronic hepatitis, cirrhosis and
hepatocellular carcinoma. Among adults who had acute hepatitis C, 26 percent to 50
percent developed chronic active hepatitis and 3 percent to 26 percent developed
cirrhosis. In a study of transfusion related hepatitis C in the United States from 1968
through 1980, the risk for developing cirrhosis was 17 percent. Heavy alcohol use
increased the risk for developing cirrhosis. Anti-HCV positive persons had a 5- to 50fold higher risk of primary hepatocellular carcinoma compared to anti-HCV negative
patients. These sequelae typically take 20 or more years to develop.
Hepatitis C is the most common indication for liver transplantation in adults and
accounts for about 40 percent of all transplants in the United States. About 50 percent
to 80 percent of patients with pretransplantation viremia develop hepatitis in the liver
graft.
Persons with chronic hepatitis C should not drink alcohol and should be
vaccinated for hepatitis A and hepatitis B. HCV-positive persons should not donate
blood, organs, tissues or semen. There is insufficient data to recommend that infected
persons change sexual practices with steady partners. HCV-positive household
members should not share toothbrushes or razors.
Treatment for hepatitis C may be recommended for persons with elevated serum
alanine aminotransferase (ALT) and tests that indicate the presence of circulating HCV
RNA. HCV RNA levels do not correlate with grade or stage of disease. HCV is divided
into six genotypes. Genotype is a predictor of response to therapy. Genotype 1a and 1b
HCV infection, the most common types in the United States, have a poorer response to
therapy than other types. Response to therapy is higher in those with genotypes 2 and
3.
Descriptive epidemiology
• Number of cases in Illinois in 2007 – There were 7,840 cases of chronic or resolved
hepatitis C reported. Because this is a chronic disease, these cases may have
acquired infection years ago and the number of cases is just the number of cases
reported in 2007, not necessarily the year of exposure or onset of any illness.
• Age – Chronic or resolved hepatitis C cases ranged from less than one year to 99
years of age (mean age = 50 years).
• Gender – Sixty-one percent of chronic or resolved hepatitis C cases were male.
• Race/ethnicity - For chronic or resolved hepatitis C cases, 70 percent of cases were
white, 25 percent were African American and 4 percent were other races; 6 percent
were Hispanic.
• Geographic variation – Reported cases resided in 100 of the 102 counties in Illinois.
The counties reported the highest incidence per 100,000 included Brown (388)
Pope (181), Massac (171), Johnson (163), Jefferson (157), Randolph (147) and
Saline (142). These are small population counties where small populations and
prison populations may elevate the incidence rates. Fourteen of the 27 Brown
108
•
•
•
County cases were reported by correctional facilities.The counties reporting the
most cases were Cook (3,777), Winnebago (307), Lake (303), Dupage (296), Will
(264) and St Clair (253).
Genotype – Genotype was only available for 172 cases. The most common
genotypes reported were 1a (86 cases), 1b (44), 2b (17) and 3a (nine). Genotypes
reported in five or less persons included 1a/1b, 2, 2a, 2a/2c, 2d, 1, 3, 3b, 3 and 4a.
Symptoms/outcomes – Of the 2,946 cases with information about hospitalization
status, 26 percent of cases were hospitalized. Five cases were fatal.
Reporter – Seventy-six percent of cases were reported by laboratories and 18
percent by hospital personnel other than laboratory.
109
Histoplasmosis
Background
Histoplasmosis is a systemic fungal disease caused by Histoplasma capsulatum.
Transmission occurs through inhalation of the organism. The incubation period ranges
from three to 17 days. Signs and symptoms of histoplasmosis include fever, headache,
muscle aches, cough and chest pain. Patients who have underlying lung disease may
develop chronic lung disease after H. capsulatum infection. Bird and bat droppings are
beneficial to the growth of the organism. Diagnosis of infection can be through culture
or serology. The M precipitin alone indicates active or past infection. The H precipitin
indicates active disease or recent infection.
Histoplasmosis can be a severe infection in persons with HIV or other
immunocompromising conditions. Approximately 5 percent of persons with AIDS who
live in endemic areas may develop histoplasmosis, which frequently disseminates.
Case definition
Histoplasmosis is not a nationally notifiable disease. The case definition for
histoplasmosis in Illinois is either:
1)
Isolation of the organism from a clinical specimen in patients with acute
onset of flu-like symptoms, or
2)
In patients with flu-like symptoms, hilar adenopathy and/or patchy
infiltrates found on chest radiograph, if done, and at least one of the
following
a.
M or H precipitin bands positive by immunodiffusion
b.
A four-fold rise between acute and convalescent complement
fixation (CF) titers
c.
A single CF titer of >1:32
d.
Demonstration of histoplasma polysaccharide antigen by
radioimmunoassay (RIA) in blood or urine, or demonstration of
organisms by silver staining blood specimens or biopsy material
A confirmed must be culture confirmed. A probable case is a clinically
compatible illness not culture confirmed but with one of the other
laboratory tests listed above positive.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 - 123 (five-year median = 96) (see
Figure 51). At least 22 (18 percent) of these cases were in immunocompromised
persons; therefore, it is not possible to determine whether they represent new
infections or reactivation of previous infections.
• Sex – Sixty-three percent of cases were male.
• Age – Ages ranged from two to 87 years (mean age was 42 years) (Figure 52).
• Race/ethnicity – Seventy-nine percent were white, 16 percent were African
Americans, and 5 percent were other races; 11 percent were Hispanic.
• Diagnosis - Thirty-two cases (26 percent) were confirmed by culture. Cultures were
positive from blood (nine), bone or bone marrow (three), sputum (one), bronchial
110
•
•
•
•
•
wash (six), lung tissue (six), other site (four) and unknown site (three). For those not
culture positive, the following test types were positive: serum (81), urine (eight) and
both urine and antigen (two).
Seasonal variation - No seasonal trend was identified (See Figure 53).
Geographic variation - The three counties reporting the most cases were Cook (20
cases), Champaign (11 cases) and Will (10 cases).
Outcomes – Sixty-eight (61 percent) of cases were hospitalized; three cases were
believe to have died due to histoplasmosis.
Outbreaks - One outbreak was reported in 2007. Four residents of Grundy county
traveled to Union county to hunt and became ill with histoplasmosis. A specific
source could not be identified.
Reporting- The most common reporters were laboratories (49 percent) and hospital
personnel (47 percent).
Summary
In 2007, 123 cases were reported as compared to 112 in 2006. One outbreak
was reported.
Figure 51. Histoplasmosis Cases in Illinois, 2002-2007
Number of
cases
150
98
100
112
96
123
72
57
50
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 52 . Age Distribution of Histoplasmosis Cases in Illinois, 2007
30
20
10
0
0-9 yr
10-19 yr
20-29 yr
30-39 yr
Age groups
111
40-49 yr
50-59 yr
>59
Number of cases
Figure 53. Histoplasmosis Cases in Illinois by Month, 2007
25
20
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Month of onset
112
Sep
Oct
Nov
Dec
Influenza, novel
Background
Novel influenza is reportable to monitor trends in influenza. Novel subtypes of
influenza include, but are not limited to, H2, H5, H7 or H9 or influenza H1 or H3
subtypes from a non human species or from genetic reassortment between animal and
human viruses. Novel infections were reported from three states in 2007 (Ohio, Illinois
and Michigan). Ill patients were infected with swine influenza viruses (swine H1N1 and
H1N2). The virus was a triple reassortment containing genes from swine, avian and
human viruses.
Descriptive Epidemiology
Number of cases reported in Illinois – One case was reported in 2007.
Individual case description
• A 48-year-old woman in Illinois was diagnosed with swine influenza (H1N1). The
patient had underlying disease-COPD. She had fever, chills and cyanosis on
August 22 and was hospitalized and intubated for respiratory distress on August
24. Viral culture was positive on August 31 and oseltamivir therapy was initiated.
She had traveled to a fair where swine were present but had not been near the
swine and the swine had shown no signs of illness.
113
Influenza-associated pediatric mortality (< 18 years)
Background
This category of influenza reporting is to monitor the effect of influenza on young
persons. Seventy-seven cases were reported in the United States from 27 states in
2007 (0.10 deaths per 100,000). The median age at death was seven years. Fortythree percent had one or more underlying conditions. Only 6 percent were fully
vaccinated. The ACIP recommends annual vaccination of all children aged 6 months to
18 years.
Descriptive epidemiology
Cases reported in Illinois – One death from influenza in those less than 18 years
were reported in Illinois.
Individual Case Description
• A 12-year-old Cook County resident developed fever, pneumonia, pulmonary
hemorrhage and acute respiratory distress syndrome in March. She had not
received an influenza vaccine that season. She tested positive for influenza type
B and CDC identified B/Victoria/2/87 lineage. She was put on mechanical
ventilation and started on Tamiflu. She also was culture positive for MRSA in
sputum. The case was fatal.
114
Legionellosis
Background
Legionella spp are a group of intracellular pathogens that often inhabit aquatic
environments where they can survive well. There are 48 species of Legionella and
several serotypes. L. pneumophila serotype 1 is responsible for most lower respiratory
tract infections. However, 19 other Legionella species have been documented as
human pathogens based on isolation from clinical material. The two major clinical
manifestations of infection with Legionella bacteria are Legionnaires’ disease
(legionellosis) and Pontiac fever. Legionellosis may be epidemic or sporadic,
nosocomial or community acquired. The incubation period is two to 10 days (average
five to six days). For Pontiac fever, it is five to 66 hours (average 24-48 hours). Initial
symptoms of both are anorexia, myalgia and headache often followed by a
nonproductive cough and diarrhea. Patients with legionellosis clinically have pneumonia
and abnormal chest radiographs.
Legionellosis most often occurs in those who are immunocompromised due to
disease or aging. Risk factors are underlying medical conditions such as human
immunodeficiency virus, organ transplantation, renal dialysis, diabetes, chronic
obstructive pulmonary disease, cancer, immunosuppressive medication or smoking.
Pontiac fever is an acute, febrile illness with a high attack rate, short incubation period
and rapid recovery. Most cases are sporadic (not associated with a known outbreak).
Outbreaks have been associated with aerosol producing devices such as whirlpool
spas, showers, humidifiers, respiratory care equipment, evaporative condensers, air
conditioners, grocery store mist machines and cooling towers and have occurred in
industrial settings. Approximately 20 percent of all Legionnaires’ disease cases are
associated with recent travel. Many are thought to be associated with potable water
systems in hotels or whirlpool spas in hotels or on board cruise ships.
Legionella urine antigen testing and culture of respiratory secretions are useful
for diagnostic testing. The urine antigen test provides rapid diagnosis for L.
pneumophila serogroup 1 but will not provide an isolate to compare to clinical and
environmental isolates gathered during outbreak investigations. Testing for Legionella
species is not performed by the Department laboratory. Most test results among
reported cases are from hospital or commercial laboratories.
In a study of legionellosis in Canada, male gender and advanced age were
associated with Legionella infection. Cases increased in summer and autumn months.
In 2007, 2,716 cases of legionellosis were reported to CDC from state health
departments. CDC has a travel-associated Legionella surveillance e-mail address used
by state health departments to report cases of Legionella that have traveled outside
their state.
Case definition
A confirmed case in Illinois is one that meets the CDC case definition, i.e., a
clinically compatible illness with laboratory confirmation of disease by 1) isolation of
Legionella from lung tissue, respiratory secretions, pleural fluid, blood or other normally
115
sterile sites; or 2) demonstration of a fourfold or greater rise in the reciprocal indirect
fluorescence (IF) antibody titer to greater than or equal to 128 against L. pneumophila
serogroup 1 between paired acute and convalescent phase serum specimens; or 3)
demonstration of L. pneumophila serogroup 1 in lung tissue, respiratory secretions, or
pleural fluid by direct fluorescent antibody (FA); or 4) demonstration of L. pneumophila
serogroup 1 antigens in urine by radioimmunoassay (RIA) or enzyme-linked
immunoassay (ELISA).
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – There were 111 cases reported (fiveyear median = 55). All cases were confirmed (Figure 54).
• Age - Ages ranged from 25 to 88 (mean age=61). Seventy-eight percent were
greater than 49 years of age (see Figure 55).
• Gender - Seventy-four (67 percent) cases were male.
• Race/ethnicity – Seventy-one percent of cases were white and 26 percent were
African American; 4 percent reported Hispanic ethnicity.
• Seasonal - An increase in cases occurred from June to September (Figure 56).
• Geographic distribution – Twenty-six counties reported cases. The two counties with
the most cases were Cook County (43 percent) and DuPage County (12 percent).
• Risk factors - Four cases were reported as residing in a residential facility.
• Diagnosis - Cases were diagnosed through urine antigen alone (93), serology alone
(one), culture alone (two), direct fluorescent antibody of lung biopsy alone (four) or
multiple tests (11).
• Outcomes - Hospitalization was required for 106 of 109 (97 percent) cases with
information available; Seven fatalities were attributed to reported legionellosis
infection.
• Reporting – Seventy-seven of 119 (70 percent) cases with information available
were reported by infection control professionals.
• Outbreaks – No outbreaks were reported in 2007.
Summary
In 2007, there was an increase in cases of legionellosis, as compared to the fiveyear median. There were no outbreaks of legionellosis reported in 2007.
Suggested readings
Ng, Victoria, et. al. Laboratory-based evaluation of legionellosis epidemiology in
Ontario, Canada, 1978 to 2006. BMC Infectious Diseases 2009; 9:68.
116
Number of cases
Figure 54. Legionellosis Cases in Illinois, 2002-2007
133
150
111
100
66
55
50
50
28
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 55. Age Distribution of Legionellosis Cases in Illinois, 2007
80
60
40
20
0
<30
30-39
40-49
50-59
>59
Age groups
Number of cases
Figure 56. Legionellosis Cases in Illinois by Month, 2007
40
30
20
10
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of onset
117
Aug
Sep
Oct
Nov
Dec
Lyme Disease
Background
Lyme disease is a tickborne zoonotic disease caused by the bacterium Borrelia
burgdorferi sensu lato. The reservoir is the black-legged tick (Ixodes scapularis),
commonly called the deer tick. Human disease is thought to be primarily caused by
nymphal tick bites, usually in late spring or summer. Babesiosis and ehrlichiosis also
are transmitted by the same tick. In the Midwest, wild rodents and other animals
maintain the transmission cycle. Deer are the preferred host of the adult tick.
Laboratory studies indicate ticks must be attached for at least 24 hours for
transmission to humans to occur. Experiments in animals have shown that most often
the tick must feed at least 48 hours before the risk of transmission becomes
substantial.
Lyme disease is characterized by a rash-like skin lesion called erythema migrans
(EM) that may be followed by cardiac, neurologic and/or rheumatologic involvement.
The incubation period for EM ranges from three to 32 days (mean: seven to 10 days)
after tick exposure; it is present in 80 percent to 90 percent of case patients. Erythema
migrans may be characterized by a homogenous rash rather than a target appearance
because of early presentation for treatment. EM is the most common clinical
manifestation of Lyme disease and resolves within about 28 days. Early manifestations
include fever, headache, fatigue, migratory arthralgias and possibly lymphadenopathy.
It can take approximately two to four weeks or longer for antibodies to be detected by
blood tests, so these tests are not required for patients diagnosed with EM in the public
health surveillance case definition.
There were 27,444 cases of Lyme disease (9.2 per 100,000) reported in 2007 in
the United States, mainly from the Northeast, mid-Atlantic and north-central regions of
the country. All but three states reported cases during 2007. Ten states - Connecticut,
Delaware, Maryland, Massachusetts, Minnesota, New Jersey, New York, Pennsylvania,
Rhode Island and Wisconsin - accounted for 87 percent of all cases reported.
Effective prevention measures include personal protective measures (tick
checks, repellents) and decreasing tick exposure. The Infectious Disease Society of
America has advanced the recommendation that antimicrobial prophylaxis can be
offered after a recognized tick bite if the following conditions are true: 1) the attached
tick is identified as Ixodes and was attached for greater than 36 hours, 2) Prophylaxis
can be started within two hours of when the tick was removed, 3) the tick infection rate
in the area is 20 percent or greater and 4) doxycycline is not contraindicated.
Case definition
The surveillance case definition for Lyme disease in Illinois is the CDC definition
for 2007: 1) erythema migrans, or 2) at least one late manifestation (musculoskeletal
system, nervous system or cardiovascular system) and supportive laboratory evidence
of infection or laboratory confirmation, i.e., isolation of B. burgdorferi from a clinical
specimen, or demonstration of diagnostic immunoglobulin M or immunoglobulin G
antibodies to B. burgdorferi in serum or cerebrospinal fluid (CSF). A two-test approach
118
using a sensitive enzyme immunoassay or immunofluorescence antibody followed by
Western blot is required by the Department for confirmation of non-EM cases.
Descriptive epidemiology
•
•
•
•
•
•
•
•
•
•
•
Number of cases reported in Illinois in 2007 – There were 149 (five-year median =
87) cases reported (See Figure 57). All cases were confirmed. The incidence was
1.2 per 100,000.
Age - Cases ranged in age from one to 83 years of age (mean= 36) (Figure 58).
Gender – Sixty percent were male.
Race/ethnicity – Of the 118 cases (98 percent) for which race is known, cases were
white; one case identified themselves as Hispanic.
Seasonal distribution – Lyme disease case onsets were most common from June
through July. (Figure 59).
Geographic distribution - Seventy-three cases reported a tick exposure within
Illinois, these are mapped in Figure 60. The regions where cases reported
exposures included the Rockford region (30 cases), West Chicago (13), Peoria
region (11), Bellwood region (six), Edwardsville region (five), Champaign region
(two) and Marion region (one). The counties most likely to be implicated as
exposure sites included Jo Daviess (10 cases) and Ogle (seven). Cases reported 23
Illinois counties as exposure sites. Five cases reported multiple Illinois regions as
exposure sites. Twelve cases reported exposures both in-state and out-of-state.
Fifty-seven cases reported non-Illinois exposure locations including Wisconsin (46),
New York (three), Massachusetts (two), Michigan (two), Indiana (one), Missouri
(one), Connecticut (one), Arkansas (one). Four persons reported exposures outside
of the country including Canada (two) and Poland (two). For three cases no
exposure location could be identified. There were thirty counties with residents
diagnosed with Lyme disease. The top six counties reporting residents with Lyme
disease included Cook County (30 cases), Dupage (16), Winnebago (11 cases),
JoDaviess (nine), Will (eight) and Lake (eight).
Tick distribution – A map of Illinois with the distribution of known Ixodes scapularis
(the vector for Lyme disease) is provided (Figure 61).
Symptoms - Qualifying manifestations were EM (129, 86 percent), rheumatologic
signs (11, 7 percent) and neurologic signs such as Bell’s palsy (eight, 5 percent). Six
percent of cases were hospitalized; no deaths were reported in cases.
Reporting – The three top reporters of Lyme disease cases were laboratory staff (63
percent), infection control professionals (17 percent) and clinics (16 percent).
Tick exposure – Forty-eight of 108 (44 percent) of cases reported a tick bite before
illness onset. One hundred thirty two of 139 (95 percent) of cases reported being in
a tick habitat. The three most common sites of tick exposure habitat were own
property (32 cases), parks and nature preserves (32 cases) and a campground (26
cases).
Past incidence - In Illinois, reported Lyme cases for previous years are as follows:
1991 (51), 1992 (41), 1993 (19), 1994 (24), 1995 (18), 1996 (10), 1997 (13), 1998
119
(14), 1999 (17), 2000 (35), 2001(32) and 2002 (47), 2003 (71) and 2004 (87), 2005
(127) and 2006 (110).
Summary
For the cases reported in Illinois residents during 2007, EM was the most
common qualifying manifestation for Lyme disease. The number of cases peaked in the
summer months. The out-of-state exposures occurred most commonly in Wisconsin.
The incidence in Illinois (1.2 per 100,000) is much lower than the national average (9.2
per 100,000) for 2007. The number of reported cases of Lyme disease increased over
2006.
Number of cases
Figure 57. Lyme Disease Cases in Illinois, 2002-2007
200
100
149
127
150
87
71
47
110
50
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 58. Age Distribution of Lyme Cases in Illinois, 2007
40
30
20
10
0
<10 yr
10-19 yr
20-29 yr
30-39
40-49
50-59
>59 yr
Age groups
Number of cases
Figure 59. Lyme Disease Cases in Illinois by Month, 2007
60
40
20
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of onset
120
Aug
Sep
Oct
Nov
Dec
Figure 60. Illinois Map of Reported Exposure Location of Lyme disease Cases by
County, 2007
121
Figure 61. Tick distribution map
122
Malaria
Background
Malaria is a very important global parasitic disease. It is endemic in more than
100 countries. The incubation period may range from seven days to 10 months.
Symptoms of malaria include fever, headache, muscle aches, fatigue, diarrhea and
vomiting. Four species of Plasmodium (P. vivax, P. falciparum, P. malariae and P.
ovale) cause disease in people. P. vivax malaria is the most common form. P.
falciparum is the most common species in tropical areas and causes the most malaria
deaths. The majority of malaria-endemic countries are in sub-Saharan Africa,
Southeast Asia and Latin America. More than 90 percent of the incidence of malaria in
the world occurs in sub-Saharan Africa and two-thirds of the remaining cases occur in
India, Myanmar, Afghanistan, Vietnam and Colombia. The highest risk of malaria is for
travelers to sub-Saharan Africa, Papua New Guinea and the Solomon Islands. About
90 percent of P. falciparum infections are acquired in Africa. More than 70 percent of P.
vivax infections are due to exposures in Asia or Latin America.
Immunity lasts less than two years once a person leaves an endemic area.
Many persons who travel back to their home country assume they are immune.
Identification of the species is important because treatment can differ. For example,
disease caused by P. falciparum has a more serious prognosis and must be treated
differently. Untreated P. falciparum can progress to coma, renal failure, pulmonary
edema and death. In a large study in Asia, mortality increased from 6 percent in
children less than 10 years of age to 36 percent in persons older than 50 years of age.
The majority of fatal cases in the United States are due to not using correct
chemoprophylaxis, incorrect initial chemotherapy and delays in malarial diagnosis. One
of the most important diagnoses to consider in recent travelers with fever is malaria.
Imported malaria cases occur in Illinois when someone with the disease immigrates to
the United States or when someone who travels overseas uses inadequate
chemoprophylaxis. Persons traveling to malarious areas should take recommended
chemoprophylaxis regimens and use appropriate personal protective measures against
mosquito bites (using mosquito nets at night when accommodations do not protect
against mosquitos and using repellents). The risk of malaria depends on geographic
location of travel, urban versus rural stay, type of accommodations, duration of stay,
time of the year, activities, elevation and compliance with preventive measures. In the
United States, malaria is transmitted predominantly by the bite of an infective female
anopheline mosquito in travelers while overseas. Other less common methods include
infected blood products, congenital transmission or local mosquito borne transmission.
Malarial infection or relapse during pregnancy results in risk to the mother and fetus,
including maternal anemia, spontaneous abortion, perinatal mortality, low birth weight,
and prematurity. Symptoms in newborns include fever, poor appetite, irritability, and
lethargy and can mimic sepsis.
Malaria should be considered in the differential diagnosis of illness in persons
with 1) fever and a history of travel to areas where malaria is endemic, including
immigrants, 2) fever of unknown origin, regardless of travel history, or in 3) ill neonates
123
and young infants with fever and mothers who have immigrated or traveled to areas
where malaria is endemic. A new rapid diagnostic test for malaria was approved by
FDA in June 2007. All rapid tests should be followed by microscopy to confirm.
The majority of malaria infections in Illinois are caused by travel to areas with
ongoing transmission. In 2007, 1,505 malaria cases were reported in the United States
including one fatal case. The species of malaria identified in these cases was
falciparum (43 percent), vivax (20 percent), malariae (2 percent) and ovale (3.5
percent). In 30 percent of cases the species was unknown. Malaria is transmitted in
parts of Africa, Asia, the Middle East, Central and South America, the island of
Hispaniola and Oceania. The majority of infections in the United States were acquired
in Africa (64 percent), followed by Asia (22 percent), the Americas (11 percent) and
Oceania (2 percent). Twenty-six percent of the cases who took an antimalarial drug did
not take a CDC recommended drug for the region they were visiting. Of the 143
patients who contracted malaria after taking a recommended antimalarial drug for
chemoprophylaxis, 30 percent reported compliance with the regimen, 59 percent
reported noncompliance and 10 percent had missing compliance information. For P.
vivax or P. ovale, if onset develops 45 days after arriving in the United States, this is
consistent with relapsing infections and does not indicate primary prophylaxis failure.
Of the United States civilians with malaria, 63 percent of persons had visited friends or
relatives in malarious areas. The second leading reason for travel was tourism (10
percent), followed by missionary work (8 percent).
Case definition
Illinois uses the CDC case definition. A confirmed case is a person
(symptomatic or asymptomatic) with an episode of microscopically confirmed malaria
parasitemia diagnosed in the United States, regardless of whether the person
experienced previous episodes of malaria while outside the country.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – There were 63 cases reported
(five-year median = 61) (see Figure 62). All were confirmed cases.
• Age – Forty-eight percent of cases occurred in persons from 10 to 39 years of
age. The mean age was 30. (Figure 63)
• Sex – Sixty-five percent were male.
• Race/ethnicity – Fifty-six percent were African American, 14 percent were white,
19 percent were Asian and 10 percent were other races; no cases were reported
to be of Hispanic ethnicity. There were significantly higher proportions of African
Americans and Asians with malaria compared to their presence in the Illinois
population and significantly lower proportions of whites and Hispanics with
malaria compared to the Illinois population.
• Geographic location – Malaria cases were reported from 14 counties. The
majority were reported from Cook County (49 percent).
• Seasonal variation - Cases of malaria were reported in greater numbers in
124
•
•
January (Figure 64).
Speciation - The malaria species identified in the reported cases were P.
falciparum (38 cases, 61 percent of cases with known species), P. vivax (18
cases, 45 percent), P. malariae (two cases, 3 percent), P. ovale (four cases, 6
percent) and unknown (one case).
Treatment/outcomes – Thirty-six of 58 cases (62 percent) were hospitalized.
One person died with malaria but it is unknown if malaria was the cause of
death. No cases of cerebral malaria were reported.
o The P. falciparum cases were treated with the following medications:
malarone (eight cases); quinine (one); doxycycline or tetracycline (one);
tetracycline or doxycycline and quinine (three), mefloquin, chloroquin and
tetracycline or doxycycline (one); chloroquin and tetracycline or
doxycycline (one), quinine, malarone and doxycycline or tetracycline
(one); quinine and tetracycline or doxycycline (one) and unknown (21).
o The P. vivax cases were treated with the following medications: mefloquin
(three), malarone (one); primaquin and mefloquin (two); primaquine and
chloroquin (three); primaquin and doxycycline or tetracycline (one);
mefloquin and tetracycline or doxycycline (one) and malarone and
hydroxychloroquin (one). Treatment type for six cases was unknown.
o The P. ovale cases were treated with the following medications: malarone
(one); primaquin and tetracycline or doxycycline (one); and tetracycline or
doxycycline (one). One case had unknown treatment medications.
o The P. malariae were treated with the following medications: mefloquin
(one case) and unknown (one).
•
•
Risk factors - The major risk factor for infection is travel outside the United
States. Specific information was available for 55 of the 2007 cases. The Asian
countries reported by 17 cases as travel destinations were India (12 cases),
Papua New Guinea (two cases), Thailand (two cases) and Burma (one case). In
Africa, the following travel destinations were reported for 35 cases: Nigeria (19
cases), Tanzania (five cases), Ghana (three cases), Uganda (two cases), Liberia
(one case), Ivory Coast (one case), Africa, not further specified (two) and
multiple African countries (two cases). No cases reported a travel destination of
South America. One case reported travel to the Middle East (Afghanistan). Two
cases reported travel destinations in multiple continents. For eight persons,
travel history was unknown.
Of the 19 cases reporting travel to Nigeria, all were infected with P. falciparum.
Of the five cases reporting travel to Tanzania, four were falciparum and one had
an unknown species. Of the three cases who visited Ghana, two had P.
125
•
•
•
•
falciparum and one case had P. ovale. Of the 12 cases reporting travel to India,
11 were infected with P. vivax and one with P. falciparum.
Cases provided the following reasons for travel overseas: visiting friends or
relatives (17), immigrant (10), business (five), tourism (four), missionary work
(three), adoption (two), student/teacher (two), military (one) and unknown (19).
Malaria prophylaxis was reported by only 19 of 39 cases providing information
(49 percent). Nine persons reporting taking prophylaxis correctly, eight said they
missed doses and for two this information was unknown. Cases indicated taking
the following medications for the prevention of malaria: malarone (four),
mefloquin (three), sulfadoxine/ pyrimethamine (three), doxycycline (two),
chloroquin (two), primaquin (two) and unknown medication (three).
Reporting – Forty-five of 63 cases (71 percent) were reported by hospitals and
16 of 63 (25 percent) were reported by laboratories. Other reporters reported 4
percent of malaria cases.
Past infection – Twenty-nine cases reported no previous history of malaria and
seven cases reported a previous history of malaria. Information on past history of
malaria was not completed for 27 cases.
Summary
There were 63 reported cases of imported malaria identified in Illinois in 2007,
the 7th highest number of cases among the states. This was similar to the median (61
cases) for the previous five years.
African Americans and Asians made up a higher proportion of persons with
malaria than in the Illinois population. Laboratories should forward blood smears to the
Department’s laboratory for verification of species. Laboratories should be thorough in
identifying the species of this parasite because treatment differs by species (e.g., P.
vivax and P. ovale require additional treatment with primaquine to prevent relapses)
and simultaneous infection with more than one species does occur.
Suggested readings
Dondrop, A.M., et. al. The relationship between age and the manifestations of
and mortality associated with severe malaria. CID 2008;47:151-7.
Mali, S., et. al., Malaria Surveillance – United States, 2007. MMWR 2009; 58(S
S02); 1-16.
126
Number of cases
Figure 62. Malaria Cases in Illinois, 2002-2007
100
80
60
40
20
0
83
74
63
61
47
46
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 63. Age Distribution of Malaria Cases in Illinois, 2007
25
20
15
10
5
0
<1 yr
1-4 yr
5- 9 yr
1 0-19 yr
20-29 yr
30-39 yr
40-4 9 yr
50 -59 yr
>59 yr
Age Group
Number of cases
Figure 64. Malaria Cases in Illinois by Month, 2007
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Onset
127
Aug
Sep
Oct
Nov
Dec
Measles
Background
Measles is a highly communicable viral disease with humans as the only natural
host for the infection. Transmission most commonly occurs through airborne spread or
through direct contact with nasal or throat secretions of infected people. The incubation
period is about 10 days, but varies from seven to 18 days. Infected individuals show
fever, conjunctivitis, coryza, cough and Koplik’s spots on the buccal mucosa, along with
a rash that appears on the third to seventh day. The disease can be prevented by
proper immunizations. A two-dose vaccination schedule is recommended in the United
States, one at 12 to 15 months and one at school entry (four to six years) or by 11 to 12
years. Sustaining high levels of vaccination is important to limit indigenous spread of
measles from cases imported into the United States.
Nationally, there were 43 cases reported to CDC; Twenty-nine were
internationally imported and 12 additional cases occurred from these imported cases.
For two cases, the source was classified as unknown because no link to importation
could be identified. Four outbreaks occurred, all from imported sources.
Case definition
A confirmed case in Illinois is one that meets the CDC definition, i.e., a case that
is laboratory confirmed, or that meets the clinical case definition and is
epidemiologically linked to a confirmed case. Laboratory confirmation consists of 1)
isolation of measles virus from a clinical specimen, or 2) significant rise in measles
antibody level by any standard serologic assay, or 3) positive serologic test for measles
IgM antibody. The clinical case definition is an illness characterized by a generalized
rash lasting at least three days, and a temperature of at least 101° F, and a cough or
coryza or conjunctivitis. A probable case meets the clinical case definition, has
noncontributory or no serologic or virologic testing, and is not epidemiologically linked to
a confirmed case.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – One case of measles was reported
in 2007 (five-year median=one case) (Figure 65).
• Case description – A 53-year-old health care worker who had traveled to Ghana
on a medical mission developed onset of illness in late September. Symptoms
included fever, rash, cough and Koplik’s spots. Diagnosis was by serology at
CDC. The vaccination history was unknown.
Summary
One case of measles was reported.
128
Number of cases
Figure 65. Measles Cases in Illinois, 2002-2007
2.5
2
1.5
1
0.5
0
2
1
1
1
1
0
2002
2003
2004
2005
Year
129
2006
2007
Mumps
Background
Mumps is transmitted by droplet spread and by direct contact with the saliva of
an infected person. The incubation period is 12 to 25 days. This viral disease is
characterized by fever, headache, lethargy and swelling and tenderness of salivary
glands lasting two or more days and without other apparent cause. Orchitis may occur
in males and oophoritis in females. Before vaccination was available mumps was the
leading cause of viral meningitis and unilateral acquired deafness in children. Winter
and spring are the times of increased occurrence. Vaccination can prevent mumps. To
prevent mumps a two-dose MMR vaccination series for all children (first dose at 12-15
months, second dose at 4-6 years of age) is recommended. Two doses are
recommended for school and college entry unless there is other evidence of immunity.
In the five-day period after onset of parotitis, isolation is recommended in both the
community setting or the health care setting and standard droplet precautions are
recommended. In 2007, 800 mumps cases were reported to CDC. Outbreaks can occur
in highly vaccinated populations.
Case definition
A confirmed case in Illinois is one that meets the CDC case definition: a clinically
compatible illness that is laboratory confirmed, or that meets the clinical case definition
and is epidemiologically linked to a confirmed or probable case. A laboratory-confirmed
case does not need to meet the clinical case definition. The laboratory confirmation
may consist of 1) isolation of mumps virus from a clinical specimen, or 2) a significant
rise in mumps antibody level by a standard serologic assay, or 3) a positive serologic
test for mumps IgM antibody. The clinical case definition is an illness with acute onset
of unilateral or bilateral tender, self-limiting swelling of the parotid or other salivary
gland, lasting more than two days, and without other apparent cause.
Descriptive epidemiology
•
•
•
•
•
•
•
•
Number of cases reported in Illinois in 2007 – There were 170 cases reported (fiveyear median = 10) (Figure 66). Of the 170 cases, 74 were confirmed and 96 were
probable.
Age - Mean age was 23 years (range was two years to 79 years) (Figure 67).
Gender - Fifty-one percent were female.
Race/ethnicity - Eighty percent were white, 9 percent were African American, 3
percent were Asian and 8 percent were other. Twenty-two percent reported
Hispanic ethnicity.
Geographic distribution - Cases resided in 26 counties. Counties with the most
cases included Cook (53), Kane (35), Dupage (13) and Dekalb (12).
Seasonal variation - Cases increased from January through March (Figure 68).
Clinical syndrome – The mean duration of parotitis was seven days.
Outcome – Complications included orchitis (seven cases). Five cases were
130
•
admitted to the hospital. No fatalities were reported.
Immunization status – Of the 170 cases reported in Illinois, 52 percent reported a
history of two doses of mumps-containing vaccine, 10 percent had one dose and
an additional 10 percent had an unsubstantiated number of mumps-containing
doses. Twenty-six percent had unknown vaccination status or had not been
vaccinated.
Summary
Of the states in the United States, Illinois reported the highest number of mumps
cases in 2007. The mean age of the 170 reported mumps cases in 2007 was 23 years.
There was a decrease in mumps cases over the number of cases reported in 2006.
Suggested readings
Anon. Updated recommendations for isolation of persons with mumps. MMWR
2008; 57(40): 1103-5.
Dayan, G.H. and Rubin, S. Mumps outbreaks in vaccinated populations: Are
available mumps vaccines effective enough to prevent outbreaks? CID 2008;47:145867.
Number of cases
Figure 66 . Mumps Cases in Illinois, 2002-2007
1000
800
600
400
200
0
798
170
18
8
2002
10
2003
10
2004
2005
Year
131
2006
2007
Number of cases
Figure 67. Age Distribution of Mumps Cases in Illinois, 2007
80
60
40
20
0
<1 yr
1-4 yr
5- 9 yr
1 0-19 yr
20-29 yr
30-39 yr
40-4 9 yr
50 -59 yr
>59 yr
Age Group
Number of cases
Figure 68. Mumps Cases in Illinois by Month, 2007
40
30
20
10
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Onset
132
Aug
Sep
Oct
Nov
Dec
Pertussis
Background
Pertussis is a highly infectious respiratory disease and is caused by Bordatella
pertussis and is characterized by a paroxysmal cough that can last several weeks.
Pertussis should be considered in adolescents and adults especially if the cough is
associated with vomiting or gagging or persists more than two weeks. Pertussis in
adults may be missed because symptoms may be atypical, and nasopharyngeal
cultures are rarely positive if taken during the first seven days of illness. Pertussis is
transmitted from person to person via aerosolized droplets from cough or sneeze or by
direct contact with secretions from the respiratory tract of infectious persons. Pertussis
can be highly infectious during the three weeks after onset of illness. The incubation
period is usually seven to 10 days although it can range from six to 20 days. A
resurgence of cases has been reported in the last decade in the United States.
A total of 10,454 pertussis cases (3.6 per 100,000) were reported to CDC from
states in 2007. The likely explanation for the high numbers of cases reported include
increased circulation of B. pertussis, waning vaccine-induced immunity among
adolescents and adults, increased reporting and increased use of PCR testing. Of
these cases, the incidence was highest (70 per 100,000 population) in infants younger
than 6 months of age (too young to have received three doses of vaccine). Vaccineinduced immunity wanes about five to 10 years after pertussis vaccination.
For the first week, mild fever, coryza and cough are common. From week one
through six, a paroxysmal cough, inspiratory whoop, and post-tussive vomiting may
occur. From six to 12 weeks, the intensity of cough decreases. Outbreaks are
managed through prompt treatment of patients and antimicrobial prophylaxis of close
contacts. Acellular pertussis vaccines are used in children from 6 weeks to 6 years of
age.
Pertussis has increased in adults. Active immunization with five doses of vaccine
at 2, 4, and 6 months of age, at 12 to15 months and at school entry can prevent this
disease. However, immunity from childhood vaccination decreases beginning five to 15
years after the last pertussis vaccine dose. Vaccination with Tdap vaccine of persons
aged 11 to 64 is recommended.
To confirm the diagnosis of pertussis in symptomatic adults, physicians should
obtain a nasopharyngeal aspirate or swab for B. pertussis culture within two weeks of
cough onset. The lack of fast, sensitive and specific tests makes laboratory diagnosis
difficult. In outbreak settings, positive PCR should be interpreted in conjunction with
epidemiologic investigation, clinical course and confirmed by culture. A subset of cases
should be cultured. Culture is the gold standard and 100 percent specific. Its sensitivity
can be up to 56 percent early in the course of illness but decreases with delays in
specimen collection, in vaccinated patients or patients treated with antimicrobials.
Isolation of the organism can take seven to 14 days.
Case definition
The case definition for pertussis in Illinois is a clinically compatible illness that is
133
laboratory confirmed or epidemiologically linked to a laboratory-confirmed case.
Laboratory confirmation is through culture of B. pertussis from a clinical specimen. A
clinically compatible illness is a cough lasting at least two weeks with one of the
following: paroxysms of coughing, inspiratory whoop or post-tussive vomiting (without
other apparent causes) or greater than two weeks of cough in a person in an outbreak
setting. A confirmed case is defined as a cough illness of any duration in any person
with isolation of B. pertussis or a case that meets the clinical case definition and is
confirmed by polymerase chain reaction or by epidemiologic linkage to a laboratoryconfirmed case. A probable case meets the clinical case definition but is not laboratory
confirmed or epidemiologically linked to a laboratory-confirmed case.
Descriptive epidemiology
•
•
•
•
•
•
•
•
•
Number of cases reported in Illinois in 2007 – There were 199 cases reported (fiveyear median = 588) (Figure 69). Of the 199 cases, 140 were confirmed and 59
were probable. The one-year incidence rate for pertussis was 1.6 per 100,000.
Age – Twenty-eight percent occurred in those younger than 5 years of age (Figure
70). In 2007, 67 of 198 reported cases (34 percent) occurred in those over 19 years
of age.
Gender - Females comprised 57 percent of cases.
Race/ethnicity – Eighty-seven percent were white, 6 percent were African
American, 7 percent were in other races and 26 cases were of unknown race; 11
percent reported Hispanic ethnicity.
Geographic location – Cases were identified from 38 counties. Counties reporting
the most cases included Cook (81), Lake (19) and Will (12).
Seasonal variation - Cases were highest in January (Figure 71).
Clinical syndrome – All cases reported cough and 158 cases reported paroxysmal
cough. Sixty-two cases reported a whoop. Fifty-seven cases reported apnea and
83 cases reported post-tussive vomiting.
Previous Vaccination – Ninety-five cases reported receiving at least one pertussis
vaccination. Thirty-six cases reported never having received a pertussis
vaccination.
Outcome – Forty-four cases were hospitalized. No cases were fatal.
Summary
The number of yearly reported pertussis cases decreased since 2006 in Illinois.
The incidence in Illinois was lower (1.6 per 100,000) as compared to 3.6 per 100,000
nationally. There were 199 pertussis cases reported in Illinois in 2007. Adolescent and
adult pertussis cases have increased in Illinois, and this follows a national trend in
2007.
134
Number of cases
Figure 69. Pertussis Cases in Illinois, 2002-2007
2000
1554
1500
922
1000
500
588
321
231
199
0
2002
2003
2004
2005
2006
2007
Year
Incidence of c ases
Figure 70. Age Distribution of Pertussis Cases in Illinois, 2007
30
20
10
0
<1 yr
1-4 yr
5-9 yr
1 0-19 yr
>19 years
Yea r
Number of cases
Figure 71. Pertussis Cases in Illinois by Month, 2007
50
40
30
20
10
0
Jan
Feb
Mar
Apr
May
Jun
Year
135
Jul
Aug
Sep
Oct
Nov
Dec
Q fever
Background
Q fever is an acute rickettsial disease found worldwide. Coxiella burnetti is the
causative agent. Phase I is found in nature and phase II after multiple laboratory
passages in the laboratory. The infective dose can be very low, as low as one
organism. The diagnosis of Q fever relies on serologic testing. In 60 percent of cases,
acute Q fever can be asymptomatic. In patients with acute Q fever, it is usually mild and
sometimes complicated by febrile illness, pneumonia or hepatitis infection.
Chronic Q fever develops in patients predisposed to the disease and includes those
who are immunosuppressed or who have valvulopathies. In a study in France, the
median time to diagnosis of chronic Q fever was three months after experiencing acute
Q fever. Persons at higher risk of Q fever infection include animal workers. The animal
reservoirs include sheep, cattle, goats, cats, dogs, and some wild animals. The
organism can be shed in high quantities in placental fluids at parturition. Ticks can be a
rare source of infection in the United States. Q fever is most commonly transmitted
through airborne dissemination of the organism in dust from premises contaminated
with placental tissues and excreta of infected animals, in necropsy rooms or in animal
processing establishments. Rarely, it can be transmitted from consumption of
unpasteurized milk or cheese. The incubation period is from two to three weeks. Q
fever is also a Category B bioterrorism agent. Outbreaks have been linked to aerosol
transmission in heavy winds.
In 2007, 171 cases of Q fever were reported to CDC. Illinois was third in the
nation in the number of reported cases.
Case definition
A confirmed case of Q fever is a clinically compatible illness with either isolation
of C. burnetti from a clinical specimen, demonstration of C. burnetti in a clinical
specimen by detection of antigen or nucleic acid, or a fourfold or greater change in
serum antibody titer to C. burnetti antigen. A probable case is defined as a clinically
compatible or epidemiologically linked case with an elevated serum antibody titer to C.
burnetti.
Descriptive epidemiology
•
Number of cases reported in Illinois in 2007 – There were 14 cases reported. All
were probable cases.
•
•
•
Age - Cases ranged in age from 26 to 86 (mean = 46 years of age).
Gender - Females comprised 36 percent of cases.
Race/ethnicity – Ninety-two percent were white and 8 percent were African
American. Two cases had unknown race; None reported Hispanic ethnicity.
Seasonal variation - Cases reported onsets from February through December.
Hospitalization – Four of 14 cases (28 percent) were hospitalized. No fatalities
were reported.
•
•
136
•
•
•
•
Reporting - Seventy-one percent of cases were reported by laboratories.
Geographic location – Eleven counties reported cases. Counties reporting
multiple cases included Adams (two), Cook (two) and Stephenson (two).
Risk factors – Six cases reported exposure to cattle, sheep and/or goats. One
case reported consuming unpasteurized dairy products.
Outbreaks – One outbreak of Q fever was reported in 2007. Further information
is available in the nonfoodborne and nonwaterborne outbreak section.
Summary
Fourteen cases of Q fever were reported in Illinois. One outbreak was reported in
Illinois. States reporting the highest number of cases were California (20), Colorado
(19), Illinois (14), New Mexico (12), Missouri (12) and Texas (11).
Suggested readings
Landais, C., et.al. From acute Q fever to endocarditis: Serological follow-up
strategy. CID 2007’44:1337-40.
137
Rabies
Background
In the United States, rabies is a disease that affects primarily wildlife populations.
It is a neurologic illness that follows infection with a rhabdovirus. It produces
encephalitis and typically progresses to death. Transmission of rabies to humans results
from the bite of a rabid animal or from contact between the saliva of a rabid animal and
a mucous membrane or wound. The rabies virus is inactivated by sunlight, heat and
desiccation.
The incubation period is usually three to eight weeks. Symptoms may include
fever, anxiety, malaise, and tingling and pruritus at the bite site. Neurologic signs,
beginning two to 10 days later, may include hyperactivity, paralysis, agitation, confusion,
hypersalivation and convulsions.The paralytic form of rabies must be differentiated from
Guillain Barré syndrome. After two to 12 days, the patient may go into a coma and
experience respiratory failure. Rabies should be considered in the differential diagnosis
of any acute rapidly progressive encephalitis, regardless of documentation of an animal
bite.
In 2007, the United States and Puerto Rico reported one case of human rabies
and 7,258 cases of animal rabies. Wild animals accounted for 93 percent of the animal
cases reported in the United States; the top three species with rabies were the raccoon,
bat and skunk. The top six rabies-positive bats after speciation (not done in all states)
were the big brown bat (68 percent), Mexican free-tailed bat (9 percent), Western
pipistrelle (6 percent), little brown bat (4 percent), the hoary bat (2 percent) and red bat
(3 percent). The most commonly identified rabid bat in the United States was the big
brown bat. The peak of bat rabies in the United States occurred in August.
In a study in Texas, skunk rabies had a 20-year cycle. The highest number of
skunks were from identified from March to April. Most of the domestic animals exposed
to rabid skunks were dogs and cats. Oral rabies vaccines have not been as effective in
skunks as other species because of low acceptance rates.
One 46-year-old developed rabies in the United States in 2007. In October 2007,
a Minnesota resident died of rabies after an incubation period of approximately one
month. This patient had handled a bat with his bare hands and felt a needle prick
sensation before releasing the bat. The patient assumed he had not been bitten and did
not seek medical attention. Rabies antibodies were detected in CSF and serum but the
rabies virus variant could not be identified. Three family contacts and 51 health care
providers received rabies PEP.
From 2000-2007, 25 human rabies cases were reported in the United States.
Eighteen (28 percent) were associated with suspected exposure to rabid bats or
infection with bat rabies virus variants. Most case occurred in late summer or early
autumn. In Asia and Africa, it is estimated that over 55,000 people die of rabies each
year.
Over the past 40 years in Illinois, skunks and bats have been the main wildlife
reservoirs of rabies virus. The last human case of rabies in Illinois was reported in 1954.
137
Case definition
The case definition for human rabies is a clinically compatible illness that is
laboratory confirmed. Laboratory confirmation is through detection by direct fluorescent
antibody (DFA) of viral antigens in a clinical specimen (preferably brain tissue or punch
biopsy of the nape of neck, including at least 10 hair follicles where associated nerves
are likely to show evidence of infection), or isolation of rabies virus from saliva or
cerebrospinal fluid (CSF), or identification of a rabies-neutralizing titer of greater than
1:5 in the serum or CSF of an unvaccinated person.
A case of animal rabies is confirmed by DFA of brain tissue. If samples are sent
to CDC, as is normally done only for confirmation of a positive result in a domestic
species, the CDC results are used as the final results for the purposes of this report.
Descriptive epidemiology
Number of animals submitted for rabies testing in Illinois in 2007 – 5,248; sixty-five
additional heads did not meet criteria established by the testing laboratories (Illinois
departments of Agriculture and Public Health). Examples of unsatisfactory specimens
are those determined to be too decomposed or too damaged to test. Of those
specimens submitted, 113 specimens were DFA positive; all were bats (Table 6).
Trends in animal rabies testing in Illinois are shown in Figure 72.
• Exposures to rabid bats - There were 113 rabid bat situations.
o In 69 of the 113 rabid bat situations, no human exposures sufficient to
require rabies PEP (per ACIP guidelines) occurred (for eight situations,
the human exposure information was unknown at the time of this report).
In 61 situations, bats were found inside homes. In 39 situations the bat
was found alive outside in yards, pools or near barns, and in 13 situations
the location of where the bat was found was unknown.
o Domestic animals (all dogs or cats) were either exposed or possibly
exposed in 22 situations (Table 7).
• Testing of bats - Bats accounted for all of the confirmed rabid animals in 2007.
The total number of bats tested for rabies was 2,102 (positivity rate = 5.38
percent).
o Geographic distribution - Rabid bats were dispersed in 76 counties across
the state. The following counties had rabid bats: Champaign (two), Clinton
(one), Cook (27), DuPage (two), Effingham (one), Franklin (one), Grundy
(one), Jackson (one), Kane (five), Lake (nine), LaSalle (two), Lee (four),
Logan (one), Madison (five), Marion (one), Massac (one), McHenry (13),
McLean (two), Mercer (one), Moultrie (one), Peoria (one), Sangamon
(five), Tazewell (two), Warren (two), Whiteside (three), Will (11),
Williamson (two), Winnebago (six) (Figure 73).
 Speciation - The Illinois Natural History Survey speciates bats
tested for rabies in Illinois. In 2007, 2,098 bats tested for rabies
were speciated (Table 8). There were 110 positive bats speciated
including the big brown bat (87), eastern red bat (14), hoary bat
(three), silver-haired bat (three), eastern pipistrelle (one), northern
long-eared bat (one) and little brown bat (one). Of the negative bats
138
speciated, the following results were found: big brown bat (1,436),
silver-haired bat (270), eastern red bat (154), little brown bat (45),
northern long-eared bat (39), hoary bat (20), eastern pipistrelle
(nine), evening bat (10) and not further identified/unknown (five).
o Seasonal variation - Figure 74 shows bats submitted for testing by month
in 2007. Bats submitted for rabies testing increase in August and
September.
•
Testing of skunks - Rabies testing was performed on 134 skunks in 2007 as
compared to 125 in 2006. At least one skunk from each of 27 Illinois counties
was tested; no skunks were tested in 75 counties. The following counties
submitted more than five skunks for rabies testing: Cook (13 skunks tested),
Dupage (26), Lake (19), McHenry (12), McLean (12), Will (14) and Jackson (six).
For rabies surveillance to be optimal in Illinois an adequate number of skunks,
the main terrestrial animal reservoir, must be tested. Test results from wild
terrestrial mammals is one factor used to determine whether rabies PEP is
recommended in cases of stray dog and cat bites. If enough skunks from
throughout the state are not tested, recommendations against rabies PEP
following such a bite cannot be made with confidence.
Figure 75 shows the number of rabid skunks found in Illinois and the road kill
index from 1975 through 2007. The road kill index is calculated by the Illinois
Department of Natural Resources as a measure of changes in the skunk
population size. When the road kill index increases, the skunk population is
increasing, and conditions are likely to be suitable for a rabies epizootic in
skunks. This last occurred in the late 1970s and early 1980s, when the road kill
index and the rate of skunks testing positive both increased.
•
•
Rabies positivity rate - Table 9 shows the rabies positivity rate in different species
of animals in Illinois from 1971 to 2007. This information can be useful in
explaining why rabies PEP is not recommended for the large majority of mouse,
rat and squirrel bites. No rats, mice or squirrels have been identified with rabies
in Illinois in more than 30 years. Because bats with rabies are identified almost
every year in Illinois, rabies PEP is recommended for exposures to these animals
and many other wild mammals unless they can be tested and are negative for
rabies. When comparing the positivity rates for cumulative 1971-2007 data vs.
1991-2007 data, the percentage of skunks positive for rabies declined
dramatically, and the percentage of positive bats stayed very constant.
Other rabies issues - The McLean CHD assisted in arranging for doses needed
for rabies PEP of several softball teams participating in a tournament in McLean
County. The teams had been exposed to a rabid kitten in South Carolina during a
softball tournament there.
Summary
Bats were the main species identified with rabies in Illinois in 2007. Illinois was
139
one of six states reporting rabies in bats but not in terrestrial animals. Testing of skunks
for rabies has declined in Illinois, thereby decreasing the reliability of surveillance of the
terrestrial animal reservoir in the state. Local animal control jurisdictions are encouraged
to increase submission of skunks for rabies testing to maintain surveillance in this
species.
Suggested readings
Bretous, L.M. et. al. Public health response to a rabid kitten-Four states, 2007.
MMWR 2008;56(51-52):1337-1340.
NASPHV. Compendium of Animal Rabies Prevention and Control. MMWR
2007;56(RR-3): 1-8.
Oertli, E.H., et. al. Epidemiology of rabies in skunks in Texas. JAVMA
2009;234(5):616-620.
Yee AH et al. Human rabies-Minnesota, 2007. MMWR 2008;57(17):460-2.
2500
2000
1500
1000
500
0
Year
140
20
06
20
04
20
02
20
00
19
98
19
96
19
94
# skunks tested
# bats tested
19
92
19
90
Number of
animals tested
Figure 72. Trends in Animal Rabies Testing in Illinois,
1990-2007
Table 6. Animal Rabies Testing in Illinois in 2007
Species
Total number suitable for testing
Total
positive
Bat
2,102
113
5.4
Cat
990
0
0
Cattle/buffalo
56
0
0
1,500
0
0
Coyote/fox/wolf
10
0
0
Ferret
6
0
0
Horse/donkey
Opossum
29
0
0
23
0
0
Raccoon
124
0
0
Rodents/lagomorphs
154
0
0
Sheep/goats
13
0
0
Skunk
134
0
0
Other*
42
0
0
TOTAL
5,183
113
2.2
Dog
%
positive
*”Other” species tested in 2007 included alpaca, coatimundi, deer, elk, mink, kangaroo,
shrew and zebra.
141
Table 7. Type of Exposure to Rabid Bats by Month, Illinois, 2007
Lab
number
Date
(2007)
County
Location where bat
found
Human exposure?
Animal exposure?
218643
2/8
Cook (Tinley Park)
None
None
218644
4/2
Whiteside (Fulton)
In house; caught with
towel
Bat in church
Unknown
218645
4/16
218655
218656
5/10
5/10
Sangamon
(Springfield)
Moultrie (Sullivan)
Lake (Lake Villa)
Yes, 1 person bitten
while collecting bat
None
Yes, 1 person bitten
None
Unknown
None
218657
218655
5/10
5/14
None
None
Unknown
None
218659
5/16
Logan (Lincoln)
Sangamon
(Springfield)
Warren (Monmouth)
Bat in house
Found in/near garage;
fell onto ground as door
raised
Unknown
Found in house on wall
Found dead on stairs
None
218660
5/20
Marion (Salem)
Yes, 1
218661
5/20
None
Yes, 1 dog
218662
5/22
Winnebago
(Rockford)
Champaign (Urbana)
Tried to pick up bat with
bare hand
Bat found with dog
outside
Woke to find bat in room
Yes, 1 cat locked in attic
for a week
None
None
218663
218646
5/22
5/24
Yes, 1; completed
series
None
Yes, 1
218647
5/30
None
Yes, 3 cats (2
vaccinated, 1
Franklin (Benton)
Cook (Arlington
Heights)
LaSalle (Earlville)
Bat in house
Found in park
Found in bedroom
Bat in house in cat’s
mouth
142
None
None
None
Bat in tree
Bat in basement
None
None
unvaccinated)
None
None
Bat in bedroom shortly
after she woke up
Bat flying in house
Yes, 2
Unknown
None
None
Bat outside in bushes;
cat caught it
Found dead in yard
Found in bedroom
Unknown
Found outside in tree
Found in child’s
bedroom
Found under stairs in
basement
Found in bedroom
None
Yes, 1 cat
None
Yes, 3
None
None
Yes, 2
None
None
Yes, 1 dog
Yes, 1 vaccinated dog
None
None
Yes, 3 unvaccinated
cats
Yes, 1 dog sniffing bat
None
Yes, 1 person with
physical contact
None
None
None
None
Massac (Belknap)
Found in backyard; died
Bat found in bedroom;
flew at boy and physical
contact
Outside; hit with broom,
boiling water then bleach
Outside
None
Mchenry
(Woodstock)
Bat in home; while
remodeling
Yes, 1 bitten while
painting house
None
218649
218650
6/6
6/6
Whiteside (Morrison)
McHenry
(Woodstock)
Cook (Winnetka)
218648
6/6
218652
6/14
218653
6/14
218651
218654
3230
218664
218665
6/14
6/17
6/19
6/26
6/27
218667
6/29
218666
6/29
218668
218673
7/2
7/3
McHenry
(Woodstock)
Lake (Ingleside)
Kane (Elgin)
218669
7/4
Lake (Zion)
218671
7/9
218670
7/9
McHenry (Crystal
Lake)
McHenry
(Woodstock)
Tazewell (Morton)
Peoria (Peoria)
Cook (Elgin)
Lake (Antioch)
McHenry
(Woodstock)
Lake (Antioch)
143
Yes, 1
Yes, 1 dog caught bat
218672
218674
7/12
7/16
Madison (Collinsville)
Clinton (Trenton)
Backyard
Backyard
218675
218676
7/17
7/18
Cook (Orland Park)
Whiteside (Morrison)
Alive in bathtub
Found on porch
218678
218677
7/24
7/24
Lake (Waukegan)
Dupage (Oakbrook)
On driveway
Found outside
218679
218680
7/30
7/31
DuPage (Naperville)
McHenry (Marengo)
In home
In home
218683
8/1
Will (Beecher)
218682
218681
8/2
8/2
Cook (Chicago)
Mercer (Aledo)
218684
8/3
Lee (Amboy)
Bat flying in house near
sleeping area
In building
In room where sleeping
people
In home
218686
218685
8/6
8/6
Will (New Lenox)
Williamson (Stiritz)
Found outside
Found outside
None
None
218687
8/6
Bat found in bedroom
3 children
218696
218691
8/7
8/8
Winnebago
(Rockford)
Cook (Chicago)
Winnebago
Unknown
Found in home
2 persons given PEP
None
144
None
Bat flew out of leaf
bag and physical
contact
None
None
None
Yes, 1 landscaper
bitten when he picked
it up
None
Yes, 1 had mark on
wrist; not sleeping in
room where bat was
4 received PEP
Yes, 1
3 sleeping persons in
room with bat
None
None
None
None
Yes, 1 vaccinated dog
had bat in mouth
None
None
None
Unknown
None
2 cats; both euthanized
and tested negative for
rabies
None
Yes, vaccinated dog
picked up bat
None
None
(Rockford)
McHenry (Crystal
Lake)
McHenry
(Woodstock)
Kane (Aurora)
Cook (Glencoe)
Will (Naperville)
Cook (Chicago)
Cook (Chicago)
Warren (Monmouth)
Cook (Orland Park)
Will (Bolingbrook)
Will (Joliet)
Sangamon
(Springfield)
218690
8/8
On deck
None
None
218688
8/8
Bat in basement where
sleeping
1 person
None
218703
218694
218689
218697
218698
218692
218693
218707
218708
218700
8/9
8/9
8/10
8/11
8/12
8/12
8/12
8/13
8/13
8/15
1, bite to hand
None
None
1
Yes, 4
None
None
None
None
1, picked up bat with
bare hands; received
PEP; only 2 doses
needed
6 persons sleeping in
room
Unknown
3
None
None
None
None
None
None
2 cats in home
None
None
None
None
218699
8/13
Cook (Chicago)
Found in room
218704
218701
218702
8/17
8/17
8/17
Cook (Glencoe)
Cook (Chicago)
Cook (Chicago)
218705
218706
218709
8/17
8/17
8/21
218710
8/20
Cook (Winnetka)
Cook (Des Plaines)
Madison
(Edwardsville)
Winnebago
(Rockford)
In house
In bedroom with mother
Found in apartment
complex hall
Found in home
Found in home
In bathroom
Unknown
Unknown
Yes, 1 physical
contact with bat
Yes, 2; one sleeping
in room; one physical
Possible cat exposure
None
None
In home
Outside house
Bat found in bathroom
In house
Dead bat in home
Dead in pool
Found in pool
Found in school hall
Outside office building
In bedroom of mother
145
None
Unknown
Unknown
Unknown
None
218711
8/20
8/21
Grundy (Morris)
Lee (Dixon)
Found in church
Bat in home
218713
8/21
Kane (Aurora)
218715
8/23
Kane (Aurora)
Bat flying around
bedroom
Bat flying in bedroom
218716
218714
8/23
8/23
8/23
Cook (Chicago)
McHenry (Harvard)
Cook (Midlothian)
Unknown
In yard; owner killed bat
Bat found in basement
218716
8/25
Cook (Chicago)
218717
218710
8/26
8/28
Cook (Chicago)
Winnebago
(Caledonia)
Bat in living room
Unknown
218729
281723
218724
218726
218725
218729
218728
8/28
8/30
8/30
8/30
8/30
8/30
8/31
218727
9/1
Will (New Lenox)
Lake (Libertyville)
Cook (Mt Prospect)
Cook (Mt Prospect)
Cook (Schaumburg)
Will (New Lenox)
McHenry
(Woodstock)
Cook (Chicago)
Found in office
Unknown
Bat in home
Bat in home
Bat in home
Bat in park
Bat flew in house thru
window
In apartment
146
contact
None
3 persons receiving
PEP; no known
exposure
Yes, 1
None
Dogs in crates
Yes, 4 received PEP;
all in bedroom
sleeping
None
None
No, 1 received PEP,
no one in room
sleeping
None; put box over
bat
Yes, 2
None
Dog smelled bat
None
Unknown
Unknown
Unknown
Unknown
None
None
None
Unknown
Unknown
Unknown
Unknown
None
None
None
None
None
None
Unknown
None
None
None
218730
9/4
Champaign (Tolono)
Found outside
None
218731
218733
9/4
9/4
Lee (Franklin Grove)
Kane (Aurora)
Bat in bedroom
In bedroom
218745
9/4
Unknown
218734
218735
9/5
9/5
Bat in home
Living room
None
None
218740
218732
9/6
9/6
McHenry
(Woodstock)
Madison (Alton)
Sangamon
(Springfield)
Effingham (Watson)
LaSalle (Mendota)
1 person bitten
2, in room with bat
when sleeping;
received PEP
None
Bat found on chicken
Bat killed with pillow
None
1 person received
PEP, only touched the
pillow
Chicken
Unknown
218739
218742
9/11
9/11
Hot tub
Outside residence
None
None
None
None
218741
9/12
Will (Homer Glen)
Winnebago
(Rockford)
Madison (Highland)
Unknown
None
218744
218743
218749
9/13
9/17
9/22
Will (Joliet)
Lake (Highland Park)
Mclean (Normal)
None
None
None
218751
9/22
218746
218747
218748
9/24
9/25
9/25
Wiliamson
(Thompsonville)
Lake (Antioch)
Will (Godley)
Sangamon
Swimming pool
Outside
Found outside on screen
door
Brought to person by
dog
Kitchen
Found in yard
Bat in house
Unvaccinated cat caught
and killed bat
Unknown
None
None
147
None
None
None
None
Unvaccinated barn cat
with bat in mouth
None
None
Dog had bat found in
mouth
None
None
2 vaccinated dogs; one
had bat in mouth
None
None
None
218750
218752
9/25
9/26
218753
218755
10/1
10/9
218756
10/20
218757
10/26
218758
218759
10/30
10/30
218760
11/13
(Springfield)
McHenry (Algonquin)
Madison
(Edwardsville)
Will (Homer Glen)
Cook (Arlington
Heights)
Mclean
(Bloomington)
Cook (Chicago)
Cook (Palos Heights)
Jackson
(Carbondale)
Lee (Amboy)
Unknown
Unknown
None
None
None
Unknown
Found outside building
House
None
None
None
Unvaccinated dog
Found in basement
None
None
Found outside
None
Found in forest preserve
Outside
None
None
Vaccinated dog sniffed
or picked up bat; did not
receive booster
None
None
Found in basement
None
None
148
Figure 73. Animal rabies cases in Illinois by County, 2007
149
Table 8. Bat Speciation Results from Bats Submitted for Rabies Testing in 2007
Species
Common Name # testing neg. # testing pos.
Eptesicus
Big brown bat
1436
87
fuscus
Lasiurus
Eastern Red bat
154
14
borealis
Lasiurus
Hoary bat
20
3
cinereus
Lasionycteris
Silver-haired bat
270
3
noctivagans
Pipistrellus
Eastern
9
1
subflavus
pipistrelle
Myotis
Little brown bat
45
1
lucifugus
Myotis
Northern long39
1
septentrionalis eared bat
Nycticeius
Evening bat
10
0
humeralis
Myotis sodalis Indiana bat
0
0
Myotis
Gray bat
0
0
grisescens
Corynorhinus
Rafinesque’s
0
0
rafinesquii
big-eared bat
Myotis
Southeastern
0
0
austroriparius
bat
Unknown
5
0
TOTAL
1988
110
Source: Illinois Natural History Survey
# unsatisfactory
29
7
0
2
1
3
1
0
0
0
0
0
4
47
Figure 74. Bats Tested by Month in Illinois, 2007
800
700
600
500
400
300
200
100
0
50
40
30
20
10
0
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
150
Number of bats tested
Positive bats
Table 9. Rabies Positivity Rate by Animal Species in Illinois, Selected Time
Spans.
1971-2007
Species
1991-2007
# tested
# positive
% positive
# tested
# positive
% positive
Bat
16,997
805
4.74
11,824
503
4.25
Cat
46,574
141
0.30
19,576
4
0.02
Cattle
3,975
215
5.41
1,543
4
0.26
Dog
49,464
110
0.22
25,919
5
0.02
Fox
1,454
73
5.02
269
1
0.37
Horse
790
23
2.91
333
1
0.30
Mouse
4,770
0
0.00
725
0
0.00
Raccoon
10,027
17
0.17
3,745
0
0.00
Rat
1,896
0
0.00
386
0
0.00
Skunk
7,963
2,532
31.80
1,795
50
2.79
Squirrel
7,192
0
0.00
2,030
0
0.00
Source: Illinois Department of Public Health
05
20
9
02
20
19
9
19
96
19
93
90
19
87
19
84
19
19
19
7
81
Year
Rabid skunk
Road kill index
151
Road kill
index
6
4
2
0
8
600
400
200
0
19
75
Number of
rabid
skunks
Figure 75 . Skunk Rabies and Skunk Road Kill Index
in Illinois, 1975-2007
Rabies, potential human exposure
Background
Exposures to animals, especially those involving bites or bat exposures, often result
in the need for public health consultation on whether rabies post-exposure prophylaxis
(PEP) is needed for the exposed individual. All animal bites in Illinois are reportable to
local animal control for the purposes of following up with the owner of the biting animal.
Animal control authorities are responsible for ensuring that dangerous animals are
maintained so that they cannot injure the public. Potential human rabies exposures are
reportable to human health including all instances when rabies post-exposure prophylaxis
is initiated and all exposures to bats.
Case definition
The definition of exposed person to be reported is:
1)
Any contact (bite or non-bite) with a bat, or
2)
Any contact (bite or non-bite) with an animal that subsequently tests
positive for rabies virus infection, or
3)
Anyone who was started on rabies post-exposure prophylaxis, or
4)
Exposure to saliva from a bite, or contact of any abrasion or mucus
membrane with brain tissue or cerebrospinal fluid of any suspect rabid
animal. Exposure to healthy rabbits, small rodents, indoor-only pets or
rabies-vaccinated dogs, cats or ferrets is excluded, unless the exposure
complies with subsections (a)(1) through (a)(3) above, or the animal
displays signs consistent with rabies.
Descriptive epidemiology
The following information was obtained from Illinois National Electronic Disease
Surveillance System and investigation forms obtained during the surveillance of rabies,
potential human exposures (RPHE) in Illinois during 2007. The investigation forms had
questions on demographics, exposure characteristics and rabies post-exposure
treatment information. Not all local health jurisdictions have submitted investigation
forms so this is a minimum estimate of the number of potential human rabies exposures
in Illinois.
•
•
•
Number of cases reported in Illinois in 2007 - There were 440 potential human
rabies exposures reported.
Age – Ages ranged from less than one year of age to 93 years of age. The mean
age of those exposed was 32 years.
Gender – Forty-nine percent of RPHE reports were in males.
152
•
•
Seasonal peak – Higher numbers of exposures occurred in the summer months
of May through August (Figure 76).
Geographic location – Forty-seven counties reported at least one RPHE. Sixtysix percent of exposures took place in urban settings. Counties reporting the
most cases included McHenry (58), DuPage (53), Cook (35) and Kane (31).
Type of exposure
Three types of exposures can be summarized from the reports: bite, non-bite
(scratch or abrasion or contamination of open cuts with saliva or nervous tissue, bat
present in room with sleeping person or physical contact with a bat where a bite cannot
be ruled out) or non-exposure (petting, handling, blood contact, bat in room but no
physical contact and no one asleep). Of the 433 exposures with information reported
about type of exposure, 127 (29 percent) were due to animal bites, 238 (55 percent)
from non-bite exposures and 68 (16 percent) no human exposure meeting ACIP
guidelines for rabies PEP.
Of the 100 bite exposures with the site of bite reported, most bites were to the
arm or hand, 71 (71 percent), followed by leg or foot, 17 (17 percent), head or neck, 10
(10 percent) and torso, two (2 percent). The bite site was not indicated for 27 bite
exposures.
Of the 233 non-bite exposures due to bats, bats were found in the room with a
sleeping person in 198 (85 percent) of exposures, physical contact with a bat took place
in 26 (11 percent) of exposures, a young child or an adult with dementia was
unobserved with a bat in two (0.8 percent) and bat was in a house but not in sleeping
area (2 percent). Other non-bite exposures included bat hissing at person and someone
with marks on the body after sleeping. Bats were tested in 63 (27 percent) of the nonbite bat situations. Thirty-three bats tested negative, 26 tested positive and four
specimens were unsuitable for testing. The other non-bite exposures included exposure
to saliva from raccoons (three).
Animals causing exposure
The following information is by each individual person’s exposure history.
Multiple individuals may have been exposed to a single animal. Of 429 known type of
animals causing exposures, 380 (88 percent) were wild, not domesticated animals. The
types of animals causing exposures included bat, 349 (81 percent); cat, 22 (5 percent);
dog, 25 (6 percent); raccoon, 21 (5 percent) and other, 11 (2.5 percent). The type of
animal was unknown for two exposure situations. Of the 49 domestic animals exposing
persons, 25 (67 percent) were described as stray and 26 (32 percent) were owned. For
12 animals, the ownership was not described. Of the 25 dogs that exposed an
individual, 20 (80 percent) of these animals had an unknown vaccination history, four
(16 percent) were up-to-date on rabies vaccination and one (4 percent) was previously
vaccinated but not up-to-date on rabies vaccinations. Rabies vaccination of dogs is
required in Illinois. Of the 22 cats that exposed an individual, 18 (82 percent) of these
animals had an unknown vaccination history and four (18 percent) were not rabies
vaccinated. Twenty-six of 37 (70 percent) of bites from dogs and cats were provoked
where the type of exposure was described.
153
For 49 domestic animal exposures, 35 of 42 (83 percent) were unavailable for
either confinement or testing, two (5 percent) were tested for rabies and five (12
percent) were confined for observation. The outcome for seven domestic animals was
not known. One (8 percent) of the 12 owned domestic animals were owned by the
family of the person bitten and 11 (92 percent) were owned by another individual.
There were 262 (70 percent) of 376 wild animals that were not available for
confinement or testing. One hundred fourteen (30 percent) of animals potentially
exposing someone to rabies were submitted for rabies testing. Four wild animals had an
unknown disposition. Of the 114 wild animals submitted for rabies testing, 64 (56
percent) were negative, 44 (39 percent) were rabies positive and six (5 percent) were
unsuitable for testing. Forty-four people were exposed to known rabid bats. The
specimens that were unsuitable for testing were from five bats and one coyote.
In 20 exposures, the exposing animal was reported to exhibit signs of rabies.
Signs of rabies included aggression, three (15 percent); no fear of humans, six (30
percent); impaired locomotion, five (25 percent); other, four (20 percent) and multiple,
two (10 percent).
Rabies post-exposure prophylaxis (PEP)
During 2007, 377 persons were reported to have started rabies PEP. The first
recommendation about whether rabies PEP was needed for a person starting rabies
PEP came from the following sources: public health personnel, 188 (51 percent), health
care provider, 179 (49 percent) and other, one (0.3 percent). For nine cases the source
of the recommendation was not known.
The final recommendation on rabies PEP for those starting rabies PEP came
from public health personnel, 192 (52 percent); health care provider, 175 (48 percent)
and other, one (0.3 percent). For nine exposed persons receiving PEP, the source of
the final recommendation was not known.
For 229 (76 percent) of 303 persons with information available, rabies PEP was
completed in an emergency department followed by completion in a physician’s office,
54 (18 percent) and completion at a local health department, 20 (7 percent). Most rabies
PEP was paid for by private insurance, 144 (77 percent), followed by Medicare or
Medicaid, 24 (13 percent), no payment source, 10 (5 percent), worker’s compensation,
three (2 percent) and out-of-pocket expense, seven (4 percent). Payment source was
unknown for 189 persons. Sixteen of 381 (4 percent) of persons recommended for
rabies PEP refused to be treated. None developed rabies.
Rabies PEP was completed in 305 (82 percent) of 374 persons for whom
information was available. In 44 persons (12 percent), rabies PEP was not completed.
In 25 persons rabies PEP was not completed because the animal was tested negative.
Of these 25 situations, 22 were bat exposures, two were raccoon exposures, and one
was a cat exposure. The rabies PEP recommendation for 40 of these persons was
made mainly by health care providers (24 situations), followed by public health
departments (16). In three (7 percent) of situations, the animal was a low-risk species,
in eight (19 percent) of situations the patient refused to complete treatment, in four
situations the person was lost to follow-up, in two situations the animal survived the
confinement period, in one situation the person had a reaction to the vaccine and the
154
reason was unknown for one person.
Decisions on rabies PEP should be based on the Advisory Committee on
Immunization Practices (ACIP) guidelines. For 420 exposed persons, it was possible to
determine if the PEP recommendation followed ACIP guidelines. For 287 (68 percent)
of these persons, rabies PEP was recommended and the recommendation followed
ACIP guidelines. For 94 (22 percent) of persons, rabies PEP was recommended but this
was not correct according to ACIP guidelines. For 39 persons (9 percent), rabies PEP
was not recommended and that was correct according to ACIP. There were no persons
for whom PEP was not recommended and that was an incorrect recommendation. In 94
situations, PEP was recommended incorrectly. In 48 situations, PEP was recommended
when a bat was found in a building, even though no one was sleeping in the room and
no one was exposed who was unable to accurately report an exposure. The ACIP
recommends rabies PEP if the bat is found in a room with a sleeping person or person
who is unable to say whether they were bitten. In 23 situations an animal that exposed
someone tested negative for rabies but PEP was started. Because the turnaround time
is rapid for rabies testing, PEP can be delayed until the testing of the animal takes
place. Because of the lack of terrestrial animal rabies in the last few years in Illinois, no
rabies PEP would be recommended if the dog or cat bite was provoked and the animal
showed no signs of rabies. In 18 situations, persons were recommended for PEP even
though a domestic animal exposed the person with a provoked bite and was not acting
abnormally. In three situations a low risk animal, rodent or opossum, bit someone and
PEP was recommended. In two situations persons who were not exposed to saliva or
neurologic tissue were incorrectly recommended for rabies PEP.
Of the 377 persons who started rabies PEP, 305 of 349 (87 percent) completed
rabies PEP. For 70 of 188 (37 percent) persons completing rabies PEP and with
information available, the ACIP rabies protocol was followed exactly. There were 118
people who had incorrect administration of rabies PEP. Types of incorrect
administration were incorrect timing of injections (89, 75 percent), multiple problems
(17, 14 percent), no RIG given (two, 2 percent), incorrect site of administration of
injections (seven, 6 percent) and other (three, 2 percent).
Eight persons started on rabies PEP had been pre-exposure immunized for
rabies.
There were seven persons exposed outside the United States and 13 exposed
outside Illinois but within the United States.
Summary
There is vast underreporting of potential human rabies exposures in Illinois with
some jurisdictions not reporting any exposures. Therefore, the summary information is
not a complete picture of human rabies exposures in Illinois. Twenty-nine percent of
reported exposures were due to bites. Most bites were to the hand or arm which is
typical as persons reach to pick up or handle an unfamiliar animal. Of the non-bite
exposures, 85 percent of reported exposures were from bats found in a room with a
sleeping person. Education of the public and animal control personnel could result in
increased submission of bats that have exposed person in homes being tested for
rabies. If the bat tests negative, the person would not need rabies PEP.
155
The main animal causing potential human rabies exposures was the bat,
followed by the cat, dog and raccoon. This is primarily due to the definition of possible
rabies exposure to a bat. The bat is the only wild mammal where rabies PEP is
recommended if a person is in a room sleeping where a bat is found and it cannot be
tested, or tests positive.
Forty-eight percent of final rabies PEP recommendations were made by
emergency department health care providers or other health care providers. This
indicates the importance of providing health care providers with up-to-date information
on rabies incidence in their area and on rabies PEP recommendations.
Twenty-two percent of the rabies PEP given in 2007 would not have been
indicated according to public health guidelines. In some situations persons were started
on rabies PEP even though the animal was available for testing. Health care providers,
especially in emergency departments, should be advised that rabies testing of animals
can be completed rapidly at the state laboratories, and, if necessary, emergency testing
can be requested for high priority specimens on holidays or weekends. For emergency
testing, health care providers can contact local health department personnel or use the
state emergency phone number if it is after hours. Rabies PEP can be delayed until
testing is completed if testing is prompt.
The rabies PEP protocol is provided in, “Human Rabies Prevention-United
States, 1999. Recommendations of the Advisory Committee on Immunization Practices
(ACIP): MMWR 1999;48(RR-1)”. In 37 percent of cases where rabies PEP was
completed, PEP was administered correctly. Common errors in administration included
incorrect timing of injections and forgetting to administer RIG. The ACIP
recommendation for rabies PEP should be adhered to when administering rabies PEP.
It can be difficult to get exposed individuals to adhere to a complicated vaccination
schedule but the person should be informed about the universally fatal nature of rabies
and the importance of adhering to the ACIP schedule.
Number of cases
Figure 76. Rabies, Potential Human Exposure Cases in Illinois by
Month, 2007
200
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
156
Aug
Sep
Oct
Nov
Dec
Rocky Mountain spotted fever
Background
Rocky Mountain spotted fever (RMSF) is the most frequently reported fatal tickborne disease in the United States. RMSF has been reported throughout the
continental United States. The causative agent is Rickettsia rickettsii. Both dogs and
humans may experience clinical illness due to RMSF.
In 2007, 2,221 human cases were reported nationally to the CDC. Most cases
are reported from April through September when the greatest number of Dermacentor
ticks are present in the environment.
The ticks that are most likely to transmit RMSF include the American dog tick
(Dermacentor variabilis) in the central United States. Only about 1 percent to 5 percent
of ticks are usually infected with R. rickettsii in an area where transmission to humans
occurs. In order for one of these ticks to transmit the bacteria, it must be attached for at
least four to six hours. A history of a tick bite can be elicited in approximately 60 percent
of RMSF cases.
The incubation period for RMSF is three to 14 days after a tick bite. Common
presenting symptoms include high fever, severe headache, deep myalgias, fatigue,
chills and rashes. A rash typically appears within two to four days after onset of fever.
The rash typically begins on the ankles, wrists or forearms. A rash can be atypical or
absent in up to 20 percent of RMSF cases. Starting most often on the ankles and wrists,
the rash then appears on the trunk, palms and soles. Patients also may have
gastrointestinal signs such as abdominal pain and nausea which may be serious
enough to lead to an erroneous diagnosis such as appendicitis. RMSF can have a case
fatality rate of 20 percent in untreated persons, while the case fatality rate is 5 percent in
treated persons.
Case definition
The case definition for a confirmed case of RMSF in Illinois is a clinically
compatible illness that is laboratory-confirmed. The laboratory confirmation is a four-fold
or greater rise in antibody titer by immunofluorescent antibody (IFA), complement
fixation (CF), latex agglutination (LA), microagglutination (MA) or indirect
hemagglutination antibody (IHA) test in acute and convalescent specimens ideally taken
more than three weeks apart; or demonstration of positive immunofluorescence of a
skin lesion or organ tissue, positive polymerase chain reaction or isolation of R. rickettsii
from a clinical specimen. A clinically compatible illness is one characterized by acute
onset and fever, usually followed by myalgia, headache and petechial rash. A probable
case is defined as a clinically compatible case with a single IFA serologic titer of at least
64 or a single CF titer of at least 16 or other supportive serology (four-fold rise in titer or
a single titer at least 320 by Proteus OX-19 or OX-2, or a single titer at least 128 by an
LA, IHA or MA test).
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – There were 39 cases; all were
probable cases. (five-year median = 12)
157
•
•
•
•
•
•
•
•
•
Age - Cases ranged in age from two to 78 years of age (mean = 38 years).
Gender – Twenty-one cases were male (54 percent).
Race/ethnicity – Thirty-five cases were white, two reported other race; and three
cases had unknown race; No cases were Hispanic.
Geographic distribution – Fifty-four percent of the cases resided in the southern
Illinois region.
Seasonal variation - Onsets of the cases ranged from February to November
(Figure 77). An increase in cases occurred from April to October (35 cases).
Symptoms/outcomes – Symptoms reported by cases included fever in 28 cases (78
percent), rash in 24 cases (73 percent), headache in 24 cases (65 percent)
thrombocytopenia in four cases (15 percent) and neurologic in one case (3
percent). Sixteen of 38 cases (42 percent) were hospitalized. No cases were fatal.
Tick exposure – Twenty-five of 32 (78 percent) of cases with a tick habitat history
reported being in a tick habitat. Of the persons who reported the type of tick
habitat, the following location types were reported: own property (11), farm (five),
park or nature preserve (three) and campground (two). Ten cases did not report the
type of location. Eighteen of 35 cases (51 percent) reported a history of a tick bite.
Twenty-nine cases reported exposures within Illinois. Tick exposures took place
primarily in the Marion region of southern Illinois (65 percent) followed by the
Edwardsville region (24 percent). One case each reported exposure in the following
regions, Rockford, Champaign and Peoria. Five cases reported out of state
exposures, Kentucky (two) and one each in Arkansas, Kentucky, Missouri and
multiple states. Five cases had unknown exposure histories.
Reporting – The majority of cases were reported by laboratories (67 percent).
Past incidence - Rocky Mountain spotted fever cases reported per year in the state
were: 1991 (five), 1992 (two), 1993 (four), 1994 (11), 1995 (10), 1996 (four), 1997
(three), 1998 (one), 1999 (seven), 2000 (five), 2001 (12), 2002 (12), 2003 (five),
2004 (14), 2005 (11) and 2006 (26).
Summary
Most cases of RMSF occurred in summer months primarily in southern Illinois.
The number of cases was more than three times higher than the five-year median.
Number of cases
Figure 77. Rocky Mountain spotted fever Cases in Illinois by Month,
2007
8
6
4
2
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
158
Aug
Sep
Oct
Nov
Dec
Rubella
Background
Rubella or German measles usually causes a mild febrile illness. Adults may
experience fever, coryza and conjunctivitis. The incubation period ranges from 14 to 21
days. Rubella can also cause anomalies in a developing fetus.
Twelve cases were reported to CDC from eight states or territories in 2007.
Case definition
A confirmed is a case that is laboratory confirmed (isolation of rubella virus or
significant rise in titer between acute and convalescent titers or a positive IgM serologic
test or that is clinically compatible with all the following characteristics:
•
•
•
Acute onset of generalized maculopapular rash
Temperature greater than 99.0 F (greater than 37.2 C), if measured
Arthralgia/arthritis, lymphadenopathy, or conjunctivitis
and is epidemiologically linked to a confirmed case.
A probable case is one that meets the clinical case definition, had no or noncontributory
serologic or virologic testing, and is not epidemiologically linked to a laboratoryconfirmed case.
Descriptive Epidemiology
Number of cases in Illinois in 2007 – One case was reported.
Individual case description
• The case was a 34-year-old visiting Chicago from Russia. He had onset of rash
illness in March. He also had cough, coryza and conjunctivitis.The infection was
acquired overseas. He was a confirmed case and serologically positive.
Summary
A single imported case of rubella was reported in a traveler to Illinois.
159
Salmonellosis (Non-typhoidal)
Background
There are more than 2,400 serovars of Salmonella. However, approximately 50
percent of human cases are caused by three serovars: Salmonella enterica ser
Enteritidis, S. ser Typhimurium and S. ser Newport. Transmission to humans is usually
after consumption of contaminated food products. Raw or undercooked meat, eggs, raw
milk, and poultry have been identified as vehicles for Salmonella infection. Fresh
produce, such as lettuce, unpasteurized apple or orange juice or sprouts also have
caused outbreaks. Hospital and commercial laboratories are required to submit isolates
of Salmonella to the Department’s laboratory for serotyping. This is necessary to detect
increases in specific serotypes. Identification of serotypes is useful in determining which
patients are likely linked to a common source of infection. Another way to link
Salmonella isolates to a common source is pulse field gel electrophoresis (PFGE). A
new laboratory technique for subtyping isolates is multiple-locus variable-number
tandem repeats analysis (MLVA), may prove to be useful in surveillance and outbreak
investigation. This technique is currently available at CDC.
In the United States national surveillance data, 47,995 cases were reported to
CDC in 2007. The majority of cases occurred in persons younger than five years of age.
Seven serotypes comprised 62 percent of infections: Enteritidis (17 percent),
Typhimurium (16 percent), Newport (10 percent), I 4,5,12:i:- (6 percent), Javiana (5
percent), Heidelberg (4 percent) and Montevideo (3 percent). The 2010 National Health
objective is 6.8 per 100,000. Overall the incidence did not change from the 2004 to
2006 incidence. The incidence of Typhimurium and Heidelberg decreased and I
4,5,12:i- and Newport increased.
Of the 10 diseases/syndromes (those caused by Campylobacter,
Cryptosporidium, Cyclospora, shiga toxin producing E. coli O157:H7, HUS, Listeria
monocytogenes, Salmonella, Shigella, Vibrio and Yersinia enterocolitica) under active
surveillance in the federal FoodNet sites, Salmonella comprised 41 percent of the
reported infections in 2007. The incidence rate was 14.9 per 100,000 and ranged from
8.5 to 21.4 at the 10 FoodNet sites in 2007. In data from 2007, 94 percent of isolates
were serotyped. The top seven serotypes were: Enteritidis (16 percent), Typhimurium
(15 percent), Newport (10 percent) and I 4,[5],12:i:- (5 percent).
Multi-state otbreaks from contaminated peanut butter, frozen pot pies and a
puffed vegetable snack occurred in 2007. In the United States national surveillance
data, 47, 995 cases of Salmonella were reported to CDC in 2007. Serotypes
Typhimurium and Enteritidis are the most common. Multi-state outbreaks of Salmonella
occurred in 2007. Sixty-nine patients from 23 states with S. ser. Wandsworth had illness
strongly associated with consumption of a ready-to-eat puffed snack food. The
organism was isolated from product and ill patients and matched by PFGE. An outbreak
of S. ser. Schwarzengrund occurred in persons and was linked to exposure to
contaminated dry dog food. A case-control study linked illness to buying the dry dog
food. The organism was found in dog stool from one household where human cases
resided and with the suspect dog food. The outbreak strain was identified in
environmental samples from the plant producing the dog food and from previously
160
unopened dry dog food. The product was recalled. A multi-state outbreak of S. ser.
Paratyphi B var. Java occurred following exposure to small turtles in 2007 and 2008.
Water samples from turtle habitat were also positive for the same strain. Eighty-six
percent of turtles in households involved in a case-control study were less than four
inches. One third of the turtles were purchased at pet stores and one-quarter were
received as gifts. An outbreak of Salmonella was linked to consumption of raw milk and
cheese in Pennsylvania. The bulk milk tank was also positive for the same strain of
Salmonella.
In a study in Washington state, risk factors associated with sporadic Salmonella
infection included exposure to aquatic recreation, using private wells and residential
septic systems and raw sprout consumption.
Case definition
The case definition for a confirmed case is isolation of Salmonella from a clinical
specimen. The case definition for a probable case is a person who has a clinically
compatible illness that is epidemiologically linked to a confirmed case, but is not
laboratory-confirmed. A case that is cultured at a commercial or hospital laboratory is
counted as a probable case if the isolate is not forwarded to the state laboratory for
confirmation.
Descriptive epidemiology
•
•
•
•
•
•
•
•
Number of cases reported in Ilinois in 2007- There were 1,966 cases reported (fiveyear median = 1,770) (see Figure 78). Fifty-three cases were probable, the rest were
confirmed. The annual incidence rate for salmonellosis in Illinois in 2007 was 16 per
100,000 population.
Age – Salmonellosis occurred in all age groups (mean age = 33) (see Figure 79).
However, the incidence rate was highest in those younger than 1 year of age (70
cases per 100,000 population), followed by those in the 1 to 4 year age group (33
per 100,000).
Gender – Fifty-four percent were female.
Race/ethnicity – Eighty-two percent of cases were white, 13 percent African
American and 15 percent other races; Twenty percent were Hispanic.
Seasonal variation - A peak in salmonellosis cases occurred in the summer months,
especially July (Figure 80).
Geographic distribution – For 2007, the counties with the highest incidence per
100,000 population were Jasper (49), Kendall (46), Hardin (42), Kankakee (37),
Scott (36) and Kane (33).
Serotypes - Ninety-six percent of Illinois’ Salmonella isolates were serotyped. The
most common serotypes in 2007 are found in Table 10. The three most common
serotypes were S. ser.Typhimurium (377, 20 per cent), S. ser. Enteritidis (331, 17
percent) and S. ser. Heidelberg (224, 12 percent). Serotypes of Salmonella found in
Illinois from 1999-2007 are shown in Table 11.
Clinical syndrome – Cases reported diarrhea (93 percent), fever (68 percent) and
vomiting (39 percent). Thirty-three percent were admitted to the hospital. Two deaths
161
•
•
were attributed to Salmonella and an additional eight persons died with Salmonella.
Site of isolation – The sites of isolation for cases include stool or rectal swab (1,279
cases), urine (70), blood (67), wound or abscess (six), other (11), multiple sites (24)
and unknown (456). The other sites included peritoneal fluid (two), synovial (two),
bronchial wash (one), gall bladder (one), vagina or uterus (three), tissue, unspecified
(one) and skull plate (one). There are many unknown sites because many
Salmonella laboratory results with electronic transmission have isolate as the site
where the isolate was obtained.
Risk factors –
Animal contact
• Contact with animals was reported from 630 of 1,448 (43 percent) of cases. A
history of reptile or amphibian contact was reported by 85 Salmonella cases
in 2007, but a link between the reptiles and transmission of the infection was
not confirmed by culture of reptiles or amphibians.
• Cases reported contact with the following types of reptiles or amphibians:
turtles (25), lizards (17), snakes (11), frog/toad (two), alligator (one), not
specified (16) and multiple types (12). Two of the turtles were known to be
less than four inches.
• For those with reported reptile or amphibian contact, the mean age was 18
years; 24 cases were younger than five years of age.
• Males accounted for 52 percent of the cases.
• The two most common species in these cases were Enteritidis (15) and
Typhimurium (12).
Travel exposure
o Of the 1,494 cases with information available, 160 cases (11 percent)
reported travel to another country. The most common destination was Mexico
(78 cases), followed by India (14) and Dominican Republic (seven). Traveling
to another state was reported by 125 (8 percent) of the cases. Wisconsin (22
cases), Florida (13) and Michigan (10) were the most common states visited.
Most S. ser. Paratyphi A cases were acquired overseas (Table 12). Almost a
quarter of S. ser. Enteritidis cases were acquired outside the United States.
Swimming exposure
o Eighty-nine of 1,533 cases (6 percent) reported swimming in non-chlorinated
water and 161 of 1505 cases (11 percent) reported swimming in chlorinated
water. Seventy-five cases reported drinking well water.
Residential or day care exposure
o One-hundred and sixty-nine of 1,562 cases (11 percent) reported contact with
a residential facility and 108 of cases (7 percent) reported contact with a day
care.
o Thirty-one cases attended a day care and six cases lived in a residential
facility.
162
•
•
Sensitive occupations
o Sensitive occupations reported by cases included health care worker (37),
food service facility worker (33), residential facility (three), day care center
(two) and other sensitive occupations (34).
Reporters – Cases were reported primarily by laboratory staff (48 percent) followed
by infection control professionals (45 percent) and health clinic staff (3 percent).
Outbreaks - There were 12 confirmed foodborne outbreaks of Salmonella reported in
2007. (See the section of this report detailing foodborne outbreaks for more
details.). There were two multi-state outbreaks due to animal contact and one
Salmonella outbreak with an unknown mode of transmission (See the section of this
report detailing non foodborne non waterborne outbreaks). No person-to-person
outbreaks were reported due to Salmonella.
Summary
In 2007, 1,966 cases of Salmonella were reported in Illinois. The one-year
incidence rate of Salmonella for 2007 was 16 per 100,000 population, which is higher
than the average incidence reported at CDC’s FoodNet sites (15 per 100,000). The
mean age for Salmonella cases was 33 years, although the incidence was highest in
those younger than one year of age. Salmonella cases increased in Illinois during the
summer. The percentage of isolates that were serotyped in Illinois was 96 percent as
compared to 94 percent in the FoodNet sites. The percentages of the three most
common serotypes were Typhimurium (20 percent) and Enteritidis (17 percent), and
Heidelberg (12 percent). A higher proportion of Illinois isolates serotyped in Illinois were
S. ser. Heidelberg (12 percent) as compared to 2007 FoodNet data (4 percent). This
was due to a large S. ser. Heidelberg outbreak that occurred in Illinois, with 191
laboratory confirmed cases. The proportions of S. ser. Typhimurium (20 percent) was
higher and S. ser. Enteritidis was the same percent as reported by the 2007 FoodNet
data for those serotypes. Reptile or amphibian contact was reported in 24 cases
younger than 5 years of age. CDC recommends that households with children younger
than 5 years of age not have reptiles as pets.
Suggested readings
Austin, C. et al. Outbreak of multidrug-resistant Salmonella enterica serotype
Newport Infections associated with consumption of unpasteurized Mexican-style aged
cheese – Illinois, March 2006-April 2007. MMWR 2008; 57(16):432-35.
Bergmire-Sweat, D., et. al. Multistate outbreak of human Salmonella infections
associated with exposure to turtles-United States, 2007-1008.
Centers for Disease Control and Prevention. FoodNet 2007 Surveillance Report.
Atlanta, GA. U.S. Department of Health and Human Services, 2009.
Denno, D.M., et. al. Tri-county comprehensive assessment of risk factors for
sporadic reportable bacterial enteric infection in children. JID 2009;199:467-476.
Ferraro, A., et. al. Multistate outbreak of human Salmonella infections caused by
contaminated dry dog food-United States, 2006-2007. MMWR 2008;57(19):521-24.
Vugia, D., et. al. Preliminary FoodNet data on the incidence of infection with
pathogens transmitted commonly through food-10 states, 2007. MMWR 2008; 57(140:
163
366-69.
Salmonella Typhimurium infection associated with raw milk and cheese
consumption-Pennsylvania, 2007. MMWR 2007;56(44):1161-64.
Number of cases
Figure 78. Salmonella Cases in Illinois, 2002-2007
2500
2000
1500
1000
500
0
1955
1770
2002
2003
1966
1837
1612
2004
1603
2005
2006
2007
Year
Incidence per 100,000
Figure 79 . Salmonella Cases in Illinois by Age Group, 2007
80
60
Male
40
Fem ale
20
0
<1 yr
1-4 yr
5-9 yr
10-1 9 yr 2 0-29 yr 30-39 yr 40 -49 yr 50-59 yr
>59 yr
Age Group
Number of cases
Figure 80. Salmonella Cases in Illinois by Month, 2007
500
400
300
200
100
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
164
Aug
Sep
Oct
Nov
Dec
Table 10. Top 10 Salmonella Serotypes in Illinois, 2007.
Serotype
Frequency
Serotype
Frequency
Typhimurium
377
I 4,5,12:i-
46
Enteritidis
331
Infantis
45
Heidelberg
224
Montevideo
42
Newport
131
Oranienberg
39
Muenchen
95
Agona
34
Source: Illinois Department of Public Health
Table 11. Frequency of Salmonella Serotypes in Illinois, 1999-2007
Serotype
45:G-Z51:Aberdeen
Abony
Adelaide
Agbeny
Agona
Agoueve
Alachua
Albany
Altona
Amager
Amsterdam
Anatum
Antsalova
Apapa
Arizonae
Austin
Baildon
Bareilly
Barranquilla
Berta
Bledgam
Blockley
Bonariensi
Bovis-morb
Braenderup
Brandenburg
1999
0
0
0
3
0
48
0
1
2
0
0
0
7
0
0
1
0
0
6
0
9
0
4
1
5
28
5
2000
0
1
0
1
0
27
0
2
0
0
0
0
9
0
0
4
1
0
5
0
25
0
5
0
7
18
5
2001
0
0
0
4
0
14
0
0
1
0
0
0
10
0
0
2
0
0
7
0
41
0
1
1
3
16
9
2002
2003
0
0
0
0
0
20
0
1
0
0
0
0
9
0
0
3
0
1
5
0
19
0
3
1
2
21
2
0
0
0
6
0
16
0
1
0
0
0
0
15
0
0
1
0
2
1
0
23
0
2
0
7
32
12
165
2004
0
0
0
5
0
22
0
0
1
0
0
0
18
1
1
2
0
0
1
0
19
0
0
0
3
79
2
2005
0
1
0
9
0
33
0
0
2
0
0
2
13
0
0
2
0
1
6
0
17
0
2
0
2
36
14
2006
0
0
1
5
1
29
1
1
1
0
0
1
15
0
0
4
0
0
5
2
17
1
2
0
5
25
8
2007
2
2
0
15
6
34
0
0
0
1
1
0
18
0
0
1
0
0
2
0
13
0
1
1
8
19
7
Bredeney
Carmel
Carrau
Cerro
Chailey
Chameleon
Chester
Cholerae-suis
Serotype
Coeln
Colindale
Concord
Corvallis
Cotham
Cubana
Dahra
Derby
Dublin
Durban
Durham
Ealing
Eastbourne
Edinburg
Emek
Enteritidis
Finkenwerd
Flint
Fluntern
Freetown
Gaminara
Give
Goverdhan
Grumpensis
Guinea
Haardt
Hadar
Haifa
Hartford
Hato
Havana
Heidelberg
Herston
Hull
Hvittingfoss
I rough:b:1,2
I rough:d:l,w
I rough:e,h:
e,n,z,15
I rough:r:1,5
I 1,4,12,i:I 1,4,5,12:b:I 4,5: nonmotile
0
0
0
0
0
1
3
7
1999
0
0
0
1
2
1
3
4
2000
2
0
0
0
0
0
6
2
2001
1
0
0
0
0
1
1
1
2002
4
0
0
0
0
0
2
2
2003
2
2
0
2
1
0
0
2
2004
2
0
1
2
0
0
0
1
2005
1
0
1
0
0
0
1
1
2006
0
1
0
1
0
0
2
3
2007
0
0
0
0
0
0
0
14
0
0
0
1
1
0
1
264
1
2
0
0
1
4
0
0
0
0
15
0
16
0
2
101
0
0
1
0
0
0
0
0
0
0
0
1
0
14
0
0
0
0
1
0
0
262
0
0
0
0
0
1
0
0
0
0
26
1
18
0
2
101
0
1
3
0
0
0
0
2
0
0
0
2
0
9
0
0
1
0
0
0
0
246
0
1
0
0
2
1
0
0
0
1
8
0
15
0
1
66
0
0
1
0
0
0
0
0
0
0
0
1
0
14
1
0
1
0
0
0
0
376
0
0
0
0
1
7
0
0
0
0
16
0
22
0
2
171
1
0
4
0
0
0
0
0
0
0
1
0
0
5
0
0
0
0
0
3
2
207
0
0
0
1
2
2
0
0
1
0
18
0
9
0
1
113
0
0
0
0
0
0
0
1
0
0
0
1
0
10
2
3
0
0
0
2
0
236
0
0
1
3
0
3
0
0
0
1
16
0
9
0
4
79
0
0
2
0
0
0
0
0
0
0
1
0
0
16
4
0
0
0
2
4
0
325
0
0
0
1
0
5
0
5
0
1
8
0
9
0
2
93
0
0
0
0
0
0
1
0
1
1
1
0
0
16
2
0
0
2
1
0
2
309
0
0
1
0
2
2
0
0
0
0
19
2
20
0
1
80
0
1
1
0
1
1
0
1
0
1
1
0
1
18
0
0
0
0
2
0
0
331
0
0
2
0
1
5
1
0
0
0
14
0
10
2
2
224
0
0
2
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
1
0
12
5
0
166
Monophasic,
4,5,12:b
I 4,5,12:b:I 4,5,12:i:I 4,12:i:Monophasic, I
4,12,i
I 4,12,:H to
rough to type
Serotype
I 6,7:r:I 6,8:d:I 9,12:-:1,5
I 9,12:lv:I 47:Z4Z23
II rough:b:e,n,
x,z15
II 21:z10:{z6}
II 50:b:z6
IIIa
13,22:z4z23:IIIa 53:z4,z23:IIIb 53:z52:z53
IIIb 61:-:1,5
IIIb
rough:z10:z35
IV 16:z4,z32:IV 44:z36,(z38):IV 48:g,z51:(formerly marina)
Ibadan
Indiana
Infantis
Inverness
Irumu
Istanbul
Jangwani
Java
Javiana
Johannesburg
Kentucky
Kiambu
Kingabwa
Kintambo
Kottbus
Kua
Limete
Lindern
Litchfield
Livingstone
Lome
Lomalinda
Lomita
0
0
0
0
0
0
42
13
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
0
0
1
14
46
2
0
0
0
0
0
0
0
0
1
0
1999
2000
2001
2002
2003
2004
2005
2006
2007
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
0
0
2
0
0
3
0
0
3
0
0
2
0
0
3
0
0
2
0
0
2
0
0
0
2
1
5
0
2
51
1
0
0
0
41
27
6
4
1
0
0
0
0
0
0
10
0
0
0
0
0
0
38
0
0
0
0
35
24
3
1
2
0
0
0
0
0
0
9
0
0
2
0
0
0
35
0
0
0
0
24
17
3
3
2
1
1
2
1
0
0
9
1
0
0
0
0
2
30
2
0
0
1
7
19
1
1
5
0
0
0
1
0
0
7
1
0
9
0
0
0
130
0
1
0
0
1
263
0
2
1
0
0
0
0
0
0
13
1
0
0
0
0
0
96
1
0
0
0
0
24
0
1
1
0
0
1
0
0
0
8
0
0
0
1
0
1
35
0
0
0
0
9
16
2
2
2
0
0
1
0
0
1
5
0
0
1
0
2
0
30
1
0
0
0
8
11
3
0
3
0
1
0
0
1
0
5
0
0
0
0
0
0
45
0
0
1
1
3
20
2
3
0
0
0
0
0
0
0
16
0
0
0
0
167
London
Manhattan
Marina
Matadi
Mbandaka
Meleagridis
Miami
Serotype
Mikawasim
Minnesota
Mississippi
Molade
Monschaui
Montevideo
Morotai
Muenchen
Muenster
Nagoya
Napoli
New-brunswick
Newington
Newport
Nima
Norwich
Oakland
Offa
Ohio
Onderstepoort
Oranienberg
Oranienberg var
14+
Orientalis
Orion
Oslo
Panama
Paratyphi a
Paratyphi b
Paratyphi c
Parera
Pensacola
Poano
Pomona
Poona
Putten
Reading
Richmond
Rissen
Rubislaw
San-diego
Saint-paul
Saphra
Schwarzengrund
3
4
2
0
10
0
4
1999
0
0
3
0
0
56
0
36
1
0
0
1
3
59
0
4
0
0
3
0
21
0
0
0
5
3
1
1
0
0
0
1
0
19
1
2
0
0
0
0
21
0
7
4
8
3
0
7
0
2
0
3
3
0
1
35
0
32
3
0
0
1
0
85
1
6
0
0
0
0
24
0
1
3
0
0
0
16
0
42
2
0
1
0
0
121
2
2
0
0
6
0
28
0
0
0
0
0
2
21
0
32
1
0
0
0
0
121
1
2
0
0
2
0
37
0
0
0
1
1
1
27
0
45
1
1
0
0
1
151
0
3
1
0
1
1
30
0
1
2
5
0
0
48
0
34
1
0
1
0
0
94
0
5
0
0
7
3
0
1
41
0
32
5
1
0
0
0
68
0
0
0
23
0
26
0
0
0
27
0
4
2
0
0
24
3
1
2006
0
3
4
0
2
27
0
30
3
0
0
0
0
131
0
2
0
0
5
0
33
2
0
0
1
2
11
1
0
0
0
0
0
16
0
6
0
1
1
3
28
0
3
0
0
1
9
2
0
1
0
0
0
0
12
0
4
0
2
1
1
22
0
1
0
1
2
11
9
1
0
0
0
0
0
6
0
5
1
1
1
5
37
1
5
0
0
2
3
18
5
0
0
0
1
3
7
0
5
0
2
1
4
27
0
9
1
0
0
5
4
18
0
1
1
0
3
12
0
7
0
0
3
11
50
0
6
0
0
1
8
7
8
2
0
1
0
6
7
1
4
1
1
1
4
28
1
11
0
0
1
11
14
11
0
0
0
0
1
9
0
0
1
1
0
9
15
0
10
2000
0
4
3
0
7
0
4
2001
1
3
2
0
5
0
2
2002
3
1
3
2
6
2
4
2003
168
4
4
2
0
6
0
1
2004
1
2
0
0
9
1
2
2005
1
11
0
0
16
1
0
2007
0
2
4
0
1
42
0
95
3
0
0
0
0
131
0
3
0
0
4
0
38
1
0
0
0
9
11
18
0
0
0
0
0
13
0
8
1
0
1
14
31
0
6
Senftenberg
Shubra
Simi
Singapore
Soahamina
Stanley
Stanleyville
Serotype
Sundsvall
Takoradi
Tallahassee
Telelkebir
Tennessee
Thompson
Tilene
Tucson
Typhimurium
Typhimurium
var.
Copenhagen
Typhimurium
var. O:5
Uganda
Urbana
Utah
Virchow
Wandsworth
Wangata
Wassenaar
Waycross
Weltevreden
Weston
Worthington
Monophasic,
other
Non-motile
Other
Too rough to
type
Untyped
TOTAL
13
0
0
0
0
12
1
1999
0
0
0
1
2
30
0
0
354
0
9
0
0
2
0
5
0
0
0
0
2
0
36
0
0
350
0
12
0
1
0
0
4
0
2001
0
1
0
0
2
24
0
0
285
0
0
0
0
0
0
0
0
0
7
5
7
0
8
0
0
0
0
3
0
1
0
8
2
0
2
0
2
1
0
0
0
1
0
15
2
0
4
1
1
0
0
2
0
0
0
5
2
0
3
0
0
2
0
1
0
0
0
3
0
1
11
0
0
0
2
3
0
1
0
2
4
0
8
0
0
0
0
4
0
5
2
2
2
0
4
0
0
0
0
3
0
0
51
4
1
0
4
0
0
0
0
3
0
4
60
2
2
0
2
2
0
0
0
2
0
1
4
0
0
0
0
0
0
0
0
0
0
3
0
0
24
0
0
4
0
13
7
6
3
16
1
2
16
1
152
1600
123
1502
156
1383
271
1770
228
1995
117
1612
272
1837
101
1622
77
1966
2000
8
0
0
0
0
9
0
1
0
0
0
4
24
0
0
314
0
2
0
0
0
0
12
0
2003
0
1
0
2
8
30
0
0
373
0
1
0
0
1
0
10
0
2004
0
0
0
2
5
35
1
0
274
0
10
1
0
0
2
15
2
2005
0
0
0
1
6
33
0
0
376
2
4
0
0
1
0
11
0
2006
0
0
1
1
18
24
0
0
303
0
6
1
0
0
0
11
1
2007
0
1
0
1
26
20
0
1
367
3
2002
Table 12. Twelve Serotypes and exposure location, 2007
Serotype
TOTAL
Exposed in Illinois
Exposed in another state
Exposed outside of
the U.S.
Agona
34
#
%
#
%
#
%
20
83
0
0
4
17
169
Braenderup
19
15
94
0
0
1
6
Enteritidis
331
191
75
8
3
54
21
Heidelberg
224
218
97
6
3
1
0.4
Infantis
45
26
90
1
3
2
7
Montevideo
42
40
93
1
2
2
5
Muenchen
95
73
94
4
5
1
1
Newport
131
101
94
5
5
1
1
Oranienberg
38
22
85
0
0
4
15
Paratyphi A
11
0
0
0
0
10
100
Paratyphi B
18
11
92
1
8
0
0
Typhimurium
367
243
93
8
170
3
9
3
Sexually Transmitted Diseases
Included in this section are three diseases - chlamydia, gonorrhea and syphilis transmitted primarily or exclusively through sexual contact and reportable under Illinois
statutes and administrative rules. Other diseases not included in this section (such as
herpes and human papillomavirus) may be transmitted sexually. HIV/AIDS is discussed
in a separate section.
The control of sexually transmitted diseases (STDs) is an important strategy for
the prevention of HIV. The inflammation and lesions associated with STDs increase an
individual’s risk for acquisition of HIV, as well as the ability to transmit HIV to others.
Chlamydia
Background
Chlamydia trachomatis infection is a significant cause of genitourinary
complications, especially in women. Early symptoms of cervicitis or urethritis are mild;
asymptomatic infection is common in both women and men. If left untreated, chlamydia
infection can lead to pelvic inflammatory disease in women. It may cause severe
fallopian tube inflammation and damage, even though symptoms may be mild. Due to
the insidious nature of the infection, C. trachomatis is a major cause of long-term
sequelae such as tubal infertility and ectopic pregnancy and can cause premature
rupture of membranes in pregnant women. Chlamydia also can cause ophthalmia and
pneumonia in newborns exposed to it during birth.
Chlamydia is reportable in all but one state. During 2007, 1,108,374 chlamydia
infections were reported to the CDC, making chlamydia the most commonly reported
notifiable disease in the United States. However, national data are incomplete because
the majority of testing currently is conducted in females.
Federal and state funding for chlamydia is targeted at providing screening
programs in STD clinics, women’s health programs (such as family planning and
prenatal clinics), and in adult and juvenile correctional centers.
Case definition
The case definition is isolation of C. trachomatis by culture, or demonstration of
C. trachomatis in a clinical specimen by detection of antigen or nucleic acid.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – 55,470; the overall incidence rate was
447 per 100,000 population. The number of cases increased by 69 percent from
1998 to 2007 (Figure 81).
• Age - Adolescents and young adults (ages 15 to 24) represented the majority of
cases. Adolescents aged 15 to 19 years accounted for 34 percent of reported
chlamydia cases in 2007 (Figure 82). The average age of persons reported with
chlamydia was 23 years.
• Gender - Most reported cases were in women (75 percent) due to screening efforts
that target this group. The female-to-male ratio of reported cases was 3.0: 1.0.
171
•
•
Race/ethnicity - The racial distribution of cases was 55 percent non-hispanic African
American, 20 percent non-hispanic white, 2 percent non-hispanic Asian/Pacific
Islander and Native American and 13 percent other or unknown race. Eleven
percent were Hispanic.
Geographic distribution - Chlamydia is geographically distributed throughout the
state. Cases were reported from all 102 counties. The five counties with the highest
incidence rates per 100,000 were Pope (997), St. Clair (904), Peoria (878),
Alexander (876) and Jackson (835).
Summary
Chlamydia is the most commonly reported sexually transmitted disease in Illinois.
Cases were reported from all counties in Illinois during 2007. Adolescents and young
adults had the highest incidence rates. Reasons for the increase in cases from 1993 to
2007 include increased testing, improved surveillance, and the use of more sensitive
diagnostic tests.
Number of cases
Figure 81. Chlamydia Cases in Illinois, 2002-2007
60000
50000
55470
53586
55000
48101
50559
48294
47185
45000
40000
2002
2003
2004
2005
2006
2007
Year
Incidence pepr
100,000
Figure 82. Age Distribution of Chlamydia Cases in Illinois, 2007
2500
2000
1500
1000
500
0
0-4
5-9 yr
1 0-14
yr
15-19
yr
20-2 4
yr
25 -29
yr
30-34
yr
Y ear
172
35-39
yr
40 -44
yr
45-54
yr
55-64
yr
65 +
Gonorrhea
Background
Gonorrhea is a bacterial infection caused by Neisseria gonorrhoeae.
Uncomplicated urogenital infection may progress, without treatment, to complications
such as infertility, pelvic inflammatory disease (PID) and disseminated infection.
Resultant scarring of fallopian tubes may result in ectopic pregnancy. Women are more
likely than men to suffer complications from gonorrhea infection because early
symptoms are often not present or not recognized in females. Infants born to infected
mothers may develop gonococcal ophthalmia, which is potentially blinding, or sepsis,
arthritis or meningitis. The United States recorded 355,991 cases of gonorrhea in 2007.
Currently recommended therapies for gonorrhea are highly effective, although
antimicrobial drug resistance has been a problem. Gonococcal susceptibility to some
currently recommended drugs is gradually declining, and active surveillance is required
to monitor resistance and to ensure the effectiveness of therapy.
Case definition
Isolation of typical gram-negative, oxidase positive diplococci (presumptive
Neisseria gonorrhoeae) from a clinical specimen; demonstration of N. gonorrhoeae in a
clinical specimen by detection of antigen or nucleic acid; or observation of gramnegative intracellular diplococci in a urethral smear obtained from a male urethral or
female endocervical smear.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – 20,813; case rate was 168 per
100,000 population. Reported cases in 2007 were slightly higher than the number
reported in 2006 (Figure 83). Gonorrhea is the second most commonly reported
STD in Illinois.
• Age - Adolescents and young adults are at greatest risk for gonorrhea infection.
Persons aged 15 to 24 accounted for 63 percent of reported cases in 2007 (Figure
84).
• Race/ethnicity - Illinois minorities are disproportionately affected by gonorrhea. The
reported cases were 76 percent non-hispanic African American, 12 percent nonhispanic white, less than less than 1 percent non-hispanic Asian/Pacific Islander and
9 percent other or unknown race. Three percent were Hispanic.
• Geographic distribution - At least one case of gonorrhea was reported in each of 90
Illinois counties. The five counties with the highest incidence rate in 2007 were
Peoria (493), St. Clair (413), Alexander (386), Vermilion (357) and Macon (353).
Summary
Gonorrhea is the second most commonly reported sexually transmitted disease
after chlamydia in Illinois. In 2007, 63 percent of gonorrhea cases in Illinois were in
those 15 to 24 years of age.
173
Number of cases
Figure 83. Gonorrhea Cases in Illinois, 2002-2007
30000
24026
21817
20597
20019
20813
20186
20000
10000
0
2002
2003
2004
2005
2006
2007
Year
Incidence
Figure 84. Age Distribution of Gonorrhea Cases in Illinois, 2007
8 000
6 000
4 000
2 000
0
0 -4
5-9 yr
10-14
yr
15- 19
yr
20-24
yr
25-29
yr
30- 34
yr
Ye ar
174
3 5-39
yr
40-44
yr
45- 54
yr
5 5-64
yr
65 + yr
Syphilis
Background
Syphilis is a systemic disease caused by the spirochete Treponema pallidum.
The infection is definitively diagnosed through microscopic examination of lesion
exudates and presumptively through serologic testing. Without treatment, syphilis
infection progresses through four stages: primary, characterized by a painless ulcer at
the point at which the organism entered the body (genitals, mouth, anus); secondary,
characterized by lesions, rashes, hair loss, lymphadenopathy and/or flu-like symptoms;
latent with no signs or symptoms; and late symptomatic, in the form of neurosyphilis
(with neurologic damage) and tertiary (cardiovascular or gummatous disease).
The open lesions of syphilis are infectious to sex partners. Syphilis during
pregnancy can lead to a congenital form of the disease that may result in stillbirth or
severe illness and lifelong debilitating consequences for the infant. Increases in syphilis
often are associated with poverty, limited availability of health services and the
exchange of sex for drugs or money. Syphilis outbreaks are often a precursor of HIV
increases in affected populations because the lesions caused by syphilis increase the
likelihood of both acquisition and transmission of HIV. Without treatment, approximately
10 percent of persons with syphilis will develop neurosyphilis, but in persons co-infected
with HIV, 25 percent may develop neurosyphilis.
“Early syphilis” refers to syphilis infection of less than one year duration and
progresses through primary, secondary and early latent. Public health disease
intervention efforts emphasize control of early syphilis because persons with this stage
of the disease are most likely to have been infectious within the past year. Many
individuals do not notice or recognize the symptoms of syphilis, so screening for latent
disease and partner notification and referral are important components of control efforts.
Congenital syphilis occurs when the syphilis organism is transmitted from a
pregnant woman to her fetus. Untreated syphilis during pregnancy can result in
stillbirth, neonatal death or infant disorders such as deafness, bone deformities, and
neurologic impairment. In 2007, the congenital syphilis rate increased from 2006.
Significant public health resources must be devoted to the control of syphilis.
Untreated syphilis can result in neurological or cardiovascular complications. It also can
be transmitted to a fetus from an infected woman during pregnancy, which results in
congenital syphilis.
The CDC recorded 11,466 primary and secondary syphilis cases in the United
States in 2007. The rate of infection was 3.8 per 100,000 population. In 2007, a total of
430 cases of congenital syphilis were reported.
Case definition
Syphilis is a complex disease with a highly variable clinical course. The following
case definitions are used for surveillance purposes for syphilis that has not progressed
to late symptomatic stages.
•
Primary. A clinically compatible case with one or more ulcers consistent with primary
syphilis and a reactive serologic test; or demonstration of T. pallidum in clinical
specimens by dark field microscopy, fluorescent antibody or equivalent methods.
175
•
•
Secondary. A clinically compatible case with a reactive nontreponemal test titer of >
1:4 (probable case), or demonstration of T. pallidum in clinical specimens by dark
field microscopy, fluorescent antibody or equivalent methods (confirmed case).
Latent. No clinical signs or symptoms of syphilis and the presence of one of the
following:
o No past diagnosis of syphilis, a reactive nontreponemal test and a reactive
treponemal test.
o A past history of syphilis therapy and a current nontreponemal test titer
demonstrating fourfold or greater increase from the last nontreponemal test
titer.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 - Eleven congenital cases and 464
primary or secondary cases (Figure 85). Primary and secondary cases increased 24
percent between 2003 and 2007. The incidence rate for 2007 was 3.7 per 100,000
population for primary and secondary syphilis and 6.1 per 100,000 live births for
congenital syphilis. Note: CDC summaries show 10 congenital syphilis cases
reported from Illinois in 2007. We will use 11 cases in this report.
• Age - The average age of persons diagnosed with primary and secondary syphilis is
36 years. Adults aged 30 years and older accounted for 69 percent of primary and
secondary syphilis cases (Figure 86).
• Gender - Ninety-one percent of cases were male.
• Race/ethnicity - Minorities in Illinois are disproportionately affected by syphilis,
especially African Americans, who accounted for 64 percent of the congenital
syphilis cases. The proportion of primary and secondary syphilis cases by race were
non-hispanic white (36 percent), non-hispanic African American (42 percent) and
other or unknown races (7 percent). Fifteen percent were Hispanic.
• Geographic distribution - Syphilis is more prevalent in urban populations. The
disease has become progressively concentrated geographically. Cases of primary
and secondary syphilis were reported from 22 counties. The five highest incidence
rates per 100,000 population in counties with at least three cases were St. Clair
(7.4), Cook (7.3), Mclean (2.7), Peoria (2.2) and Dupage (1.3).
• Clinical presentation – During 2007, there were 25 cases of reported neurosyphilis;
(88 percent) of the 2007 cases were in men. Of the 22 males, 32 percent were
MSM.
Summary
Primary and secondary syphilis cases increased by 24 percent in 2007 compared
to 2003. During 2007, African American females were disproportionately affected by
syphilis.
176
Number of cases
Figure 85. Syphilis Cases in Illinois, 2002-2007
600
525
479
400
200
464
431
386
374
Primary and Secondary
Congenital
41
21
25
25
16
11
2002
2003
2004
2005
2006
2007
0
Year
Number of cases
Figure 86 . Age Distribution of Syphilis Cases in Illinois, 2007
200
150
100
50
0
0-4
5-9 yr
10-19 yr
20 -29 yr
30-39 yr
Y ear
177
40-54 yr
55- 64 y r
65+ yr
Shigellosis
Background
Shigellosis is an acute bacterial disease of humans and non-human primates
caused by four species or serogroups of Shigella: S. dysenteriae (group A), S. flexneri
(group B), S. boydii (group C) and S. sonnei (group D). The infectious dose is low; as
few as 10 to 100 bacteria can cause infection. Transmission is via direct or indirect
fecal-oral routes. Outbreaks in day care centers are not uncommon and Shigella can be
transmitted through unchlorinated wading pools, interactive water fountains, food items
such as parsley and bean dip and between men who have sex with men. The
incubation period is usually one to three days. Symptoms of the disease are watery or
bloody diarrhea with fever and sometimes vomiting or tenesmus. Mild and
asymptomatic infections can occur. Duration of illness is usually from four to seven
days. Shigella can be shed in stool for four weeks. Disease caused by Shigella
dysenteriae type 1 is the most severe and can cause hemolytic uremic syndrome (HUS)
due to a toxin similar to that produced by E. coli O157:H7. Antimotility drugs are
contraindicated. Antimicrobial therapy can limit the clinical course and duration of fecal
excretion of Shigella. Shigella can develop antimicrobial resistance quickly.
The subgroups, serotypes and subtypes of Shigella are:
Group A: Shigella dysenteriae
15 serotypes (type 1 produces Shiga toxin)
Group B: Shigella flexneri
8 serotypes and 9 subtypes
Group C: Shigella boydii
19 serotypes
Group D: Shigella sonnei
1 serotype
In a study in Washington staste, risk factors for sporadic Shigella infections
included exposure to aquatic recreation and consumption of raw herbs.
Of the 10 diseases/syndromes (caused by Campylobacter, Cryptosporidium,
Cyclospora, HUS, E. coli O157:H7, Listeria monocytogenes, Salmonella, Shigella,
Vibrio and Yersinia enterocolitica) under active surveillance in the federal FoodNet sites,
Shigella comprised 17 percent of the reported infections in 2007. The incidence rate
overall was 6.2 per 100,000 for shigellosis and ranged from 0.9 to 17 at the 10 FoodNet
sites. Ninety-five percent were serotyped. Eighty-one percent of these cases were due
to S. sonnei and 13 percent were S. flexneri.
In 2007, 19,758 Shigella cases were reported to CDC. S. sonnei accounts for
greater than 75 percent of shigellosis cases in the United States.
Multi-community outbreaks of shigellosis require extensive time and effort on the
part of public health. Because of the low infectious dose, shigellosis spreads quickly
between people when breaches in hand washing or sanitation occur. Propagation of
shigellosis is increased because of the difficulty in maintaining handwashing and
sanitation in day care centers, high proportion of mild or asymptomatic Shigella
infections and frequent contact between children who attend multiple day care centers.
Interventions include alerting the media to the outbreak, direct communication with day
care centers and the medical community, and promoting control strategies such as
supervised handwashing and exclusion of symptomatic children from day care.
However, strict exclusion policies of infected but asymptomatic children can lead to
spread of an outbreak if excluded day care attendees are then placed in alternative
child care settings.
178
Case definition
The case definition for a confirmed case of shigellosis in Illinois is a case from
which Shigella is isolated from a clinical specimen. The case definition for a probable
case is a person who has a clinically compatible illness that is epidemiologically linked
to a confirmed case, but is not laboratory confirmed.
Descriptive epidemiology
• Number of reported cases in Illinois in 2007 - 781 (five-year median = 720; see
Figure 87). Overall annual incidence rate was 6 per 100,000. Of the cases, 761
were confirmed and 20 were probable. The number of shigellosis cases
increased slightly in 2007 as compared to 2006.
• Age - Mean age = 20 (Figure 88). By age group, annual incidence rates per
100,000 were: younger than one year old (nine); 1 to 4 years of age (27); 5 to 9
years of age (19); 10 to 19 years of age (five); 20 to 29 years of age, (six); 30 to
59 years of age (three); and 60 and older (two).
• Gender – Fifty-four percent were female.
• Race/ethnicity – Forty-eight percent were white, 40 percent were African
American, and 12 percent were other races; Twenty percent were Hispanic.
There were significantly higher proportions of Hispanics with shigellosis
compared to their representation in the Illinois population (12 percent).
• Geographic distribution – For 2007, counties with the highest incidence per
100,000 were Union (153), Rock Island (88), Pulaski (54), Peoria (35) and
Morgan (25).
• Clinical syndrome – Symptoms reported included diarrhea (98 percent), fever (72
percent) and vomiting (46 percent).
• Outcome – Twenty-six percent of cases were hospitalized. No fatalities were
reported.
• Seasonal variation - Shigellosis cases occurred in all months of the year with a
peak in the fall (Figure 89).
• Serotypes - Ninety-seven percent of isolates were serotyped in 2007. The most
common species was S. sonnei (89 percent of typed isolates), followed by S.
flexneri (11 percent). S. boydii made up less than one percent of typed isolates.
The boydii serotypes found in Illinois were 2, 4 and 19 (Table 13). No S.
dysenteriae were identified (Table 14). The three most common S. flexneri
serotypes were 2a (19 cases), 1b (15 cases), and two (11 cases) (Table 15). S.
sonnei does not have subtypes, but there were 675 S. sonnei cases reported.
• Reporter – Thirty-eight percent were reported by infection control professionals
and 55 percent by laboratories.
• Risk factors
o Twenty-five cases acquired their infection in another country.
o Seven cases acquired infection in another state.
o Eighteen of 617 (3 percent) reported swimming in non-chlorinated water,
and 34 of 612 (5 percent) swam in chlorinated water.
o Fifty-seven cases attended day care and 32 attended a residential facility.
179
•
•
•
o Seventeen percent (105 of 629 cases) reported contact with someone
attending a residential facility. Twenty-one percent (131 of 628 cases)
reported contact with someone in a day care facility.
o Twenty-eight cases reported drinking water from a well.
Sensitive occupations – Cases were employed in the following sensitive
occupations: food service (four), day care (five), health care (nine), residential
facility (six), and other sensitive occupations (13).
Foodborne outbreaks – There were no foodborne outbreaks of shigellosis in
2007.
Person-to-person outbreaks – Ten person-to-person outbreaks were reported
(See non-foodborne non-waterborne outbreak section).
Summary
There was an increase in Shigella cases from 2006 to 2007. The incidence rate
for 2007 of 6 per 100,000 was the same as that reported by the CDC’s FoodNet sites.
The proportion who were Hispanic was higher than their representation in the Illinois
population. The mean age of cases was 20 years. Ninety-seven percent of isolates
were serotyped in Illinois as compared to 95 percent in the CDC FoodNet sites. S.
sonnei was the most common serotype found in Illinois, which is the same as the most
common serotype identified in CDC’s FoodNet sites. Isolates of Shigella are required to
be submitted to the Departments laboratories for speciation and/or serotyping (if this
cannot be done by the clinical laboratory).
Suggested readings
Denno, D.M., et. al. Tri-county comprehensive assessment of risk factors for
sporadic reportable bacterial enteric infection in children. JID 2009;199:467-476.
Centers for Disease Control and Prevention. FoodNet 2007 Surveillance Report.
Atlanta: U.S. Department of Health and Human Services, 2009.
Number of cases
Figure 87. Shigella Cases in Illinois, 2002-2007
1500
1105
1006
1000
720
402
500
781
409
0
2002
2003
2004
2005
Year
180
2006
2007
30
25
20
15
10
5
0
Male
Female
<1 yr
1-4 yr
5-9 yr
10- 19 y r 20-29 yr 30- 39 y r 40-49 yr 5 0-59 yr
>59 yr
Age category
Figure 89. Shigella Cases in Illinois by Month, 2007
Number of cases
Incidence
Figure 88. Age Distribution of Shigella Cases in Illinois, 2007
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
181
Aug
Sep
Oct
Nov
Dec
Table 13. Frequency of Shigella boydii in Illinois, 2000-2007
Type
2000 2001 2002 2003 2004 2005 2006 2007
boydii, unknown
0
0
0
0
0
0
0
0
boydii 1
0
2
0
0
0
0
1
0
boydii 2
4
3
1
5
1
1
1
2
boydii 3
0
0
1
0
0
0
0
0
boydii 4
2
0
2
2
1
1
0
2
boydii 5
1
0
0
0
0
0
0
0
boydii 8
0
0
0
0
2
0
0
0
boydii 10
0
0
0
0
0
0
0
0
boydii 11
1
0
0
0
0
0
0
0
boydii 12
0
0
0
0
0
0
1
0
boydii 13
1
0
0
0
0
0
0
0
boydii 14
2
1
2
1
0
0
0
0
boydii 18
1
0
0
0
1
0
0
0
boydii 19
0
0
0
0
0
0
0
1
boydii 20
0
0
0
0
1
0
0
0
12
6
3
8
2
3
5
TOTAL boydii
Source: Illinois Department of Public Health
Table 14. Frequency of Shigella dysenteriae in Illinois, 2000-2007
Type
2000 2001 2002 2003 2004 2005 2006 2007
dysenteriae,
unknown
2
0
0
1
1
0
1
0
dysenteriae 1
0
0
0
0
1
0
0
0
dysenteriae 2
0
0
0
2
0
0
1
0
dysenteriae 3
0
0
1
0
1
0
1
0
dysenteriae 4
0
0
1
0
0
3
0
0
dysenteriae 9
0
0
0
0
0
0
0
0
dysenteriae 12
0
0
0
0
0
0
0
0
TOTAL
dysenteriae
2
0
2
3
3
3
3
0
182
Source: Illinois Department of Public Health
Table 15. Frequency of Shigella flexneri subtypes in Illinois, 2000-2007
Type
flexneri, unknown
2000 2001 2002 2003 2004 2005 2006 2007
31
24
14
15
18
11
21
6
flexneri 1
3
5
8
9
15
11
13
2
flexneri 1A
0
0
0
0
0
0
0
0
flexneri 1B
0
0
0
0
0
0
1
15
49
23
36
33
21
29
23
11
flexneri 2A
0
0
0
1
2
0
0
19
flexneri 2A
(11:3,4)
0
0
0
0
0
0
0
4
flexneri 2B
0
0
1
0
0
0
0
1
27
14
7
29
27
14
14
6
flexneri 3A
0
0
0
0
1
0
3
6
flexneri 3B
0
0
0
0
0
0
1
0
10
11
23
11
13
7
11
2
flexneri 4A
1
0
0
1
0
0
0
8
flexneri 4B
0
0
0
0
0
0
0
0
flexneri 5
0
0
0
0
0
0
0
0
flexneri 5A
0
0
0
0
0
0
0
0
flexneri 6
8
9
8
7
6
0
3
1
flexneri X variant
0
0
1
1
1
2
0
0
flexneri Y variant
1
3
1
0
3
5
2
0
130
89
99
107
107
79
92
81
flexneri 2
flexneri 3
flexneri 4
TOTAL flexneri
Source: Illinois Department of Public Health
183
Staphylococcus aureus, Intermediate or High Level Vancomycin
Resistance
Background
Staphylococcus aureus causes both community and health care associated
infections in persons. The National Committee for Clinical Laboratory Standards
(NCCLS) defines staphylococci requiring concentrations of vancomycin of < 4 ug/mL for
growth inhibition as susceptible to vancomycin. Those requiring concentrations of eight
to 16 ug/mL as intermediate and those requiring concentrations of at least 32 ug/mL as
resistant. S. aureus with reduced vancomycin susceptibility (SA-RVS) includes all S.
aureus isolates with MICS of vancomycin of at least four ug/mL.
Three cases of SA-RVS have been identified in Illinois, two in 1999 and one in
2000.
Case definition
A case of S. aureus, intermediate or high level vancomycin resistance is defined
as S. aureus isolated from infected humans with an MIC of vancomycin of at least four
ug/mL.
Descriptive epidemiology
No cases were reported in 2007.
Summary
No cases were reported in 2007 in Illinois.
184
Streptococcus pyogenes, Group A (Invasive Disease)
Background
The spectrum of disease caused by group A streptococci (GAS) is diverse and
includes pharyngitis and pyoderma, severe invasive infections, post-streptococcal acute
rheumatic fever and acute glomerulonephritis. Invasive GAS may present as any of
several clinical syndromes including pneumonia, bacteremia in association with
cutaneous infection (cellulitis, erysipelas or infection of a surgical or nonsurgical
wound), deep soft tissue infection (myositis or necrotizing fasciitis), meningitis,
peritonitis, osteomyelitis, septic arthritis, postpartum sepsis (puerperal fever), neonatal
sepsis and non-focal bacteremia. Two types of invasive GAS are streptococcal toxic
shock syndrome (STSS) and necrotizing fasciitis. The symptoms of STSS include fever,
myalgia, vomiting, diarrhea, confusion, soft tissue swelling, renal dysfunction,
respiratory distress and shock. Necrotizing fasciitis is a deep infection of subcutaneous
tissue that results in destruction of fat and fascia and often leads to systemic illness.
Risk factors for necrotizing fasciitis include injection drug use, obesity and diabetes
mellitus.
Transmission of GAS occurs by direct contact with patients or carriers, or by
inhalation of large respiratory droplets. Approximately 5 percent of the population may
be asymptomatic carriers, but these individuals are less likely to transmit the organism
than symptomatic persons. Predisposing risk factors for invasive GAS include older
age, injection drug use, human immunodeficiency infection, diabetes, cancer, alcohol
abuse, varicella, penetrating injuries, surgical procedures, childbirth, blunt trauma, and
muscle strain. Household members should monitor themselves for signs and symptoms
for 30 days after exposure.
During 2007, 1,166 cases of invasive GAS were reported from the Active
Bacterial Core Surveillance site projects in 10 states. Incidence was highest in adults
older than 65 years of age (9.9 cases per 100,000) and children younger than one year
of age (6.4 cases per 100,000). STSS accounted for 5 percent, and necrotizing fasciitis
accounted for 6 percent of cases. The overall case fatality rate was 0.44 per 100,000.
In routine surveillance, 5, 294 cases of invasive GAS were reported to CDC and
132 cases of streptococcal TSS.
Case definition
The case definition of invasive GAS disease in Illinois is the isolation of group A
Streptococcus pyogenes by culture from a normally sterile site.
Descriptive epidemiology
• Number of reported cases in Illinois in 2007 – There were 326 invasive GAS cases
(five-year median = 326) reported. Of these 326, seven were necrotizing fasciitis
and 33 streptococcal toxic-shock syndrome cases (see Figure 90). All but one case
was confirmed. The incidence rate for 2007 was 2.6 per 100,000 population.
• Age - Mean age was 50 years (Figure 91). By age group, the highest incidence per
100,000 occurred in those older than 79 years of age (15 per 100,000 in that age
group), followed by those 70 to 79 years of age (six per 100,000) and 60 to 69
years of age (six per 100,000). Twenty-two cases were residents of residential
institutions.
185
•
•
•
•
•
•
Gender – Fifty percent were male.
Race/ethnicity - Cases were 68 percent white, 26 percent African American and 6
percent other races; 14 percent occurred among Hispanics.
Geographic distribution – Forty-five percent were residents of Cook County. Cases
resided in 47 counties.
Seasonal variation - An increase in cases occurred from January to April (Figure
92).
Outcome – Ninety-four percent were hospitalized. The overall case fatality rate was
7 percent.
Reporting – Eighy-two percent were reported by health care providers and 17
percent were reported by laboratories.
Summary
The number of reported invasive GAS cases in 2007 was the same as in 2006.
The highest incidence was in those older than 79 years of age, followed by those 60 to
79 years of age. Illinois had the second highest number of streptococcal toxic shock
cases reported in the United States.
Number of cases
Figure 90. Invasive GAS and Streptococcal TSS Cases in Illinois, 2002-2007
500
400
300
200
100
0
417
326
342
284
2002
2003
2004
326
2005
326
2006
2007
Year
Incidence
Figure 91. Invasive GAS and Streptococcal TSS Cases by Age in Illinois,
2007
20
15
10
5
0
0-4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
40-49 yr
Age Group
186
50-59 yr
60-69 yr
70-79 yr
80+
Number of cases
Figure 92. Invasive GAS and Streptococcal TSS Cases in Illinois by
Month, 2007
60
40
20
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month of Onset
187
Aug
Sep
Oct
Nov
Dec
S. pneumoniae
Background
S. pneumoniae is the most common cause of meningitis, community-acquired
pneumonia and bacteremia and acute otitis media. Pneumococci colonize the
nasopharynx of 15 percent to 60 percent of individuals; most remain asymptomatic.
Carriage is higher in children attending child care centers outside the home. The onset
of S. pneumoniae meningitis is usually sudden with high fever, lethargy and signs of
meningeal irritation. It is a sporadic disease in the elderly and in young infants.
In the ten states which are part of the Active Bacterial Core Surveillance, 4,012
cases were reported in 2007, 15 percent exhibited intermediate resistance to penicillin
and 10 percent were fully resistant.
The pneumococcal conjugate 7-valent vaccine (6B, 14, 18C, 19F, 23F, 9V, 4)
was licensed in the United States in February 2000 and can be used in children younger
than 2 years of age. The vaccine protects against the seven strains of pneumococcus
that cause 80 percent of the invasive disease among children in the United States.
Individuals at the extremes of age and in certain ethnic groups (African
American, American Indians and Alaskan natives) are disproportionately affected.
Males are at higher risk for S. pneumoniae. Other risk factors for invasive disease
include renal dysfunction, sickle cell disease, alcoholism, smoking, HIV, organ
transplantation and diabetes mellitus.
The Advisory Committee on Immunization Practices (ACIP) recommends that
vaccine be given to infants in a series of four injections (at 2, 4, 6 and 12-15 months of
age). The recommendation applies to all children younger than 24 months of age and to
children 24 to 59 months of age who are at higher risk of infection, including those with
certain illnesses (e.g., sickle cell anemia, cochlear implant, immunocompromising
condition, chronic heart or lung disease) and those who are Alaska natives, American
Indian or African American. The vaccine also can be considered for other children ages
24 to 59 months who are at increased risk, such as children in group day care, those
with frequent otitis media or those who are economically or socially disadvantaged.
In data for 2007 from the National Behavioral Risk Factor Surveillance system,
the percent of persons older than the age of 64 who had received at least one
pneumococcal vaccination was 60 percent.
The Healthy People 2010 objectives are to reduce invasive pneumococcal
disease to 46 per 100,000 in children younger than five years and to 42 per 100,000 in
adults aged 65 years or older. Since vaccine has been available incidence has declined.
Case definition
A case is defined as a person with clinically compatible symptoms and from
whom isolation of the organism from a normally sterile site has occurred. The case
numbers for this section were obtained using date of onset between January 1 and
December 31, 2007, not by year counted = 2007.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – 1,235 (five-year median = 1,012)
(See Figure 93). The incidence rate for 2007 was 9.9 per 100,000.
188
•
•
•
•
•
•
Age - Mean age of cases was 52 years (see Figure 94 for age distribution).
Incidence per 100,000 of reported S. pneumoniae in those less than four years of
age was 16.8 and for those aged 60 years and older was 29.
Gender - Forty-eight percent were female.
Race/ethnicity - Twenty-two percent were African American, 74 percent were white
and 4 percent were other races; 9 percent were Hispanic.
Seasonal peak – An increase in cases occurred in the winter and spring months
(Figure 95).
Outcome – Ninety percent of cases were hospitalized. Forty-eight cases were fatal.
Reporting - The majority of cases were reported by health care providers (84
percent).
Summary
Cases of S. pneumoniae were lower in the summer months. The mean age of
cases was 52 years.
Number of cases
Figure 93. S. pneumoniae Cases in Illinois, 2002-2007
1500
1000
1226
1012
823
1235
1196
936
500
0
2002
2003
2004
2005
2006
2007
Year
Incidence per 100,000
Figure 94 . S. pneumoniae Cases by Age in Illinois, 2007
40
30
20
10
0
< 4 yr
5-9 yr
10-19 yr
20-29 yr
30-39 yr
Age group
189
40-49 yr
50-59 yr
>59 yr
Number of cases
Figure 95 . S. pneumoniae Cases in Illinois by Month, 2007
200
150
100
50
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
190
Aug
Sep
Oct
Nov
Dec
Tetanus
Background
Tetanus is non-communicable. Clostridium tetani spores can be present in the
environment and enter the body through nonintact skin. Generalized tetanus presents
with trismus (lockjaw) followed by generalized rigidity caued by contractions of the
skeletal muscles. Forty-one cases were reported in the United States in 2007.
Case definition
A clinically compatible case as diagnosed by a health care professional.
Descriptive epidemiology
• Two cases were reported in Illinois in 2007.
• Description of cases
o The first case was a 31-year-old male from Chicago who had a
laceration when fixing a car antenna in July. He was treated for the
laceration but did not receive tetanus vaccination or TIG. It had
been 19 years since his last tetanus vaccination. In August he
presented with difficulty in opening his jaw and was treated with
TIG.
o The second case was a female 72-year-old suburban Cook County
resident. She had fallen in November and had a closed fracture and
was hospitalized for greater than 40 days. She had difficulty
opening her jaw in December and ended up on a ventilator.
191
Tickborne Diseases Found in Illinois
Ticks are the most common vector of vectorborne diseases in the United States.
Ticks are responsible for the following diseases in the United States: babesiosis,
Colorado tick fever, human granulocytic ehrlichiosis, human monocytic ehrlichiosis,
Lyme disease, Powassan encephalitis, relapsing fever, Rocky Mountain spotted fever
(RMSF), tick paralysis and tularemia.
Ticks usually attach around the head, neck and groin of the human host. The
rates of human infection with tick borne diseases are influenced by the prevalence of
vector tick species, the tick infection rate, the readiness of ticks to feed on humans, and
the prevalence of their usual animal hosts.
Five tickborne diseases are listed in Table 16 and in individual sections of this
document. In addition, at least one case of babesiosis was reported each year from
2003 thru 2007. According to CDC guidelines, any Illinois resident diagnosed with a tick
borne disease is counted in the state’s case count, even though he/she may have
reported tick exposures in another state. Case counts by year for 2002 through 2007 for
four of these infections that occur regularly in Illinois are shown in Figure 96.
Ehrlichiosis and RMSF cases numbers are increasing each year.
Number of
cases
Figure 96. Tickborne Disease Cases in Illinois, 2002-2007
200
100
47
127
87
71
149
110
12 5 6
5 1 9
14 5 12
11 1 7
26
2002
2003
2004
2005
2006
1
32
39
50
1
0
Year
Lyme
RMSF
192
Tularem ia
Ehrlichiosis
2007
Table 16. Tickborne Diseases Reported in Illinois Residents and which can be acquired
in Illinois
Add babesiosis
Disease
Organism
Tick vectors
Symptoms
Where found
Rocky Mountain
spotted fever
Rickettsia
rickettsii
Dermacentor
variabilis
(American dog
tick),
D. andersoni
(Rocky Mountain
wood tick)
fever, headache,
rash
throughout the
United States but
most common in
Southeast; entire
state of Illinois
Tularemia
Francisella
tularensis
Amblyomma
americanum
(lone star tick),
D. variabilis,
D. andersoni
ulcer at entry site,
enlarged lymph
node
throughout North
America; primarily
central and
southern Illinois
Lyme disease
Borrelia
burgdorferi
Ixodes scapularis
(deer tick)
fatigue, chills,
fever, erythema
migrans, enlarged
lymph nodes
primarily on the
West Coast, in
northeastern and
north central
United States;
primarily northern
Illinois
Human monocytic
ehrlichiosis
Ehrlichia
chaffeensis
A. americanum
fever, headache,
myalgia, vomiting
most common in
the southern
states; more
common in
southern Illinois
Human
granulocytic
ehrlichiosis
Anaplasma
phagocytophilum
I. scapularis
fever, headache,
myalgia, vomiting
most common in
upper Midwest
and Northeast; in
Illinois, unknown
distribution
193
Toxic Shock Syndrome (TSS) Due to Staphylococcus aureus
Background
Toxic shock syndrome is classified by clinical and laboratory evidence of fever,
rash, desquamation, hypotension and multiple organ failure caused by toxins produced
by Staphylococcus aureus. MRSA strains have caused TSS in other countries. Most
cases have been associated with strains of Staphylococcus aureus that produce a
special toxin.
In 2007, 92 cases were reported to CDC.
Case definition
The five clinical findings used to establish whether a case meets the case
definition for staphylococcal TSS are 1)
Fever - temperature greater than 102 F
2)
Rash
3)
Desquamation
4)
Hypotension
5)
Multisystem involvement (three or more of the following)
a.
Gastrointestinal - vomiting or diarrhea
b.
Muscular - myalgia or creatine phosphokinase (at least twice upper limit of
normal)
c.
Mucous membrane - vaginal, oropharyngeal or conjunctival hyperemia
d.
Renal - blood urea nitrogen or creatinine at least twice the upper limit of
normal or urinary sediment with pyuria in the absence of urinary tract
infection
e.
Hepatic - total bilirubin, alanine aminotransferase (ALT) or aspartate
aminotransferase (AST) at least twice the upper limit of normal for the lab
f.
Hematologic - platelets less than 100,000/mm3
g.
CNS - disorientation or alterations in consciousness without focal
neurologic signs when fever and hypotension are absent.
In addition, there should be negative results on the following tests (if done)
a.
Blood, throat or CSF cultures (blood cultures can be positive for S.
aureus)
b.
Rise in titer to Rocky Mountain spotted fever, leptospirosis or measles
The CDC case definition for a probable case is one with any four of the five
clinical findings above. A confirmed case is one with all five of the clinical findings,
including desquamation, unless the patient dies before desquamation can occur.
Descriptive epidemiology
•
•
•
•
Number of cases reported in Illinois in 2007 - Nine cases were reported (five-year
median = five cases). Six were confirmed, and three were probable.
Age - Ages ranged from 12 to 46.
Gender - All cases were female.
Seasonality – Cases had onsets ranging from January to December.
194
•
•
•
•
•
•
•
•
Race/ethnicity – All cases were white. None reported Hispanic ethnicity.
Geographic distribution - Cases were reported from five counties: Cook, Dupage,
Sangamon, Will and Winnebago.
Symptoms – Diarrhea (six of eight), fever (all eight), hypotension (seven of eight
cases), myalgia (seven of eight) and orthostatic dizziness (three of five cases),
vaginal discharge (one of five cases), desquamation (three of four cases) and
abdominal pain (two of five cases).
Laboratory findings - S. aureus was isolated from the vagina in seven cases, from
urine in two cases and from the trachea in one case. Seven cases were classified
as menstruation-associated and two did not have a source identified.
Treatment - All patients were hospitalized.
Outcome – One case was fatal.
Reporting – Seven cases were reported by infection control professionals, one from
a private physician and one from a laboratory at a hospital.
Past cases – Toxic shock syndrome cases due to S. aureus reported per year in
the state previously were 1998 (seven), 1999 (five), 2000 (three), 2001 (four), 2002
(five), 2003 (six), 2004 (six), 2005 (five) and 2006 (two).
Summary
Nine cases of staphylococcal toxic shock were reported in 2007 and seven
were considered to be associated with menstruation. Illinois and Minnesota each
reported nine cases, the most of any states.
195
Tuberculosis
Background
The Mycobacterium tuberculosis complex includes M. tuberculosis, M. africanum,
M. bovis and M. microti. Tubercle bacilli are transmitted by inhalation of airborne droplet
nuclei produced by persons with tuberculosis (TB) disease. Prolonged close contact
with cases may lead to latent TB infection (LTBI). Tuberculin skin sensitivity often
indicates LTBI (as noted by a positive skin test), which usually appears four to 12 weeks
after infection. LTBI is different from TB disease and is defined as a condition in which
TB bacteria are alive but inactive in the body. People with latent TB infection have no
symptoms and cannot spread TB to others. They usually have a positive skin test
reaction and may develop TB disease later in life if they do not receive treatment for
latent TB infection.
Approximately 90 to 95 percent of newly infected individuals have LTBI where
early lung lesions heal and leave no residual changes except small calcifications in the
pulmonary or tracheobronchial lymph nodes. In those patients whose infection
progresses to disease, early symptoms may include fatigue, fever, night sweats and
weight loss. In advanced disease, symptoms such as cough, chest pain, coughing up of
blood, and hoarseness may occur.
Several issues, such as patients’ immune status and immigration from areas
where TB is common, impact the incidence of TB in Illinois. The AIDS epidemic had a
profound effect on the number of TB cases in Illinois in the past. TB is a major
opportunistic infection in HIV-infected persons. HIV contributes to TB because immune
suppression increases the likelihood of rapid progression from TB infection to TB
disease. In Illinois, the percentage of TB cases diagnosed in foreign-born individuals is
increasing. CDC recommends that all immigrants, refugees, foreign-born students and
their families, and others accompanying them into the country be tuberculin-test
screened and medically treated when appropriate.
Both suspected and confirmed cases of TB are reportable in Illinois. The sooner
cases are reported to the local TB control authority, the sooner their personnel can
begin investigations which may interrupt transmission of TB in the community.
Extensively drug resistant (XDR) TB is TB which is resistant to isoniazid and rifampin
and resistance to any fluoroquinolone, and resistance to at least one second-line
injectable drug (amikacin, capromycin or kanamycin). From 1993 to 2006, 49 TB cases
in the United States were classified as XDR-TB including one case from Illinois.
The recommended length of drug therapy for most types of TB is six to nine
months. Treatment of multi-drug resistant TB requires administration of four to six drugs
for 18 to 24 months. Patients with both TB and HIV are more likely to die during anti-TB
treatment than patients not infected with HIV.
During 2007, a total of 13, 299 cases (4.4 per 100,000) were reported to CDC.
196
Case definition
A confirmed case of tuberculosis in Illinois is a case that is either
laboratory confirmed or is a case that meets the clinical case definition criteria:
1)
A positive tuberculin skin test
2)
Other signs and symptoms compatible with tuberculosis, such as
an abnormal, unstable chest radiograph, or clinical evidence of
current disease
3)
Treatment with two or more anti-tuberculosis medications
4)
Completed diagnostic evaluation
Laboratory criteria for diagnosis are isolation of M. tuberculosis from a
clinical specimen, demonstration of M. tuberculosis from a clinical specimen by
DNA probe or mycolic acid pattern on high-pressure liquid chromatography, or
demonstration of acid-fast bacilli in a clinical specimen when a culture has not
been or cannot be obtained.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – There were 521 cases reported
(4.1 per 100,000 population). This is the second year that a decrease in
reported TB cases occurred. A decrease of 12.6 percent occurred from 2006
to 2007.
• Age - The highest incidence of TB occurred in older age groups (Table 17).
• Gender – Sixty-three percent were male.
• Race/ethnicity - Thirty-four percent were African American (non-Hispanic), 15
percent white (non-Hispanic), 25 percent Hispanic and 25 percent were Asian
or Pacific Islander.
► The number and percent of foreign-born TB cases increased in 2007
(N = 304, or 59 percent) as compared to 2006 (N = 305, or 45
percent) (Figures 97 and 98). Cases were born in 43 different
countries. The largest number of cases were born in Mexico (93, 31
percent), followed by India (54, 18 percent) and the Philippines (46,
15 percent).
• Risk factors - Homeless in past 12 months (6.5 percent), being an inmate in a
correctional facility (3 percent), residing in a long-term care facility (1.5
percent) and injection drug use (0.5 percent).
• Drug resistance – Four cases were multi-drug resistant. No cases were
extensively drug resistant.
• Diagnosis – Seventy-eight percent were culture confirmed, 1 percent were
smear positive, 8 percent met a clinical case definition and 13 percent were
provider diagnosed.
• Clinical syndrome – Sixty-eight percent of cases were pulmonary only, and 26
percent were extrapulmonary.
• Underlying conditions – Ten percent of 521 cases were HIV positive.
Summary
In 2007, 521 cases of TB were reported in Illinois with an incidence rate of
197
4.1 per 100,000, which is very similar to the national incidence rate. Fifty-nine
percent of these cases were among persons born outside of the United States.
An increasing percentage of foreign-born cases are being seen in Illinois, with
India, Mexico and the Philippines being the most common countries of origin.
Public health attention must continue to focus on high-risk groups, especially
those born outside of this country. Illinois is one of seven states reporting more
than 500 cases and is fifth in the nation in the number of cases reported.
Table 17. Age Distribution of Tuberculosis Cases in Illinois, 2007
Age
Incidence *
< 5 years
1.1
5 – 14
0.4
15 – 24
2.4
25-44
4.4
45-64
5.9
65+
8.0
All
4.1
U.S.
4.4
* Incidence per 100,000 based on 2000 population.
Source: Illinois Department of Public Health
Number of cases
Figure 97. Tuberculosis Cases in Illinois, 2002-2007
500
400
300
200
100
0
415
265
407
273
339
328
268
230
305
264
304
217
Foreign born
US born
2002
2003
2004
2005
Year
198
2006
2007
Figure 98 . Country of Origin for Foreign-born TB Cases, Illinois, 2007
18%
India
Mexico
China
Philippines
Rep. of Korea
Other
29%
3%
15%
199
30%
5%
Tularemia
Background
Tularemia is caused by Francisella tularensis and is a zoonotic disease
that infects vertebrates especially rabbits and rodents. Tularemia can be
classified into six primary syndromes: ulceroglandular (the most common form),
glandular, typhoidal, oculoglandular, oropharyngeal, and pneumonic. The case
fatality rate can be 30 percent to 60 percent if untreated and typhoidal. Tularemia
can be divided into four subspecies. Human disease is mainly associated with F.
tularensis subsp tularensis, found only in North America, and the moderately
virulent F. tularensis subsp. Holartica, which is endemic throughout the northern
hemisphere. F. tularensis subspecies tularensis can be separated into two
subpopulations in the United States, A.I. and A.II. A.1. occurs primarily in the
central United States and A.II. occurs primarily in the western United States.
Tularemia can affect many wildlife species, including prairie dogs,
squirrels and cats in addition to humans. Both ticks and biting flies can serve as
vectors in the United States.
The most common modes of transmission are tick bites and handling
infected animals. The disease also can spread through ingestion of contaminated
water or food, inhalation, and insect bites.
Tularemia has two peaks in occurrence; a peak in the summer reflects
transmission from ticks and a peak in winter reflects transmission from animal
contacts, especially rabbits, often during hunting or trapping seasons. The most
important epizootic hosts for tularemia in the United States include rodents and
lagomorphs. Tularemia has been associated with die-offs in exotic animals, such
as prairie dogs.
The most common tick vectors in the United States are the American dog
tick (Dermacentor variabilis), the Lone Star tick (Amblyomma americanum) and
the Rocky Mountain wood tick (D. andersoni).
The incubation period is three to five days. It can take 10 to 20 days for
seroconversion. Clinical signs in people include fever, chills, malaise, cough,
myalgias, vomiting and fatigue followed by the development of one of six clinical
syndromes. Isolation of F. tularensis requires biosafety level 3 facilities.
Tularemia is considered a possible bioterrorism agent. Vaccination is
recommended only for limited numbers of persons in high-risk occupations.
In a study of tularemia in Missouri from 2000 to 2007, 72 percent of the
190 cases were associated with a tick bite prior to illness onset. The
ulceroglandular form was the most common manifestation. Eight percent of tick
bite exposures occurred from May to September. Approximately 40 percent of all
tularemia cases each year in the United States occur in Arkansas, Oklahoma and
Missouri.
In 2007, 137 cases were reported to CDC from 28 states.
Prevention methods include wearing gloves when handling dead animals,
especially rabbits and rodents; avoiding bites of ticks, flies and mosquitoes by
using insect repellents, cooking game meat thoroughly, and avoiding drinking of
untreated water.
200
Case definition
The CDC case definition for a confirmed case of tularemia is a clinically
compatible case with either isolation of F. tularensis from a clinical specimen or a
four-fold or greater rise in serum antibody titer to F. tularensis antigen. A
probable case is a clinically compatible case with either detection of F. tularensis
in a clinical specimen by fluorescent antibody or an elevated serum antibody titer
to F. tularensis antigen in a patient with no history of vaccination.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – One case was reported. This
case was confirmed. The median number of cases per year for the last five
years is one case.
• Age - The case’s age was 47.
• Gender – This case was female.
• Seasonal variation – Onset of illness was in May.
• Geographic distribution – The exposure site for the case was Missouri.
• Symptoms/diagnosis/treatment – She had fever, lymph node enlargement,
vomiting and a skin ulcer from which the organism was cultured. The case
was hospitalized. The organism was cultured from the site of the tick bite.
• Past incidence - The numbers of cases in Illinois by year are as follows:
1991 (five), 1992 (two), 1993 (three), 1994 (three), 1995 (four), 1996 (four),
1997 (five), 1998 (five), 1999 (two), 2000 (four), 2001 (14), 2002 (five), 2003
(one), 2004 (five), 2005 (one) and 2006 (one).
Summary
One case of tularemia was reported in 2007. The case probably acquired
infection through a tick bite in Missouri.
Suggested readings
Turabelidze, G. et. al. Tularemia – Missouri, 2000-2007. MMWR 2009;
58(27): 744-48.
201
Typhoid Fever
Background
Typhoid fever is a systemic infection caused by infection with Salmonella
enterica serotype Typhi. The incubation period is from three days to three
months with a usual range of one to three weeks. Transmission of typhoid fever
is usually by ingestion of food or water contaminated by fecal or urinary carriers
of S. enterica serotype Typhi. Types of products implicated in some countries
include shellfish, raw fruits, vegetables and contaminated milk or milk products.
Unlike other types of Salmonella, S. enterica ser. Typhi is not found in animal
reservoirs; humans are the only reservoirs. In developed countries like the United
States, most cases are sporadic after travel to endemic areas. The infectious
dose ranges from 1,000 to 1 million organisms. Constipation is more common
than diarrhea in adults. The onset of bacteremia with typhoid fever results in
fever, headache, abdominal discomfort, dry cough and myalgia. Other findings
may include bradycardia, rash and splenomegaly. Complications may include
gastrointestinal bleeding, intestinal perforation and typhoid encephalopathy.
Relapse may occur in 5 percent to 10 percent of patients, usually two to three
weeks after resolution of fever. As many as 10 percent of untreated patients will
shed organisms in the feces for up to three months. One percent to four percent
may develop long-term carriage of the organism for as long as one year. Most
carriers are asymptomatic. Chronic carriage is more common in women, the
elderly and in patients with cholelithiasis.
Typhoid fever is typically diagnosed with blood cultures. Bone marrow
cultures also can be used. For travelers to developing countries, water should be
boiled or bottled and food should be thoroughly cooked to avoid acquiring typhoid
fever. Vaccination is recommended for persons traveling to areas where typhoid
is endemic.
In 2007, 434 typhoid fever cases were reported in the United States.
Approximately three fourths of all cases occur among persons who report
international travel during the prior month.
Case definition
A confirmed case is a clinically compatible illness with isolation of S.
enterica ser. Typhi from blood, stool or other clinical specimen. A probable case
is defined as a clinically compatible illness that is epidemiologically linked to a
confirmed case in an outbreak.
Descriptive epidemiology
• Number of cases reported in Illinois in 2007 – 24 (five-year median = 18)
(see Figure 99). All were confirmed cases.
• Sex – Thirteen (54 percent) were male.
• Age - Cases ranged in age from four to 61 years of age (median = 26
years).
• Race/ethnicity – Thirteen of 21 (62 percent) were Asian; one (5 percent)
was white, two (9 percent) were African American and five (24 percent)
202
were other races. Two of 17 reporting ethnicity (12 percent) were
Hispanic.
• Seasonal variation – Cases were reported from January through
December with no seasonal increase.
• Geographic distribution – Fifty percent of the cases were Cook County
residents and 29 percent were Dupage residents.
• Reporting – Fifty-eight percent were reported by laboratories and 42
percent were reported by infection control professionals.
• Diagnosis – The specimen testing positive was blood (16), stool and blood
(two), stool (four) and unknown (two). Ten different PFGE patterns were
reported in isolates from the 11 persons tested by PFGE. Two isolates
were Xba1 pattern StyO7X4 and one was StyO6X3. The two with the
same pattern were not from the same household but both had been in
Pakistan.
• Employment - No cases were reported to be in sensitive occupations.
• Treatment/outcomes - Eighteen of 23 cases (78 percent) were
hospitalized. No deaths were reported.
• Risk factors - Travel destinations for imported cases included India (10),
Pakistan (four), Mexico (two), Bangladesh (one), Thailand (one) and
Indonesia (one). Three persons reported no travel and no source of infection
could be identified. One person had an unknown travel history and one had
travel to an unknown location. Two Dupage County residents had not traveled
outside the country but isolates were not PFGE’d. In 1999 a cluster of nontravel associated typhoid fever cases occurred in the same city of Glen Ellyn.
Summary
There were 24 typhoid fever cases reported in Illinois in 2007. Illinois had
the third highest number of cases in the United States. Most cases were acquired
outside the United States. India and Pakistan were the most common travel
destinations for those cases who reported travel outside the United States.
Number of cases
Figure 99. Typhoid Fever Cases in Illinois, 2002-2007
30
25
20
15
10
5
0
24
23
17
2002
18
2003
18
16
2004
2005
Year
203
2006
2007
Varicella (chickenpox)
Background
Chickenpox (varicella), a highly infectious disease caused by varicellazoster virus (VZV), is characterized by sudden onset of slight fever and a rash.
Lesions present with successive crops and several stages of maturity present at
the same time. Serious complications of varicella may occur and can include
pneumonia, secondary bacterial infections, hemorrhagic complications and
encephalitis. Herpes zoster (HZ) or shingles is a local manifestation of
reactivation of latent varicella in dorsal root ganglia. Severe pain and paresthesia
may accompany this manifestation. Fifteen percent to 30 percent of the
population experience HZ during their lifetime. Postherpetic neuralgia can occur
with debilitating pain weeks to months after resolution of HZ. Risk factors for HZ
include initial infection with varicella in utero or when younger than 18 months of
age. Intrauterine VZV infection can result in congenital varicella syndrome,
neonatal varicella or HZ during infancy or early childhood.
The incubation period is 14 to 16 days after exposure to rash (range 10 to
21 days). A person is communicable for one to two days before rash onset and
remains infectious until the rash is crusted over (usually four to seven days after
rash onset). The disease is transmitted through direct contact between persons,
droplet or airborne spread of vesicle fluid or respiratory tract secretions or
indirectly through fomites. Secondary attack rates in households can be 90
percent.
Varicella related deaths became nationally notifiable in 1999 to allow for
evaluation of the vaccine program. In the United States, six varicella deaths were
reported to CDC in 2007. There were 40,146 individual varicella cases reported.
Two live attenuated vaccines are available for varicella zoster virus in the
United States. One was licensed in 1995 and the other in 2005.
Recommendations for varicella preventive are to:
1)
Implement two-dose varicella vaccination program for children (the
first dose at 12-15 months and the second at 4 to 6 years)
2)
Provide a second catch-up varicella vaccination for children
adolescents and adults who had previously received one
dose’
3)
Encourage routine vaccination of all healthy persons aged greater
than 13 years without evidence of immunity
4)
Conduct prenatal assessment and postpartum vaccination
5)
Expand use of varicella vaccination for HIV-infected children with
age-specific CD4 and T lymphocyte percentages of 15
percent to 24 percent and adolescentsand adults with CD4
and T lymphocyte counts greater than 200 cells/ul
6)
Establish middle school, high school and college entry vaccination
requirements
In 2003, IDPH required reporting of adult chickenpox (in those over 20
years of age) within 24 hours under the Medical Studies Practice Act. The
204
Department requests voluntary reporting of varicella deaths. Permanent rules
and regulations were passed in March 2008. This reporting was implemented
because a case of smallpox in an adult might be misidentified as a case of
chickenpox.
Case definition
The clinical case definition is an illness with acute onset of generazlied maculapapulovesicular rash without other apparent cause. The laboratory criteria for
diagnosis is: isolation of varicella virus from a clinical specimen, OR DFA
positive, or PCR positive or significant rise in varicella IgG antibody.
A confirmed case is one that is laboratory confirmed or that meets the clinical
case definition and is epidemiologically linked to another probable or confirmed
case.
A probable case is a case that meets the clinical case definition, is not laboratory
confirmed and is not epidemiologically linked to another probable or confirmed
case.
Descriptive epidemiology
• Number of cases – The total number of cases reported was 1,091. In adults
(21 years of age or older) 105 cases were reported. Fifty-six of the adult
cases were confirmed; the rest were probable. The summary below only
includes adult varicella cases.
• Sex – Forty-eight percent of cases were female.
• Age – Cases ranged in age from 21 to 87 years of age (mean = 34).
• Race/ethnicity – Cases were African American (24 percent), white (47
percent), Asian (22 percent) and other (6 percent). Twenty-five percent were
Hispanic.
• Geographic distribution – Cases were reported from 21 counties.
• Outcomes – Seventeen percent of adult chickenpox cases were hospitalized.
• Fatalities – No varicella deaths were reported in adults in 2007.
• Reporters – The most common reporter was infection control professionals
(41 percent),
Summary
Varicella (chickenpox) is reportable in aggregate in Illinois, and over 1,000
cases were reported in 2007. The number of reported chickenpox cases has
been declining since 1997. There were 105 adult cases. No fatal adult cases
were reported in 2007. The goal for vaccination levels is 90 percent by 2010.
205
Vibrio Non-cholera
Background
Vibrio parahaemolyticus infection causes acute diarrhea, vomiting and
fever for 1 to 3 days. The incubation period usually occurs within 24 hours after
eating contaminated food. Foods most often associated with this illness include
raw or undercooked shellfish or other cooked foods that have been cross
contaminated with raw shellfish. Vibrio spp multiply rapidly and can increase
quickly if sea food is not rapidly refrigerated after harvest and kept at proper
temperatures. Diagnosis is by culturing stool specimens in persons with shellfish
consumption history and symptoms. The selective media, thiosulfate-citrate-bile
salts-sucrose (TCBS), can be used to isolate the organism. It is estimated that 20
cases actually occur for every laboratory confirmed case reported to CDC.
In CDC FoodNet data the incidence was 0.2 per 100,000 (range at
FoodNet sites: 0.0 to 0.46). The incidence did not change between 2004-2006
and 2007. The Vibrio species identified were V. parahaemolyticus (56 percent),
V. alginolyticus (16 percent) and V. vulnificus (12 percent).
In January 2007, vibriosis became a nationally notifiable disease.
Nationally 549 cases were reported in 2007.
Shellfish should be thoroughly cooked to kill pathogens, like V.
parahaemolyticus.
Case definition
A confirmed case is a clinically compatible case from which Vibrio spp.
has been isolated from a clinical specimen. A probable case is a clinically
compatible case that is epidemiologically linked to a confirmed case; or a
clinically compatible case who consumed epidemiologically incriminated food
(usually seafood) from which 1 million or more organisms per gram have been
identified.
Descriptive epidemiology - V. parahaemolyticus
• Cases – Four cases were reported in 2007. All were confirmed.
• Seasonal – Cases were reported from May to November.
• Race – One case was white, one was Asian, one reported being an
“other” race and one did not report race; one person reported being
Hispanic.
• Sex – Seventy-five percent were male.
• Age – Cases ranged from one to 61 years of age (mean = 34).
• Geographic location – Three cases resided in Cook County and one in
Dupage County.
• Risk factors – Two cases reported eating raw oysters, one had no known
risk factor and one could not be interviewed.
• Outcome – One case was hospitalized. No cases were reported to be
fatal.
• Reporter – One was reported by a laboratory, two were reported by
hospitals and one had an unknown reporter.
206
Descriptive epidemiology - other Vibrio species
• Cases - Four cases were reported in 2007. All were confirmed.
• Seasonal – Cases were reported from July to September.
• Race – Three of three cases with race listed were white; two were
Hispanic.
• Sex – Fifty percent of the cases were male.
• Outcome – All three cases with a hospitalization history were
hospitalized. One case of V. cholerae non-01 was fatal.
• Reporter – One case was reported by a laboratory, two by hospitals
and one by a university health care center.
• Age – Cases ranged in age from 7 years to 55 years of age (mean =
31).
• Geographic – Three counties reported cases including Cook (two
cases), McHenry (one) and Vermilion (one).
• Species – Vibrio species identified in cases included Vibrio
alginolyticus (one), Vibrio cholerae non 01 (one), Vibrio vulnificus (one)
and Vibrio hollisae (one).
• Site of isolation – All but the V. alginolyticus case had isolates from
stool. The V. alginolyticus isolate was from a wound.
• Risk factors – The V. vulnificus case reported seafood consumption.
The V. alginolyticus had cellulites after cutting herself on an oyster in
South Carolina waters. No history could be obtained from the V.
cholerae non-01 or the V. hollisae case.
Summary
A total of eight Vibrio cases were reported in Illinois in 2007. This was the
first year Vibrio became a nationally notifiable disease.
Suggested readings
Centers for Disease Control and Prevention. FoodNet 2007 Surveillance
Report. Atlanta: U.S. Department of Health and Human Services, 2009.
207
Yersiniosis
Background
Yersiniosis, an infrequently reported cause of diarrhea in the United
States, is caused by Yersinia enterocolitica or Y. pseudotuberculosis.
Transmission is by the fecal-oral route, through consumption of contaminated
food or water or by contact with infected people or animals. The incubation
period is three to seven days. Fecal shedding occurs for as long as symptoms
are present, usually two to three weeks. Manifestations of the disease include an
acute febrile diarrhea and abdominal pain. Symptoms can mimic appendicitis.
Bloody diarrhea is seen in 10 percent to 30 percent of children with Y.
enterocolitica. Animals are the principal reservoir for Yersinia, with the pig the
primary reservoir of Y. enterocolitica and rodents as the main reservoirs for Y.
pseudotuberculosis. Most pathogenic strains of Y. enterocolitica have been
isolated from raw pork or pork products. Chitterling consumption or contact with
someone preparing chitterlings is a common exposure history for those with
yersiniosis. Yersinia is cold-tolerant and can replicate under refrigeration.
Of the 10 diseases (those caused by Campylobacter, Cryptosporidium,
Cyclospora, E. coli O157:H7, HUS, Listeria monocytogenes, Salmonella,
Shigella, Vibrio and Yersinia enterocolitica) under active surveillance in the
federal FoodNet sites, Yersinia comprised 0.98 percent of the reported infections
in data from 2007. The incidence rate per 100,000 for yersiniosis in 2007 data
was 0.36 (range from 0.15 to 0.51) at the 10 FoodNet sites. The incidence of
Yersinia infections did not change between 2004-2006 and 2007.
Case definition
The case definition in Illinois includes only a positive culture for Yersinia.
A probable case is an case epidemiologically linked to a confirmed case.
Descriptive epidemiology
• Number of reported cases in Illinois in 2007 - 24 (five-year median = 25) (see
Figure 100). The incidence rate per 100,000 was 0.19. All were confirmed.
• Age – Six cases (25 percent) occurred in those younger than 1 year of age.
(Figure 101).
• Gender – Sixty-seven percent of cases were female.
• Race/ethnicity – Forty-three percent were African American and 48 percent
were white. None were Hispanic.
• Seasonality – Figure 102 shows the case onsets by month.
• Geographic location – Forty-four percent of cases were residents of Cook
County.
• Clinical history – Seventeen of 20 (85 percent) had diarrhea; six of 20 (30
percent) had vomiting, and nine of 20 (47 percent) had fever.
• Outcome – For 22 cases with complete case information, 10 cases were
hospitalized and no cases were reported to be fatal.
• Risk factors – History of chitterling consumption was obtained for 14 cases,
and two had exposure to chitterlings. Both cases with chitterling consumption
208
•
were less than one years of age.
Reporting – The most important source of reporting was laboratories (13
cases) followed by infection control professionals (10 cases).
Summary
The yersiniosis incidence rate of 0.14 per 100,000 for 2007 in Illinois was
lower than that found in the CDC’s FoodNet sites. One-quarter of Illinois cases in
2007 occurred in children younger than a year old.
Suggested readings
Centers for Disease Control and Prevention. FoodNet 2007 Surveillance
Report. Atlanta: U.S. Department of Health and Human Services, 2009.
Vugia, D., et. al. Preliminary FoodNet data on the incidence of infection
with pathogens transmitted commonly through food-10 states, 2007. MMWR
2008; 57(140: 366-69.
Number of cases
Figure 100. Yersiniosis Cases in Illinois, 2002-2007
40
30
25
31
28
25
24
22
20
10
0
2002
2003
2004
2005
2006
2007
Year
Number of cases
Figure 101. Age Distribution of Yersiniosis Cases in Illinois, 2007
8
6
4
2
0
<1 y r
1-4 yr
5-9 yr
10- 19 y r
20-2 9 yr
Age Group
209
30-39 yr
40-49 yr
5 0-59 yr
>59 yr
Number of cases
Figure 102. Yersinia Cases in Illinois by Month, 2007
6
4
2
0
Jan
Feb
Mar
Apr
May
Jun
Year
210
Jul
Aug
Sep
Oct
Nov
Dec
Non-foodborne, Non-waterborne Outbreaks, 2007
Case definition
A non-foodborne, non-waterborne (NFNW) outbreak is an incident in
which two or more persons (usually residing in separate households) experience
the onset of a similar, acute illness following a common exposure (other than
ingestion of common food or drink or exposure to recreational water).
For NFNW outbreaks, the number ill reflects those who meet a clinical
case definition. For outbreaks where the etiologic agent was suspected and not
confirmed, and the clinical syndrome matched the suspect etiologic agent but no
laboratory confirmation was obtained, the suspect cause is ascribed to this
etiologic agent.
The Department receives reports of potential NFNW outbreaks from many
sources. Outbreak investigations, which are conducted by local health
departments, may not result in an Illinois NFNW outbreak designation and will
not be counted in the state totals.
Descriptive epidemiology
• Number of outbreaks – There were 103 NFNW outbreaks reported and
counted as an outbreak in 2007. The number of outbreaks by month is
shown in Figure 103.
• Pathogens – Pathogens causing these outbreaks included bacterial
causes (26 outbreaks), viral (65 outbreaks), fungal (two outbreaks) and
unknown (10 outbreaks) (Tables 18 and 19). The viral outbreaks included
norovirus (63) and enteroviruses (two). The bacterial outbreaks included
Shigella sonnei (10), methicillin resistant S. aureus (MRSA) (seven),
Salmonella (three), group A Streptococcus (one), S. aureus (one), C.
difficile (one), Campylobacter (one), Q fever (one) and Serratia
marcescens (one). The two fungal outbreaks were due to histoplasmosis.
A listing of individual outbreaks is provided in Table 20.
Figure 103. Number of Non-foodborne Non-waterborne
Outbreaks by Month of First Onset, Illinois, 2007
30
Number of 20
outbreaks
reported 10
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
211
Table 18. Non-foodborne Non-waterborne Outbreaks, Cases, and Deaths by Etiology in Illinois, 2007
Outbreaks
Cases
#
Etiology
Count
%
Count
%
Bacterial
S. marcescens
1
22
C. difficile
1
6
S. aureus, sensitive
1
6
MRSA
7
29
Campylobacter
1
3
Salmonella
3
64
Shigella
10
61
Streptococcus, Group A
1
2
Q fever
1
4
Total Bacterial*
26
197
Viral
Norovirus
Enterovirus
Total Viral
Fungi
63
2
65
97
3
2519
12
2531
99
1
Deaths
Count
0
0
0
0
0
0
0
1
0
1
0
0
0
Histoplasmosis
2
5
0
Total Fungal
2
5
0
10
394
0
UNKNOWN
Table 19. Non-foodborne Non-waterborne Outbreak Pathogens by Testing Status in Illinois, 2007
Confirmed
Suspected
Etiology
Count
%
Count
%
Bacterial
S. marcescens
1
0
C. difficile
1
0
S. aureus
1
0
MRSA
7
0
Campylobacter
1
0
Salmonella
3
0
Shigella
Invasive Streptococcus,
Group A
10
0
1
0
Q fever
1
0
Norovirus
36
27
Enterovirus
1
1
Total Viral
37
28
Histoplasmosis
2
0
Total Fungal
2
0
Unknown
Count
Total Bacterial
Viral
Fungi
Unknown
10
212
%
--
%
Specific Types of NFNW Outbreaks
BACTERIAL OUTBREAKS
There were 26 bacterial NFNW outbreaks reported in 2007. These included the
following pathogens: Shigella (10), MRSA (seven), Salmonella (three), invasive
Group A Streptococcus (one), Campylobacter (one), C. difficile (one), Q fever
(one), Serratia (one) and S. aureus non methicillin resistant (one).
Campylobacter
Background
Non-foodborne non-waterborne Campylobacter outbreaks can be caused
by contact with animals or animal feces.
Descriptive epidemiology
There was one NFNW outbreak of Campylobacter reported in 2007.
Individual description
• Three cases of Campylobacter occurred in persons who reported handling
poultry at a friend’s house in Winnebago County.
C. difficile
Background
C. difficile is a spore forming bacteria. This organism can produce two
toxins (A and B). The organism can cause diarrhea and pseudomembranous
colitis. Many cases have been on antimicrobials prior to onset of illness.
Asymptomatic carriers are possible. The symptoms can recur after treatment.
The mortality ranges from 1 percent to 2.5 percent. The incidence and severity
has been increasing in the United States. Community-associated C. difficile also
is being observed. Approximately one-third of cases had no prior antimicrobial
use.
Descriptive epidemiology
Number of outbreaks – One outbreak of C. difficile was reported in Illinois in
2007.
Individual description
• A cluster of six cases of C. difficile occurred in a long-term care facility
associated with a hospital in McHenry County.
MRSA
Background
Methicillin resistant S. aureus (MRSA) can cause skin and soft tissue
infections. These infections can cluster in various situations including sports
213
teams, prisons and other locations where crowding and close contact between
persons occurs.
Case definition
Two or more laboratory confirmed MRSA cases with a common non
health-care associated epidemiologic link would be needed to be considered a
confirmed outbreak.
Descriptive epidemiology
The seven MRSA outbreaks took place in Dupage, Randolph, St Clair,
Coles, Cook, Madison and LaSalle Counties. Outbreaks took place in a hospital
(two), work site (one), university (one), developmentally delayed facility (one),
assisted living (one) and school (one). Twenty-nine individuals with MRSA were
involved in the seven outbreaks. The outbreaks took place in April (one), May
(one), June (one), July (one), August (two) and November (one).
Individual Outbreak Descriptions
 A cluster of three cases of MRSA infection occurred in a high school in
Dupage County in April. Skin lesions occurred in one student, one teacher
and a boyfriend of another teacher.
 A cluster of three cases of MRSA skin infections occurred in three residents
at a mental health hospital in Randolph County in May. An additional three
persons were identified as nasally colonized with MRSA.
 A cluster of two cases of MRSA occurred at a work site in St Clair County.
One onset was in January and another in June. Both were soft tissue skin
infections and neither case required hospitalization.
 A cluster of six cases of MRSA occurred in a university in Coles County in
August.
 A cluster of four skin and soft tissue infections due to MRSA were identified in
a facility for the developmentally disabled in Cook County in July.
 A cluster of eight confirmed MRSA skin and soft tissue infections occurred in
an assisted living facility in Madison County in August.
 A cluster of three MRSA cases occurred in neonates born at a hospital in
LaSalle County in November. Onsets occurred at 14 to 21 days of age.
Q fever
Background
Q fever, caused by Coxiella burnetti can cluster in persons in contact with
infected animals, especially sheep and goats.
Case definition
A cluster of two or more cases of Q fever identified with a common
epidemiologic link.
Descriptive epidemiology
Number of outbreaks reported – One outbreak of Q fever was reported in Illinois
214
in 2007.
Individual Outbreak Description
• Four cases of Q fever (1 confirmed, 3 probable) occurred in workers at a
slaughter plant in Carroll County from May to June 2007. Symptoms
included fever, retrobulbar headache, myalgia and cough. On person had
a four-fold rise in titer on acute and convalescent serum samples and
three persons had a single serum sample positive. One person was
hospitalized. At this facility pregnant goats were slaughtered.
Salmonella
Background
Non foodborne, non waterborne Salmonella outbreaks can occur due to
contact with animals or from person to person exposure.
Case definition
A NFNW outbreak is defined as multiple cases of the same Salmonella
serotype with a common epidemiologic link that is not transmitted by foodborne
or waterborne means.
Descriptive epidemiology
Number of outbreaks reported – There were three NFNW Salmonella outbreaks
reported in Illinois in 2007. Sixty-four persons were affected in the three
outbreaks. Two of the outbreaks were associated with animal contact. In one
outbreak the source was turtle contact and in the other poultry contact was
suspected as the cause of infection. In the third outbreak a source could not be
identified. Two outbreaks were multi-state and one was in Madison County
residents.
Individual Descriptions
• A multi-state outbreak of Salmonella infection occurred in persons with
turtle contact in 2007. Both paratyphi B and I 4,5,12:b:- serotypes were
involved. Five Illinois residents matched the national pattern and reported
turtle exposure. Cases occurred from June through September and both
Lake and Cook County residents were affected.
• Two cases of Salmonella ser. Montevideo from separate households in
Madison County with onsets in May reported exposure to poultry. Both
PFGE matched a multi-state outbreak linked to baby chick exposure. The
PFGE pattern was J1XX01.0049. Both cases reported purchasing baby
chicks from the same local chain feed store. One case had direct contact
with the baby poultry and the second case had another household
member who had contact with the baby poultry. A letter was sent to the
feed store headquarters reminding them that it is not legal to sell baby
poultry in Illinois as pets.
• A cluster of 57 S. ser. Muenchen cases with matching PFGE patterns
occurred in Illinois in 2007. Onsets of cases ranged from April 5 through
215
June 13. Cases were residents of 14 counties. Twenty-six were female
and 30 were male, one did not have sex listed. The PFGE pattern was
CDC JJ6X01.0641 or Illinois Smu07X8. It was not possible to identify a
source of infection for these cases.
Serratia marcescens
Background
S. marcescens is the species of Serratia most commonly seen in human
infections. This organism is common in the environment. S. marcescens can
cause a wide variety of nosocomial infections. The most common site of infection
is the urinary tract but it is also frequently isolated from wounds and the
respiratory tract.
Case definition
A confirmed outbreak would be a report of multiple cases of S.
marcescens in a single facility within a short period of time.
Descriptive epidemiology
Number of outbreaks reported - A single outbreak of S. marcescens was
reported in Illinois in 2007.
Individual outbreak description
• Twenty-two cases of Serratia marcescens from exposure to contaminated
prefilled syringes were reported in Chicago. This was a multi-state
outbreak.
Shigella
Background
The Shigella organism can cause person-to-person outbreaks. Symptoms
include fever and diarrhea.
Case definition
The case definition for an outbreak of Shigella is identification of the same
serotype of the bacteria in two or more ill persons with a common epidemiologic
link.
Descriptive epidemiology
The counties where outbreaks took place included Rock Island (five),
Champaign (three) and Winnebago (two). Sixty-one persons became ill with
Shigella as part of the 10 outbreaks. The settings for the 10 outbreaks included
day care (four), school (two), and one each for day camp, developmentally
delayed facility, shelter and a head start program at a school. The outbreaks took
place in January (one), March (two), April (one), June (one), July (one), August
(one) and September (three).
Individual Descriptions
• A cluster of seven Shigella sonnei cases occurred in a school Head start
216
•
•
•
•
•
•
•
•
•
program in Winnebago County in January. Six were laboratory confirmed.
No hospitalizations resulted from the cluster.
A Shigella outbreak was reported in a facility for the developmentally
disabled in Winnebago in March. Ten residents, three staff and one family
member of a resident became ill with S. sonnei. No ill persons were
hospitalized.
In March a cluster of two cases of Shigella sonnei were identified in a day
care center in Champaign County. Neither case required hospitalization.
A cluster of S. sonnei occurred in a shelter in Champaign County in April.
Two were adults and two were children. Onsets of illnesses occurred from
April 1 to April 20.
A cluster of three Shigella sonnei cases were associated with a day camp
in Champaign County in June. Two cases attended the camp and one was
a household member of someone who attended the camp. No cases
required hospitalization. Seventy five persons attended the camp.
Six cases of S. sonnei occurred between July 11 and July 28 in attendees
of a day care in Rock Island.
A cluster of six cases of S. sonnei occurred in an elementary school in
Rock Island between August 24 and September 28. One case was an
adult and five were in school children. Ages of children ranged from two to
12 years.
A cluster of four S. sonnei cases occurred in a Rock Island elementary
school between September 15 and September 23. Three were children
between the ages of 5 and 9 years and one was an adult.
A cluster of eight cases of S. sonnei occurred in a day care in Rock Island.
Illness onset dates ranged from September 17 to November 15. Seven
were children and one was an adult.
A cluster of seven cases of S. sonnei occurred in a day care in Rock
Island. Illness onset dates ranged from September 30 through October 18.
One was an adult and the rest were children between two and three years
of age.
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
January
March
April
June
July
August
September
Counties of outbreaks
217
Confirmed
10
61
1
0
1
2
1
1
1
1
3
Champaign
Rock Island
Winnebago
3
5
2
Staphylococcus aureus, not resistant
Background
Sensitive isolates of non-invasive S. aureus can cause clusters of infection in
neonatal units.
Case Definition
Multiple isolations of S. aureus in babies in newborn nurseries are reportable in
Illinois.
Descriptive epidemiology
Number of clusters reported – A single cluster of S. aureus in a newborn nursery
was reported in Illinois.
Individual outbreak description
• A cluster of six cases of S. aureus occurred in a hospital newborn
unit in Dupage County. Cases were non-invasive and isolates were
not antimicrobial resistant. Four affected babies were born on
September 5 and two on September 9.
Streptococcus, Group A
Background
Invasive Group A Streptococcus infection involves persons with clinically
compatible illness and cultures confirmed from a sterile site. Clusters of invasive
Group A Streptococcus infection can be identified in group settings, especially
long-term care facilities.
Case definition
For invasive Group A Streptococcus outbreaks, a confirmed outbreak
requires culture confirmation of two or more cases of sterile site group A
Streptococcus in persons with a common epidemiologic link. For an outbreak of
non-invasive Group A Streptococcus at least 10 persons with a common
epidemiologic link must be clinically compatible and five test positive for Group A
Streptococcus.
Descriptive Epidemiology
Number of outbreaks – There was one outbreak of invasive group A
Streptococcus affecting two persons reported in Illinois in 2007.
Individual outbreak description
• Two invasive group A streptococcus cases occurred in a long-term care
unit. Both persons were hospitalized. One case was fatal. Onsets of
218
illness were May 11 and May 16.
VIRAL OUTBREAKS
There were 65 NFNW viral outbreaks reported. The majority were suspect
or confirmed norovirus outbreaks (N = 63). Two outbreaks were caused by
enteroviruses.
Norovirus outbreaks
Background
Noroviruses are the most common cause of sporadic cases of acute
gastroenteritis. Noroviruses have a low infectious dose, environmental
persistence and prolonged shedding. In long-term care facilities, incontinent
residents can predispose a facility to outbreaks of norovirus. Norovirus outbreaks
often occur in settings where cluster of vulnerable susceptible people live in close
quarters (long term care, hospitals or day cares) or where turnover of susceptible
people is high (hotels, cruise ships). A study showed that hygiene measures
decreased virus reproduction number for norovirus but the chain of transmission
could not be reduced to below one.
In an outbreak of norovirus in a long-term residential facility in Oregon,
facility employees who cleaned up vomitus were at higher risk for illness.
Descriptive epidemiology
Number of outbreaks – Sixty-three person-to-person norovirus outbreaks were
reported in 2007. Thirty-six outbreaks were confirmed and 27 were suspect. Of
the 36 confirmed outbreaks, 30 were the G2 type, two were G1 and four had an
unknown type. Of the 27 suspect outbreaks, eight were G2 and 19 were
unknown types. The sites of the confirmed outbreaks were long-term care
facilities (22), hospitals (four), assisted care facilities (three), day care (two) and
one each for school, retirement community, developmentally delayed facility,
drug treatment facility and private home. The confirmed norovirus outbreaks
occurred in the following counties: Cook (nine), Winnebago (four), Madison
(four), Kane (three), Morgan (three), Richland (two), Lake (two), Will (two),
Sangamon (two) and one each in Hamilton, JoDaviess, Fulton, Dupage and
Calhoun. There were 1,457 persons who became ill as a result of the confirmed
norovirus outbreaks and 45 persons were hospitalized. There were 1,062
persons affected by the suspect norovirus outbreaks and 10 were hospitalized.
An increase in norovirus outbreaks occurred in January and February (Figure
104).
Individual descriptions of confirmed outbreaks
• An outbreak of norovirus occurred in an assisted living facility in Cook
County in January. Twenty four persons became ill (20 residents and four
staff members). Five ill persons of seven tested were laboratory confirmed
with norovirus G2. Three persons were hospitalized. This was an assisted
living facility regulated by DHFS.
219
•
•
•
•
•
•
•
•
•
•
•
•
•
An outbreak of norovirus G2 occurred in a Hamilton County long-term care
facility in January. Fifteen residents were ill with vomiting and diarrhea and
five were laboratory confirmed. No staff members were ill. No persons
were hospitalized.
An outbreak of norovirus G2 occurred in Winnebago County in January in
a long-term care facility. Two persons tested positive for norovirus. Thirtyfive persons became ill including 21 staff and 14 residents. No persons
required hospitalization.
An outbreak of norovirus G2 occurred in Cook County in January. Thirty
three persons (11 staff and 22 residents) of a long-term care facility
became ill with vomiting and diarrhea. Two of three persons tested
positive for norovirus.
The Chicago DPH reported a long-term care facility with gastrointestinal
illnesses in residents and staff in January. Twenty residents and three
staff were ill. Three were laboratory confirmed with norovirus G2. None
were hospitalized.
In January, a norovirus outbreak occurred in a hospital-associated longterm care facility in Richland County. Seventeen persons (three staff and
14 residents) were ill and two of five tested positive for norovirus, type not
provided.
A norovirus G2 outbreak occurred in a long-term care facility in Richland in
January 2007. Eighty eight (47 staff and 41 residents) were ill with
vomiting and diarrhea. Two were seen in an emergency department but
no one was admitted. Two of three tested positive for norovirus G2.
In January a norovirus outbreak occurred in Cook County at a long-term
care facility. Twenty persons became ill (1 staff and 19 residents). Three
of three tested were positive for norovirus G2.
The Kane County Health Department reported a cluster of gastrointestinal
illnesses in a hospital in January. Thirteen patients, six staff and one
visitor became ill. Three of five stools tested positive for norovirus G2.
An outbreak of norovirus G2 was reported in a Chicago hospital in
January. Thirty-six persons (28 staff and eight residents) became ill.
There were 37 persons (26 staff and 11 residents) who became ill at a
skilled nursing unit at a hospital in Madison County in February. Four of
six tested were positive for norovirus G2. No hospitalizations occurred.
There were 152 persons who became ill at a long-term care facility with
norovirus in February in Lake County. Eight persons were hospitalized.
Five of five persons tested were positive for norovirus G2.
An outbreak of norovirus G2 occurred in JoDaviess County in February.
This outbreak took place in a long-term care facility associated with a
hospital and involved 14 staff and 41 residents. Two were hospitalized.
Five of five persons tested positive for norovirus G2.
In February, an outbreak of norovirus G2 occurred in a long-term care
facility in Will County. Seventy eight persons (45 staff and 33 residents)
became ill. Three of three stools tested were positive for norovirus. One
person was hospitalized.
220
•
•
•
•
•
•
•
•
•
•
•
•
•
•
In February, 21 persons (14 staff and seven residents) became ill at a
hospital in Sangamon County. Six of 10 persons tested positive for
norovirus G2.
In Madison County, an outbreak of norovirus occurred in a long-term care
facility in February. Sixty-three persons (18 staff and 45 residents)
became ill and four of six tested positive for norovirus G2.
Another outbreak in Madison County in February involved 24 ill persons at
a long-term care facility associated with a hospital. Two of seven persons
tested positive for norovirus G2.
Persons at a long-term care facility in Madison County experienced a
norovirus G2 outbreak in late February. Eighty-nine persons (33 staff and
56 residents) became ill. Three of five persons tested positive for
norovirus G2. No persons were hospitalized.
A norovirus outbreak was reported from a long-term care facility in Morgan
County in February. Three of six persons tested positive for norovirus G2.
The number ill was 49 persons (26 residents and 23 staff). No persons
were hospitalized.
The Kane County Health Department reported a norovirus G2 outbreak in
an assisted living facility in February. Thirty-three persons (24 patients and
nine staff members) were ill. Two of two persons tested were positive for
norovirus G2.
A Fulton County long-term care facility reported a cluster of norovirus G2
in February. Twenty-four persons (six staff and 18 residents) became ill.
Two of five tested positive for norovirus G2.
A Skokie LTC facility reported a norovirus outbreak involving 15 persons
(all ill persons were residents) in February. Two of three persons tested
positive for norovirus G2. Three persons were hospitalized.
The Winnebago County Health Department reported a norovirus outbreak
associated with an elementary school in late February. Ninety-five persons
became ill. Four of eight tested positive for norovirus G1.
A Will County long-term care facility reported a norovirus G2 outbreak in
March. Forty-eight (41 residents and seven employees) experienced
gastrointestinal illness. Eighteen were hospitalized.
A retirement community experienced an outbreak of norovirus G2 in
March in Morgan County. Seventy-six persons (23 staff and 53 residents)
became ill. Three of four persons tested positive for norovirus G2.
A hospital LTC facility in Dupage County reported a cluster of
gastrointestinal illnesses in March. Four residents and no staff became ill.
Four of four persons tested were positive for norovirus at a commercial
laboratory.
Fifty-seven persons (11 staff and 46 residents) became ill with norovirus at
a long-term care facility in Calhoun County in April. Two of five persons
tested positive for norovirus G2. No one required hospitalization.
A day care center in Kane County reported a cluster of norovirus
infections in six staff members and 25 children in May. Two of two persons
tested positive for norovirus G2.
221
•
•
•
•
•
•
•
•
Persons at a facility for the developmentally disabled developed norovirus
G2 infection in May in Cook County. Thirty-four persons became ill. Three
of three persons tested positive for norovirus G2. None required
hospitalization.
A cluster of illnesses occurred in a drug treatment center in Chicago in
August. Three persons became ill with vomiting and diarrhea and two
tested positive for norovirus G1.
Fourteen persons reported illness after a group met at a private home in
August in Winnebago County. Two persons tested positive for norovirus
G2.
A group of children at a daycare in Winnebago County developed diarrhea
and vomiting in August. Two tested positive for norovirus G2. Twentyseven (7 staff and 20 children) were affected. None were hospitalized.
Seventeen (15 staff and two residents) of a hospital experienced
gastrointestinal illness associated with norovirus G2. This outbreak
occurred in Sangamon County in November.
Thirty-six (7 staff and 29 residents) became ill in December in a Morgan
County assisted living facility. Two persons were hospitalized.
A long-term care facility in Cook County had 46 persons ill (four staff and
42 residents) with norovirus in December. Sixteen of 20 tested positive for
norovirus at a commercial laboratory. Thirteen individuals were
hospitalized.
Eighteen persons became ill with norovirus in December at a long-term
care facility in Lake County. The type of norovirus was unknown.
Suggested readings
Hedberg, K., et. al. Recurring norovirus outbreaks in a long-term
residential treatment facility – Oregon, 2007. MMWR 2009; 58(25):694-698.
Heijne, J.C.M., et. al. Enhanced hygiene measures and norovirus
transmission during an outbreak. Emer Inf Dis 2009;15(1):24-30.
Number of cases
Figure 104. Norovirus Outbreaks by Month in Illinois, 2007
25
20
15
10
5
0
Suspect
Confirmed
Jan
Feb
Mar
Apr
May
Jun
Jul
Year
222
Aug
Sep
Oct
Nov
Dec
Norovirus
Confirmed
36
1,457
Suspected
27
1,062
45
10
January
February
March
April
May
June
July
August
September
October
November
December
10
13
3
1
2
0
0
3
0
0
1
3
10
5
4
0
0
0
0
0
0
0
4
4
Bond
Brown
Calhoun
Clinton
Cook
DuPage
Fulton
Hamilton
Jo Daviess
Kane
Lake
Macon
Madison
Massac
McLean
Morgan
Richland
St Clair
Sangamon
Stephenson
Tazewell
Wabash
Will
Winnebago
0
0
1
0
9
1
1
1
1
3
2
0
4
0
0
3
2
0
2
0
0
0
2
4
1
1
0
1
3
3
0
0
1
0
0
1
2
1
2
0
0
2
4
1
1
1
0
2
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
Counties of outbreaks
Enterovirus
Background
Enteroviruses can cause serious disease in neonates. Neonatal systemic
223
enteroviral disease is characterized by multiorgan involvement and can be a fatal
condition. Typical presentations include encephalomyocarditis and hemorrhagehepatitis syndrome. Enterovirus infections are common, especially during the
summer and fall months and typically are spread person-to-person via the fecaloral or oral-oral routes and through respiratory droplets and fomites. Perinatal
transmission can occur around the delivery time.
Case Definition
Multiple cases of enterovirus in a common facility can be considered an
outbreak.
Descriptive epidemiology
Number of outbreaks reported – One confirmed and one suspect outbreak were
reported in 2007. Both occurred in hospitals. Twelve individuals were affected.
Individual Descriptions of Confirmed Outbreaks
• A cluster of Coxsackie B1 infections in neonates were reported in
Chicago, Illinois. One case was fatal and one required a heart transplant.
The cluster was identified in September 2007 after two cases of severe
neonatal disease at a hospital in Chicago.
Suggested readings
Mascola, L., et. al. Increased detections and severe neonatal disease
associated with Coxsackievirus B1 infection-United States, 2007. MMWR 2008;
57(20):553-556.
Fungal Outbreaks
Histoplasmosis
Background
Outbreaks of histoplasmosis have been identified previously in Illinois and
are most commonly associated with occupational exposures, such as bridge
repair or earth moving activities.
Individual descriptions
• One cluster of histoplasmosis occurred in three of six Grundy County
residents. They traveled to southern Illinois for a hunting trip in January
and developed symptoms later that month. All three developed
histoplasmosis. No specific exposure site could be identified that might
have posed a risk.
• Another cluster of at least two probable histoplasmosis cases occurred in
workers at a bridge construction site in Peoria County. One Peoria
resident and one Chicago resident were documented histoplasmosis
cases. Onsets of illness were in September and November.
224
Outbreaks
Total number of ills
Average number of ills/outbreak
Number of cases hospitalized
Number of fatalities
Outbreak months
January
September
Counties of outbreaks
Grundy
Peoria
225
Confirmed
2
5
0
1
1
1
1
Table 20.
Non-foodborne and non-waterborne outbreaks in Illinois in 2007.
Exposure
IDPH Log
Number
Onset
Date
City
County
Ill/
Exposure
Symptoms*
Exposure
source
Agent Implicated
Status
Location of
exposure
IL2007-001
1/1
Melrose Park
Cook
24/24
D,V
Person-person
Norovirus G2
C
Assisted living
IL2007-004
1/2
Rockford
Winnebago
35/U
D,V
Person-person
Norovirus G2
C
LTC
IL2007-002
1/4
Mt. Sterling
Brown
62/104
D,V
Person-person
Norovirus
S
LTC
IL2007-005
1/4
Woodstock
McHenry
6/U
D
Unknown
C. difficile
C
LTC-hospital
IL2007-009
1/5
Metropolis
Massac
40/160
D,V
Person-person
Norovirus
S
LTC
IL2007-003
1/7
Mcleansboro
Hamilton
15/U
D,V
Person-person
Norovirus G2
C
LTC
IL2007-021
1/8
Scales Mound
Jo Daviess
72/296
D,V
Person-person
Norovirus
S
school
IL2007-030
1/8
Rockford
Winnebago
7/13
D,V
Person-person
Shigella sonnei
C
School-Head
Start
IL2007-010
1/9
Wheeling
Cook
33/U
D,V
Person-person
Norovirus G2
C
LTC
IL2007-020
1/11
Bethalto
Madison
73/186
D,V
Person-person
Norovirus
S
LTC
IL2007-016
1/13
Olney
Richland
88/326
D,V
Person-person
Norovirus G2
C
LTC
IL2007-022
1/15
Rockford
Winnebago
28/U
D,V
Person-person
Norovirus
S
LTC
226
IL2007-019
1/15
Northbrook
Cook
20/U
D,V
Person-person
Norovirus G2
C
LTC
IL2007-018
1/15
Granite City
Madison
39/185
D,V
Person-person
Norovirus G2
S
LTC
IL2007-011
1/15
Chicago
Cook
23/55
D,V
Person-person
Norovirus G2
C
LTC
IL2007-013
1/15
Des Plaines
Cook
20/U
D,V
Person-person
Norovirus
S
Assisted living
IL2007-017
1/16
Trenton
Clinton
31/38
D,V
Person-person
Norovirus G2
S
Assisted living
IL2007-105
1/17
E. St Louis
St Clair
2/10
SSTI
MRSA
C
Worksite
IL2007-014
1/20
Olney
Richland
17/28
D,V
Person-person
Norovirus
C
LTC-hospital
IL2007-069
1/22
Cough, chest
pain,fever
Inhalation
Histoplasmosis
C
Multiple
households
IL2007-026
1/24
Oak Park
Cook
59/64
D,V
Person-person
Norovirus
S
school
IL2007-023
1/27
Elgin
Kane
20/25
D,V
Person-person
Norovirus G2
C
Hospital
IL2007-025
1/30
Greenville
Bond
8/16
D,V
Person-person
Norovirus G2
S
Assisted living
IL2007-035
1/31
Chicago
Cook
36/U
D,V
Person-person
Norovirus G2
C
Hospital
IL2007-033
2/1
Galena
Jo Daviess
55/121
D,V
Person-person
Norovirus G2
C
LTC-hospital
IL2007-032
2/1
Libertyville
Lake
152/610
D,V
Person-person
Norovirus G2
C
LTC
Grundy
3/6
227
IL2007-027
2/3
Rockford
Winnebago
7/U
D,V
Person-person
Norovirus
S
LTC
IL2007-028
2/3
Alton
Madison
37/60
D,V
Person-person
Norovirus G2
C
LTC-hospital
IL2007-031
2/6
Decatur
Macon
14/65
D,V
Person-person
Norovirus G2
S
LTC-hospital
IL2007-034
2/9
Beecher
Will
78/146
D,V
Person-person
Norovirus G2
C
LTC
IL2007-036
2/10
Springfield
Sangamon
21/90
D,V
Person-person
Norovirus G2
C
hospital
IL2007-037
2/12
Wood River
Madison
63/U
D,V
Person-person
Norovirus G2
C
LTC
IL2007-041
2/16
Alton
Madison
24/62
D,V
Person-person
Norovirus G2
C
LTC-Hospital
IL2007-040
2/17
Springfield
Sangamon
13/178
D,V
Person-person
Norovirus
S
LTC
IL2007-045
2/18
Aurora
Kane
33/60
D,V
Person-person
Norovirus G2
C
Assisted living
IL2007-042
2/20
Alton
Madison
89/213
D,V
Person-person
Norovirus G2
C
LTC
IL2007-049
2/23
Springfield
Sangamon
72/136
D,V
Person-person
Norovirus
S
LTC
IL2007-050
2/24
Skokie
Cook
15/128
D,V
Person-person
Norovirus G2
C
LTC
IL2007-046
2/26
Astoria
Fulton
24/65
D,V
Person-person
Norovirus G2
C
LTC
IL2007-052
2/26
Rockford
Winnebago
95/507
D,V
Person-person
Norovirus G1
C
Elementary
school
228
IL2007-053
2/27
Elmhurst
DuPage
6/U
D,V
Person-person
Norovirus
S
LTC-hospital
IL2007-055
2/28
Maryville
Madison
65/190
D,V
Person-person
Unknown
U
LTC
IL2007-043
2/29
Jacksonville
Morgan
49/136
D,V
Person-person
Norovirus G2
C
LTC
IL2007-062
3/3
Pekin
Tazewell
32/146
D,V
Person-person
Norovirus
S
LTC
IL2007-068
3/6
Jacksonville
Morgan
76/135
D,V
Person-person
Norovirus G2
C
Retirement
community
IL2007-066
3/6
Rockford
Winnebago
14/30
D
Person-person
S. sonnei
C
DD facility
IL2007-060
3/7
Joliet
Will
48/140
D,V
Person-person
Norovirus G2
C
LTC
IL2007-063
3/8
Rockford
Winnebago
9/U
D,V
Person-person
Unknown
U
Day care
IL2007-058
3/8
Freeport
Stephenson
21/60
D,V
Person-person
Norovirus G2
S
LTC
IL2007-061
3/9
Springfield
Sangamon
22/149
D,V
Person-person
Norovirus
S
Retirement
community
IL2007-067
3/16
Belleville
St Clair
20/U
D,V
Person-person
Unknown
U
LTC-Hospital
IL2007-065
3/16
Mt Carmel
Wabash
66/186
D,V
Person-person
Norovirus G2
S
LTC
IL2007-071
3/20
Elmhurst
DuPage
4/U
D,V
Person-person
Norovirus
C
LTC-hospital
IL2007-074
3/28
Champaign
Champaign
2/15
D
Person-person
S. sonnei
C
Day care
229
IL2007-192
4/1
Urbana
Champaign
4/27
D
IL2007-082
4/2
Wheaton
DuPage
3/U
SSTI
IL2007-076
4/2
Rockford
Winnebago
27/U
D,V
IL2007-079
4/8
Hardin
Calhoun
57/U
IL2007-057
4/15
Alton
Madison
12/U
S. sonnei
C
Shelter
MRSA
C
High school
Person-person
Unknown
U
LTC
D
Person-person
Norovirus G2
C
LTC
D,V
Person-person
Unknown
U
Office
C
Private homes
Multi-county
57/U
D
Unknown
S. ser.
Muenchen
JJ6X01.0641
Shannon
Carroll
4/12
F, cough
Inhalation
Q fever
C
Slaughter
plant
5/2
West Dundee
Kane
31/126
D,V
Person-person
Norovirus G2
C
Day care
5/4
Highland
Madison
D
Animal contactpoultry
S. ser.
Montevideo
C
Private home
Unknown
Invasive
Streptococcus,
Group A
C
LTC
Norovirus G2
C
Developmenta
lly disabled
facility
MRSA
C
Hospital
IL2007-090
4/15
IL2007-125
5/1
IL2007-086
IL2007-099
IL2007-093
Person-person
5/11
Springfield
Sangamon
IL2007-091
5/11
Skokie
Cook
IL2007-098
5/13
Chester
Randolph
IL2007-094
5/20
Jacksonville
IL2007-116
6/11
Champaign
2/U
2/290
34/52
D,V
Person-person
3/U
SSTI
Morgan
20/36
D,V
Unknown
Unknown
U
University
Champaign
3/75
D
Person-person
S. sonnei
C
Day camp
230
Cook, Lake
5/U
D
Turtles
S. I 4,5,12:b:and paratyphi B
C
Private homes
Moline
Rock Island
6/U
D
Person-person
S. sonnei
C
Day care
7/16
Stillman Valley
Ogle
10/120
V
Unknown
Unknown
U
Girl Scout
camp
IL2007-142
7/24
Palatine
Cook
4/7
SSTI
Person-person
MRSA
C
DD facility
IL2007-152
8/1
Glen Carbon
Madison
8/245
SSTI
Person-person
MRSA
C
Assisted living
IL2007-136
8/5
Great Lakes
Lake
200/1000
D,V
Person-person
Unknown
U
Naval base
IL2007-134
8/6
Springfield
Sangamon
10/U
D,F
Unknown
Enterovirus
S
IL2007-137
8/6
Chicago
Cook
3/U
D,V
Person-person
Norovirus G1
C
Hospital
Drug
treatment
center
IL2007-145
8/17
Rockford
Winnebago
27/204
D,V
Person-person
Norovirus G2
C
Day care
IL2007-151
8/18
Rockford
Winnebago
3/15
D
Poultry contact
Campylobacter
C
Private home
IL2007-139
8/18
Winnebago
14/14
D,V
Person-person
Norovirus G2
C
Private home
IL2007-140
8/6
Coles
6/U
SSTI
Person-person
MRSA
C
University
IL2007-168
8/24
Rock Island
6/U
D
Person-person
S. sonnei
C
School
Multi-organ
Unknown
Enterovirus
(Coxsackie B1)
C
Hospital
S. aureus
C
Hospital
IL2007-197
6/18
IL2007-120
7/11
IL2007-118
IL2007-new
Sept
Charleston
Chicago
Cook
2/U
IL2007-154
9/7
Downers Grove
DuPage
6/U
Non-invasive
Clamp,
suspected
IL2007-169
9/15
Rock Island
Rock Island
4/U
D
Person-person
S. sonnei
C
School
IL2007-170
9/17
Rock Island
Rock Island
8/U
D
Person-person
S. sonnei
C
Day care
IL2007-171
9/30
Rock Island
7/U
D
Person-person
S. sonnei
C
IL2008-028
9/30
2/U
SOB, cough
Inhalation
Histoplasmosis
C
Day care
Bridge
construction
site
IL2007-174
11/7
D,V
Person-person
Norovirus G2
S
School
Peoria/Cook
Normal
Mclean
87/304
231
IL2007-176
11/7
Evanston
Cook
7/52
D,V
Person-person
Norovirus
S
Day careautistic
students
IL2007-178
11/8
Elgin
Kane
5/10
D,V
Unknown
Unknown
U
School
IL2007-189
11/9
Peru
Lasalle
3/U
SSTI
Unknown
MRSA
C
Hospital
IL2007-182
11/14
West Chicago
Dupage
50/U
F,V
Person-person
Norovirus
S
School
IL2007-211
11/24
Springfield
Sangamon
17/U
D,V
Person-person
Norovirus G2
C
Hospital
IL2007-186
11/25
Danforth
Iroquois
26/47
D,V
Person-person
Unknown
U
LTC
IL2007-190
11/29
Normal
Mclean
47/151
D,V
Person-person
Norovirus
S
School
IL2007-196
12/2
Morgan
36/135
D,V
Person-person
Norovirus G2
C
Assisted living
IL2007-195
12/6
DuPage
43/103
D,V
Person-person
Norovirus
S
Day care
IL2007-199
12/6
Cook
46/U
D,V
Norovirus
C
LTC
IL2007-201
12/15
Chicago
Cook
22/U
Person-person
Injection from
contaminated
product
Serratia
marcescens
C
Hospital
IL2007-204
12/12
Freeburg
St Clair
Person-person
Norovirus
S
LTC
C
LTC
Elmhurst
40/165
V
IL2007-208
12/14
Lincolnshire
Lake
18/150
D
Person-person
Norovirus,
unknown type
IL2007-202
12/19
Lebanon
St Clair
42/229
D,V
Person-person
Norovirus G2
S
LTC
IL2007-209
12/31
Sherman
Sangamon
61/207
D,V
Person-person
Norovirus
S
LTC
Note: 1 U=Unknown; 2 D=Diarrhea, V=Vomiting, SSTI=skin and soft tissue infection; 3 S=suspect, C=confirmed; 4
LTC=long-term care.
232
Other incidents of interest, 2007
African tick bite fever
African tick-bite fever is caused by Rickettsia africae and is spread from
tick bites. It is endemic in rural areas of sub-Saharan Africa and in the French
West Indies. Eight French patients developed African tick bite fever in France
after travel to South Africa.
Two probable cases of African tick bite fever were reported in an Illinois
couple traveling to South Africa in June 2007. The husband had fever, headache,
rash and red nodule with a necrotic center on the leg. The wife had myalgias, red
nodule and headache.
Suggested Readings
Roch, N. African tick bite fever in elderly patients:8 cases in French
tourists returning from South Africa. CID 2008;47:e28-e35.
Cosmetic soft-tissue filler illnesses
Soft-tissue fillers are used to augment or enhance the appearance of lips,
breasts, buttocks or other soft tissue. Injections of fillers, especially liquid silicone
by unlicensed practitioners can cause severe adverse reactions. In December
2007, an Illinois resident received an injection from an unlicensed practitioner in
North Carolina. Within an hour of the injection she had headache and nausea
and her urine turned burgundy. She was found to be in acute renal failure and
hemodialysis was initiated. A renal biopsy revealed severe acute tubular
necrosis. She was hospitalized for 13 days in Illinois. Two additional persons
visiting the same facility and receiving injections also developed renal failure.
Suggested readings
Branton, M. Acute renal failure associated with cosmetic soft-tissue filler
injections-North Carolina, 2007. MMWR 2008;57(17):453-456.
Oak leaf gall mites
In 2007, there were numerous reports of bites from oak leaf itch mites.
Outbreaks of Pyemotes herfsi bites occurred in Kansas and Nebraska in 2004. In
2004 pin oaks had midge larvae which resulted in an increase in mites which
consume the larvae. Bites from these mites result in red welts on neck, face,
arms and upper torso. The bites are not usually on legs which distinguishes the
bites from bites from chiggers.
In Illinois complaints began in mid-August. Emergency departments in
Cook and Dupage Counties reported many complaints from patients about these
mites. The mite is called Pyemotes and requires an entomologist experienced
with these mites to identify them. People reported bites on the back, arms and
shoulders several hours after being outdoors. These mites do not carry disease
but may bite people incidentally and inject a neurotoxic venom which results in
itching. The University of Nebraska identified the mite. These mites are most
active when it is greater than 80 F, especially after rains from August to October.
233
It is believed in Illinois that the increase in mites was associated with the
emergence of the 17-year cicada. The mites parasitized the cicada.
Prevention message for 2007 were to remain indoors during time periods
when mite bites are occurring and to keep windows shut from August through
October when mite showers can occur. When working outdoors citizens were
advised to wear long sleeves, long pants and a hat. Persons could choose to use
DEET or picaridin. Persons were advised to avoid direct handling of leaves and
lawn clippings. When persons came inside from the outdoors in areas where the
mites were active, they were to remove clothing and wash the clothes promptly.
In addition, they were advised to take a warm shower when they came inside.
Suggested readings
Zaborski, E.R. 2007 Outbreak of human pruritic dermatitis in Chicago,
Illinois caused by an itch mite, Pyemotes herfsi (Oudemans, 1936) (Acarina:
Heterostigmatai Pyemotid). Illinois Natural History Survey. Technical Report. May
20, 2008.
Eczema vaccinatum in child linked to military father given smallpox
vaccination
A child with eczema vaccinatum, a life-threatening complication of
vaccinia virus infection was reported in March 2007 in a Chicago resident. This
was the first reported case in the United States since 1988. An active duty
military member who had received a first-time smallpox vaccination visited his
home in mid-February, prior to deployment. He had a history of childhood
excema and had household contact with two children, both had contraindications
to vaccination. He spent time with his son who had severe eczema and reported
that his scab had separated prior to the visit and that he had kept it bandaged.
The child developed a generalized papular vesicular rash on the face, neck and
upper extremities and was hospitalized in March. The diagnosis of orthopox DNA
was made at the IDPH laboratory and confirmed at CDC. He was hospitalized for
48 days. The mother also developed vesicular lesions containing orthopox virus.
No other contacts became ill. Environmental swabs from the home were positive.
Suggested readings
Marcinak, J., et. al. Household transmission of vaccinia virus from contact
with a military smallpox vaccinee-Illinois and Indiana, 2007. MMWR 2007;56(19):
478-80.
234
Table 21. Reported Cases of Infectious Disease in Illinois, 2007
Disease
Number
Disease
AIDS/HIV
1,394/1,707
Amebiasis cases, symptomatic
107
Anthrax
Arbovirus infection (WNV, Dengue, SLE,
CE, Chikungunya)
Aseptic meningitis or encephalitis of
unknown etiology
Aseptic meningitis or encephalitis of
known etiology, not arbovirus
Blastomycosis
Botulism
Brucellosis
0
101 WNV, 0
SLE, 0 CE, 0
Dengue, 2
Chikungunya
1,039
Influenza, novel/influenza, pediatric
mortality
Legionnaires disease
Number
1/1
111
Leprosy
1
Leptospirosis
2
Listeriosis
34
170
Lyme disease
137
Malaria
63
Measles
1
1 infant botulism
6
Meningococcal, invasive
149
61
Campylobacteriosis
1,277
Murine typhus
Chickenpox, total
1,091
Mumps
170
Pertussis
199
Chlamydia trachomatis
Cholera
Cryptosporidiosis
55,470
0
205
Psittacosis
Q fever
Cyclospora
3
Rabies, animal/rabies, PHE
Cysticercosis
0
Reye syndrome
Diphtheria
0
Rocky Mountain spotted fever
Ehrlichiosis, human granulocytic
6
Rubella
Ehrlichiosis, human monocytic
Ehrlichiosis, unknown type
E. coli, shiga toxin producing
Foodborne/water/NFNW outbreaks
Giardiasis
Gonorrhea
37
7
131
79/2/103
866
20,813
Guillain Barre syndrome
H. influenzae, invasive disease
Salmonellosis
Shigellosis
S. aureus, vancomycin resistant
Streptococcus, group A, invasive
Streptococcus, group B, invasive (< 3
months)
Streptococcus pneumoniae, invasive
Syphilis, primary or secondary
124
2
0
14
113/440
0
39
1
1,966
781
0
326
75
1,235
464
Tetanus
2
Hantavirus
0
Toxic shock syndrome
9
Hemolytic uremic syndrome
5
Trichinosis
0
Hepatitis A, acute
118
Tuberculosis
Hepatitis B, acute
130
Tularemia
Hepatitis C, acute/Hepatitic C, chronic
Histoplasmosis
16/7,840
123
235
521
1
Typhoid fever cases
24
Yersiniosis
24
Methods
Health care professionals - including infection control nurses, physicians
and school nurses - are required by Illinois law to report specific infectious
diseases to their local health department. There are 95 local health departments
in Illinois. Some serve a city or district, some serve the entire county and some
serve residents of several counties. The local health department reports cases to
the Illinois Department of Public Health, which, in turn, reports all nationally
notifiable diseases to the United States Centers for Disease Control and
Prevention (CDC). All information about patients is confidential; case reports to
the CDC do not identify patients.
This annual report includes only cases reported to the Department.
Therefore, these annual numbers will underestimate the total number of
cases of each disease in the state. Some patients with disease do not seek
medical attention, some may not have the necessary testing done for a
diagnosis, or the medical provider may not report the case to public health
authorities. Also, to standardize reporting in the state, only cases that are
reported and meet the case definition for that disease are included in case
counts. For some diseases, a case definition is listed for both confirmed and
probable cases. For all diseases except HIV/AIDS, the number of cases reported
in a year is closed out in mid-May of the following year. If cases from the
preceding year are reported after the closing date, they are not included in the
preceding year’s numbers. For HIV/AIDS, there are two categories: number of
cases reported in a given year versus number of cases diagnosed in a given
year. The number of cases diagnosed in a given year is continually updated even
if there is an extremely long delay in reporting a case. Therefore, the numbers for
diagnosed AIDS cases in 2007 may be updated.
Reportable diseases diagnosed in college students living away from home
and in residents of prisons, long-term care or other residential facilities are
reported in the jurisdiction where the patient resides at the time of diagnosis. This
results in attributing to rural counties that have a college or prison high incidence
rates of certain diseases. Persons who are residents of Illinois but are not
citizens of the United States may be counted. Persons who are visiting the U.S.
and become clinically ill with malaria are counted in malaria statistics. Residents
of other states who become ill in Illinois are not counted in this state’s statistics
but are transferred to the state of residence. However, temporary workers in
Illinois are counted in Illinois statistics.
The Illinois population used to calculate incidence rates and race and
ethnicity proportions in past editions of this document was from the 1990
Modified Age-Race-Sex (MARS) data. According to the United States Census
Bureau, Illinois’ population grew from 11,430,602 in 1990 to 12,419,293 in 2000.
The percentage of the population in the various age groups changed very little
between the 1990 MARS data and the 2000 census. However, the racial and
ethnic distribution did change substantially between 1990 and 2000. In 1990, the
state’s population was 82 percent white, 15 percent African American, 2 percent
Asian and 1 percent other or mixed races. In 2000, the census found the
following percentages: 73 percent white, 15 percent African American, 3 percent
236
Asian and 8 percent other or mixed races. Those indicating Hispanic ethnicity
accounted for 8 percent of the state’s population in 1990; in 2000, this proportion
had increased to 12 percent. In 2000, 49 percent of the population was male and
51 percent was female. The following table shows the age distribution of the
Illinois population as determined by the 2000 census.
Census
numbers used
for 2000
annual report
% of population
<1 year
173,373
1
1-4 years
703,176
6
5-9 years
929,858
7
10-19 years
1,799,099
14
20-29 years
1,742,602
14
30-59 years
5,108,274
41
>59 years
1,962,911
15
Age category
TOTAL
12,419,293
Where it was deemed useful, graphs were produced showing the number
of cases by month, the number of cases by year since 2002 and the age
distribution. Incidence rates were calculated for some diseases. Incidence rate
was calculated by taking the number of cases in a category, dividing by
population size from 2000 census data and multiplying by 100,000. If an annual
incidence rate was calculated for the period 2003 to 2007, it was reached by
taking the number of cases reported from 2003 through 2007, dividing by the
population and multiplying by 100,000; it was then annualized by dividing by five.
The reports for each disease were generated from the INEDSS database.
The criteria used were year reported = 2007. For diseases where asymptomatic
cases do not meet the case definition (hepatitis A and amebiasis) these
laboratory confirmed cases were not included in the detailed information in the
disease information. The epidemiologic information presented for each disease is
for 2007 only, unless otherwise specified. For some diseases, where the number
of cases by year was low, information may have been combined for multiple
years to allow demonstration of trends by month and age. When the case
population differed from the Illinois population in the racial distribution, a chisquare test for a significant difference in proportions was done using the Epi-Info
software package.
Suggested reading lists are provided for some diseases.
237