Influenza Surveillance Summary
Week 5: January 29, 2017 – February 4, 2017
Influenza surveillance for Kane County Health Department includes the collection of data from hospital emergency
rooms, laboratories, and public schools. Our participants have reported the following aggregate measures:

Among four reporting hospital emergency rooms, 5.5% of visits were for influenza-like illness (ILI).

During Week 5, labs reported that 282 of 908 (31.1%) of specimens tested for influenza were positive. Of these
282 specimens:
- 186 (66.0%) were positive for Influenza A
- 93 (33.0%) were positive for Influenza B
- 3 (1.1%) were positive for Influenza AB
No other specimen tested positive for the week ending February 4, 2017.

The ILI absenteeism rate for public schools in Kane County was 0.38%. No school was closed due to increased ILI
activity.

As of the week ending February 4, there have been 5 cases of influenza-related ICU admissions reported to the
health department. No influenza-associated pediatric deaths were reported.

To date, no outbreaks of influenza have been reported in Long-Term Care/Assisted Living facilities in Kane
County.
The health department would like to thank the participating hospitals, laboratories, individual schools, and school
districts that provide the data that make this monitoring possible.
1Influenza-like
illness (ILI) is defined as fever > 100°F with cough or sore throat without other known cause
influenza testing cannot distinguish influenza infections caused by novel influenza A viruses. The sensitivity of this type of testing has been
shown to range between 20-100% for seasonal influenza viruses. A negative result does not exclude influenza virus infection.
*Data are provisional
2Rapid
1
Kane County Health Department Influenza-Like-Illness Surveillance:
Emergency Room Visits
Participating Emergency Rooms: N=4
20%
18%
PERCENT OF ER VISITS
16%
14%
12%
10%
8%
5.5% of ER Visits
6%
4%
2%
2009-10
2010-11
*2014 is the only year with 53 weeks
2011-12
WEEK NUMBER
2012-13
2013-14
2014-15
2015-16
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
*53
52
51
50
49
48
47
46
45
44
43
42
41
40
0%
2016-17
During Week 5, 5.5% of reported hospital emergency room visits was for influenza-like illness (ILI).1
Each week, data for the 2016-17 season will be presented with data from the previous flu seasons to show the trend of
ER visits for ILI over time.
1Influenza-like
illness (ILI) is defined as fever > 100°F with cough or sore throat without other known cause
influenza testing cannot distinguish influenza infections caused by novel influenza A viruses. The sensitivity of this type of testing has been
shown to range between 20-100% for seasonal influenza viruses. A negative result does not exclude influenza virus infection.
*Data are provisional
2Rapid
2
Kane County Health Department Influenza-Like-Illness Surveillance:
Percent of ILI Visits by Age
20%
180
18%
160
16%
140
14%
120
12%
100
10%
80
8%
60
5.5% of ER Visits
6%
40
4%
20
2%
0
% OF ER VISITS FOR ILI
NUMBER OF PATIENT ER VISITS FOR ILI
Participating Emergency Rooms: N=4
200
0%
40 41 42 43 44 45 46 47 48 49 50 51 52 1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17
WEEK NUMBER
ILI 0-4
ILI 5-24
ILI 25-64
ILI 65+
% of ER visits
Visits for influenza-like illness to reporting emergency rooms during Week 5 had the following age distribution:
-
0-4 years: 27.3% of all ILI visits
5-24 years: 38.0% of all ILI visits
25-64 years: 27.3% of all ILI visits
65+ years: 7.5% of all ILI visits
Throughout the season, KCHD will provide updated information on the total number of people visiting the emergency
room for ILI, and what age groups make up those visits. This week, 5.5% of all visits to reporting emergency rooms were
for ILI.
1Influenza-like
illness (ILI) is defined as fever > 100°F with cough or sore throat without other known cause
influenza testing cannot distinguish influenza infections caused by novel influenza A viruses. The sensitivity of this type of testing has been
shown to range between 20-100% for seasonal influenza viruses. A negative result does not exclude influenza virus infection.
*Data are provisional
2Rapid
3
Kane County Health Department Influenza-Like-Illness Surveillance:
Rapid Influenza Tests
Participating Laboratories: N=6
300
45%
40%
35%
31.1% of tests were
positive
200
30%
25%
150
20%
100
15%
10%
50
PERCENT OF TESTS POSITIVE FOR INFLUENZA
NUMBER OF POSITIVE SPECIMENS BY INFLUENZA TYPE
250
5%
0
0%
40 41 42 43 44 45 46 47 48 49 50 51 52 1
A
B
2
3
4
WEEK NUMBER
AB
5
6
7
8
9 10 11 12 13 14 15 16 17
Positive%
Kane County Labs (6)
Week: 5
Number
Percent
Specimens Tested
908
Specimens Positive
282
31.1%
Positive Specimens by Type
Influenza A
186
66.0%
Influenza B
93
33.0%
Influenza AB
1
1.1%
Unknown
0
0.0%
1Influenza-like
illness (ILI) is defined as fever > 100°F with cough or sore throat without other known cause
influenza testing cannot distinguish influenza infections caused by novel influenza A viruses. The sensitivity of this type of testing has been
shown to range between 20-100% for seasonal influenza viruses. A negative result does not exclude influenza virus infection.
*Data are provisional
2Rapid
4
Kane County Health Department Influenza-Like-Illness Surveillance:
ILI-Related School Absenteesim
1.60%
1.40%
% STUDENTS ABSENT DUE TO ILI
1.20%
1.00%
0.80%
0.60%
0.38% of students absent
for ILI
0.40%
0.20%
0.00%
2009-10
2010-11
2011-12
WEEK NUMBER
2012-13
2013-14
2014-15
2015-16
2016-17
*2014 is the only year with 53 weeks
**Schools closed for holiday
The ILI absenteeism rate for public schools in Kane County was 0.38%. No school was closed due to increased ILI activity.
1Influenza-like
illness (ILI) is defined as fever > 100°F with cough or sore throat without other known cause
influenza testing cannot distinguish influenza infections caused by novel influenza A viruses. The sensitivity of this type of testing has been
shown to range between 20-100% for seasonal influenza viruses. A negative result does not exclude influenza virus infection.
*Data are provisional
2Rapid
5
No Activity:
No laboratory-confirmed cases of influenza and no reported increase in the number of cases of ILI.
Sporadic:
Small numbers of laboratory-confirmed influenza cases or a single laboratory-confirmed influenza
outbreak has been reported, but there is no increase in cases of ILI.
Local:
Outbreaks of influenza or increases in ILI cases and recent laboratory-confirmed influenza in a single
region of the state.
Regional:
Outbreaks of influenza or increases in ILI and recent laboratory confirmed influenza in at least two but
less than half the regions of the state with recent laboratory evidence of influenza in those regions.
Widespread:
Outbreaks of influenza or increases in ILI cases and recent laboratory-confirmed influenza in at least half
the regions of the state with recent laboratory evidence of influenza in the state.
1Influenza-like
illness (ILI) is defined as fever > 100°F with cough or sore throat without other known cause
influenza testing cannot distinguish influenza infections caused by novel influenza A viruses. The sensitivity of this type of testing has been
shown to range between 20-100% for seasonal influenza viruses. A negative result does not exclude influenza virus infection.
*Data are provisional
2Rapid
6