Weekly Influenza & Respiratory
Illness Activity Report
A summary of influenza surveillance indicators prepared by the Division of Infectious Disease Epidemiology Prevention & Control
Week Ending March 25, 2017 | WEEK 12
All data are preliminary and may change as more information is received
Minnesota Influenza Geographic Spread
No Activity
Sporadic
Local
Regional
Widespread
During the week ending March 25, 2017 (Week 12),
surveillance indicators showed
widespread geographic spread of influenza.
Since the start of the influenza season,
2 pediatric influenza-related deaths
have been reported.
Based on CDC’s Activity Estimates Definitions: http://www.cdc.gov/flu/weekly/overview.htm
Minnesota Influenza Surveillance:
http://www.health.state.mn.us/divs/idepc/diseases/flu/stats/
Weekly U.S. Influenza Surveillance Report:
http://www.cdc.gov/flu/weekly/
World Health Organization (WHO) Surveillance: http://www.who.int/influenza/surveillance_monitoring/updates/en/
Neighboring states’ influenza information:
Iowa
http://www.idph.state.ia.us/IdphArchive/Archive.aspx?channel=FluReports
Wisconsin
http://www.dhs.wisconsin.gov/communicable/influenza/surveillance.htm
North Dakota http://www.ndflu.com/default.aspx
South Dakota http://doh.sd.gov/diseases/infectious/flu/
Minnesota Department of Health
651-201-5414 or 1-877-676-5414
www.health.state.mn.us
3/30/2017
Hospitalized Influenza Surveillance
Hospitalized influenza cases are based on disease reports of laboratory-positive influenza (via DFA, IFA, viral culture, EIA, rapid test, paired
serological tests or RT-PCR) and specimens from hospitalized patients with acute respiratory illness submitted to MDH-PHL by hospitals and
laboratories. Due to the need to confirm reports and reporting delays, consider current week data preliminary.
Hospitalized Influenza Cases by Type
Minnesota (FluSurv-NET*)
500
Current week
400
B (Yamagata)
B (Victoria)
A (not subtyped)
A H3
350
A H1 (unspecified)
A (H1N1)pdm09
300
A (H1N2v)
A (H3N2v)
250
A&B
200
Unknown
150
100
Number of Hospitalizations
B (no genotype)
450
Number of Hospitalizations
Hospitalized Influenza Cases by Season, Minnesota
(FluSurv-NET*)
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
2011-12
2012-13
2013-14
Current week
2015-16
2016-17
40 42 44 46 48 50 52 2 4 6 8 10 12 14 16 18 20
MMWR Week
50
0
2014-15
40 42 44 46 48 50 52 2
4
6
8 10 12 14 16 18 20
MMWR Week
Hospitalizations
this week
Hospitalizations
last week
Total hospitalizations
(to date)
177
250
2,882
*Influenza Surveillance Network
Season
2011-2012
2012-2013
2013-2014
2014-2015
2015-2016
2016-2017
Total hospitalizations
(historic)
556
3,068
1,540
4,138
1,541
2,882 (to date)
Minnesota Department of Health Weekly Influenza & Respiratory Activity Report for Week Ending March 25, 2017 | WEEK 12
2
Hospitalized Influenza Surveillance (continued)
Number of Influenza Hospitalizations and Incidence by
Region, Minnesota
October 2, 2016 – March 25, 2017
2000
225.0
200.0
1750
175.0
1500
150.0
1250
125.0
1000
100.0
750
500
49.1
250
59.4
42.6
62.5
21.7
55.6
56.2
75.0
32.5
50.0
25.0
0.0
0
Number of Hospitalizations
Number of Hospitalizations
Incidence (cases) per
100,000 Persons
2250
200.0
1750
175.0
1500
150.0
1250
125.0
1000
100.0
750
500
250
75.0
44.3
20.0
13.5
13.9
0-4
5-24
25-49
50.0
25.0
50-64
65+
0.0
Age Group (years)
Region
Central
Metro
Northeast
Northwest
South Central
Southeast
Southwest
West Central
250.0
225.0
Incidence (cases) per
100,000 Persons
2000
0
Region
232.5
# of hospitalizations
Hospitalizations per 100,000 Persons
2250
2500
250.0
Hospitalizations per 100,000 Persons
# of hospitalizations
2500
Number of Influenza Hospitalizations and Incidence by
Age, Minnesota
October 2, 2016 – March 25, 2017
Hospitalizations
this week
Total
(to date)
15 (8%)
126 (71%)
6 (3%)
2 (1%)
9 (5%)
15 (8%)
3 (2%)
1 (1%)
358 (12%)
1,693 (59%)
139 (5%)
34 (1%)
182 (6%)
275 (10%)
125 (4%)
76 (3%)
Median age (years)
at time of admission
73.0
Minnesota Department of Health Weekly Influenza & Respiratory Activity Report for Week Ending March 25, 2017 | WEEK 12
3
Respiratory Disease Outbreak Surveillance
School Outbreaks
K-12 schools report an outbreak of influenza-like illness (ILI) when the number of students absent with ILI reaches 5% of total enrollment or
three or more students with ILI are absent from the same elementary classroom.
Number of influenza-like illness outbreaks
Influenza-like Illness (ILI) in Schools by Season
300
2012-13
2013-14
2014-15
250
2015-16
2016-17
200
150
Current week
100
50
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 18 19 20 21
MMWR Week
New school
outbreaks this week
New school
outbreaks last week
Total this season
(to date)
40
23
341
Minnesota Department of Health Weekly Influenza & Respiratory Activity Report for Week Ending March 25, 2017 | WEEK 12
4
Respiratory Disease Outbreak Surveillance (continued)
Long-Term Care (LTC) Outbreaks
LTC facilities report to MDH when they suspect an outbreak of influenza in their facility. Laboratory-confirmed outbreaks are reported here.
Confirmed Influenza Outbreaks in LTC by Season
70
Number of lab-confirmed outbreaks
65
2012-13
60
2013-14
55
2014-15
50
2015-16
45
2016-17
40
35
30
25
Current week
20
15
10
5
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 18 19 20 21
MMWR Week
New LTC outbreaks
this week
New LTC outbreaks
last week
Total this season
(to date)
7
11
136
Minnesota Department of Health Weekly Influenza & Respiratory Activity Report for Week Ending March 25, 2017 | WEEK 12
5
Sentinel Provider Surveillance (Outpatients)
MDH collaborates with healthcare providers who report the total number of patients seen and the total number of those patients presenting to
outpatient clinics with influenza-like illness.
Percentage of Persons Presenting to Outpatient Clinics with Influenza-Like Illness (ILI)
9
2012-13
Percent with Influenza-like Illness
8
2013-14
2014-15
7
Current week*
6
2015-16
2016-17
5
4
3
2
1
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 18 19 20 21
MMWR Week
% of outpatients with
ILI this week
% of outpatients with
ILI last week
4.93%
4.27%
*Indicates current week-data may be
delayed by 1 or more weeks
Minnesota Department of Health Weekly Influenza & Respiratory Activity Report for Week Ending March 25, 2017 | WEEK 12
6
Laboratory Surveillance
The MN Lab System (MLS) Laboratory Influenza Surveillance Program is made up of more than 310 clinic- and hospital-based laboratories,
voluntarily submitting testing data weekly. These laboratories perform rapid testing for influenza and Respiratory Syncytial Virus (RSV).
Significantly fewer labs perform PCR testing for influenza and three also perform PCR testing for other respiratory viruses. MDH-PHL provides
further characterization of submitted influenza isolates to determine the hemagglutinin serotype to indicate vaccine coverage. Tracking the
laboratory results assists healthcare providers with patient diagnosis of influenza-like illness and provides an indicator of the progression of the
influenza season as well as prevalence of disease in the community.
Specimens Positive for Influenza by Molecular Testing*, by Week
450
Current week
A (not subtyped)
400
A H3
350
A (H1N1) pdm09
2013-14 % + by PCR
300
2014-15 % + by PCR
250
2015-16 % + by PCR
2016-17 % + by PCR
200
150
35
30
25
20
15
10
100
5
50
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 18 19 20 21
MMWR Week
% molecular tests
positive this week
% molecular tests
positive last week
26.1%
22.1%
Percent of positive molecular tests
Number of positive molecular tests
B
0
*Beginning in 2016-17, laboratories report
results for rapid molecular influenza tests
in addition to RT-PCR results
Minnesota Department of Health Weekly Influenza & Respiratory Activity Report for Week Ending March 25, 2017 | WEEK 12
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Laboratory Surveillance (continued)
MLS Laboratories – Influenza Testing
MLS Laboratories – RSV Testing
Specimens Positive by Influenza Rapid Antigen Test, by Week
Specimens Positive by RSV Rapid Antigen Test, by Week
Number of Positive Influenza Specimens
Current week
2013-14 % +
45
2014-15% +
40
2015-16 % +
35
2016-17 % +
30
25
20
15
10
5
40 42 44 46 48 50 52 2 4 6 8 10 12 14 16 18 20
MMWR Week
Region
Northeast
South Central
Southwest
Southeast
Metro
Central
West Central
Northwest
State (overall)
0
% rapid antigen influenza tests +
(current week)
23%
34%
27%
34%
34%
30%
26%
26%
31%
240
Number +
220
2013-14 % +
200
2014-15 % +
180
160
2015-16 % +
2016-17 % +
140
Current week
120
100
80
60
40
20
0
40 42 44 46 48 50 52 2 4 6 8 10 12 14 16 18 20
MMWR Week
Region
Northeast
South Central
Southwest
Southeast
Metro
Central
West Central
Northwest
State (overall)
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Percentage of Rapid Antigen RSV Tests Positive
A/B+ (2015-16 Season)
50
Percentage of Rapid Antigen Influenza Tests Positive
A+ (2015-16 Season)
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
Number of Positive RSV Tests
B+ (2015-16 Season)
% rapid antigen RSV tests +
(current week)
42%
11%
32%
0%
11%
16%
21%
8%
17%
Minnesota Department of Health Weekly Influenza & Respiratory Activity Report for Week Ending March 25, 2017 | WEEK 12
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Laboratory Surveillance (continued)
Minnesota Influenza Incidence Surveillance Project (MIISP)
Positive Respiratory Pathogens by PCR, by MMWR Week
30
Influenza B
Influenza A H3
Influenza A (H1N1) pdm09
Influenza A Unspecified
Influenza C
RSV
Human Metapneumovirus
Rhinovirus/Enterovirus
Adenovirus
Coronavirus NL63
Coronavirus OC43
Coronavirus 229E
Coronavirus HKU1
Parainfluenza-1
Parainfluenza-2
Parainfluenza-3
Parainfluenza-4
Number Positive by RT-PCR
25
20
15
10
5
0
30
32
34
36
38
40
42
44
46
48
50
52 1 2
4
6
8
10
12
14
16
18
20
MMWR Week*
*Indicates current week-data may be delayed by 2 or more weeks
Minnesota Department of Health Weekly Influenza & Respiratory Activity Report for Week Ending March 25, 2017 | WEEK 12
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Laboratory Surveillance (continued)
Severe Acute Respiratory Surveillance (SARI) - Inpatients
Number Positive by RT-PCR
Positive Respiratory Pathogens by PCR, by MMWR Week
120
115
110
105
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
Parainfluenza 4
Coronavirus 229E
Human Metapneumovirus
Influenza B
Bocavirus
32
34
36
38
40
Parainfluenza 3
Coronavirus OC43
RSV
Legionella
42
44
*Indicates current week-data may be delayed by 2 or more weeks
46
Parainfluenza 2
Coronavirus NL63
Influenza A Unspecified
Mycoplasma pneumoniae
48
50
52
2
4
Parainfluenza 1
Adenovirus
Influenza A (H1N1) pdm09
Chlamydophila pneumoniae
6
8
10
12
14
Coronavirus HKU1
Rhinovirus/Enterovirus
Influenza A H3
Influenza C
16
18
20
20
MMWR Week*
Minnesota Department of Health Weekly Influenza & Respiratory Activity Report for Week Ending March 25, 2017 | WEEK 12
10
Weekly U.S. Influenza Surveillance Report
National Influenza Surveillance (CDC): http://www.cdc.gov/flu/weekly/
During week 11 (March 12-18, 2017), influenza activity decreased, but remained elevated in the United States.
Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 11 was influenza A (H3). The percentage of
respiratory specimens testing positive for influenza in clinical laboratories decreased.
Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was above the system-specific epidemic threshold in the National
Center for Health Statistics (NCHS) Mortality Surveillance System.
Influenza-associated Pediatric Deaths: Two influenza-associated pediatric deaths were reported.
Influenza-associated Hospitalizations: A cumulative rate for the season of 50.4 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was
reported.
Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 3.2%, which is above the national baseline of 2.2%. Seven of ten regions
reported ILI at or above their region-specific baseline levels. 12 states experienced high ILI activity; six states experienced moderate ILI activity; nine states experienced low
ILI activity; New York City, Puerto Rico, and 23 states experienced minimal ILI activity; and the District of Columbia had insufficient data.
Geographic Spread of Influenza: The geographic spread of influenza in 36 states was reported as widespread; Guam, Puerto Rico and 10 states reported regional activity; the
District of Columbia and two states reported local activity; two states reported sporadic activity; and the U.S. Virgin Islands reported no activity.
Influenza-Like Illness (ILI) Activity Level Indicator Determined by Data Reported to ILINet
2016-2017 Influenza Season Week 11 ending March 18, 2017
Minnesota Department of Health Weekly Influenza & Respiratory Activity Report for Week Ending March 25, 2017 | WEEK 12
11