2016–2017 Influenza Season
Surveillance Week 41
Dallas County Health and Human Services
Ending 10/15/16
Epidemiologic Summary
• Influenza activity remains low in Dallas County with 1.3% of tests returning positive during week 41.
Nationally, 1.3% of specimens reported to CDC were positive for influenza.
• Daily numbers of emergency department visits for influenza-like illness in Dallas County remain at
baseline levels and three influenza-associated hospitalizations were reported during week 41.
• RSV activity remains low with 1.6% of tests from area surveillance sites testing positive.
Table 1. Influenza Surveillance Summary: Dallas County Providers, Hospitals and
Viral Labs: September 11, 2016 – October 15, 2016
Week Ending
9/17*
9/24*
10/1*
10/8*
10/15*
CDC Week
37
38
39
40
41
9/11 –
Present
354
405
422
484
609
2274
21
Influenza tests performed weekly
Total positive influenza
tests1
2
5
3
3
8
0.6
1.2
0.7
0.6
1.3
Positive influenza A tests2
1
3
2
2
1
9
Positive influenza B tests
1
2
1
1
7
12
Non-differentiated influenza tests3
0
0
0
0
0
0
0
1
1
2
3
7
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Percent positive influenza tests
Influenza
hospitalizations4
Confirmed pediatric
Confirmed adult
deaths5
deaths6
Possible influenza-associated
deaths7
*Indicates preliminary results which are subject to change with late-arriving data from surveillance sites designated for DCHHS’
seasonal influenza program
1
Includes positive rapid antigen, PCR, DFA, or culture results
2
Further subtyping is performed only for specimens referred by institutions for PCR-testing
3
Non-differentiated refers to rapid test results which did not differentiate between influenza A and B
4
Reflects all influenza-associated hospitalizations reported from hospitals located within Dallas County by week of positive test
5
Confirmed influenza-associated deaths of Dallas County residents <18 years of age
6
Confirmed influenza-associated deaths as defined by a positive laboratory test, compatible symptoms, and clear progression
from illness to death, or determination by the County Medical Examiner’s office (ME) of no alternate cause of death
7
Possible influenza-associated deaths are defined as cases with laboratory-confirmed influenza, but pending final autopsy
results for determination of primary cause of death
Table 2. Influenza-associated Pediatric and Adult Deaths, Dallas County:
2011–2017 Seasons
Confirmed
Deaths
2011–2012
2012–2013
2013–2014
2014–2015
2015–2016
2016-2017
Pediatric
1
3
3
0
1
0
Adult
0
6
55
19
14
0
Data source(s): Reports of confirmed influenza-associated deaths, as defined above.
Page 1 of 4
DCHHS 2016–2017 Influenza Season
Surveillance Week 41
Ending 10/15/16
Figure 1. Percent Positive Influenza Tests by Week, Dallas County: 2014–2016
Seasons
35
30
2014-2015
Percent Positive
25
2015-2016
2016-2017
20
15
10
5
0
35 37 39 41 43 45 47 49 51 53 2
4
6
8 10 12 14 16 18 20 22 24 26 28 30
CDC Week
Number of ILI Reports
Figure 2. Syndromic Surveillance of Emergency Department Visits for Influenzalike Illness (ILI), Dallas County: September 1, 2014 – October 15, 2016
Data alert
Data warning
Data normal
Data source: 18 emergency departments in Dallas County hospitals participating in the Electronic Surveillance System for the Early
Notification of Community-based Epidemics (ESSENCE) voluntarily reporting the numbers of persons presenting with self-reported
chief complaints of ILI.
Page 2 of 4
DCHHS 2016–2017 Influenza Season
Surveillance Week 41
Ending 10/15/16
Table 3: Non-Influenza Respiratory Virus Testing by North Texas Laboratories
Reported to NREVSS, Week 41
Virus
Number of
Laboratories
Reporting
Tests
Performed
Total Positive
Tests
Percentage of
Tests Positive
Adenovirus (respiratory)
HMPV
3
3
197
141
3
0
1.5%
0.0%
Parainfluenza virus
3
197
13
6.6%
Rhinovirus/enterovirus
RSV
3
3
188
247
54
4
28.7%
1.6%
Data source: National Respiratory and Enteric Virus Surveillance System (NREVSS) and hospitals reporting directly to DCHHS
Figure 3. Number and Percent Positive RSV Rapid Antigen and PCR Tests by Week,
NREVSS Surveillance Data, North Texas: August 22, 2015 – October 15, 2016
35
30
# Positive 2015-2016
200
# Positive 2016-2017
25
% Positive 2015-2016
150
20
% Positive 2016-2017
15
100
10
50
5
0
Percent Positive RSV Tests
Number of Positive RSV Tests
250
0
33
35
37
39
41
43
45
47
49
51
53
2
4
6
8
10
12
14
16
18
20
CDC Week
Data source: National Respiratory and Enteric Virus Surveillance System (NREVSS) and hospitals reporting directly to DCHHS
Table 4. Number and Percent Positive RSV Rapid Antigen and PCR Tests by Week,
NREVSS Surveillance Data, North Texas: August 20, 2016 – October 15, 2016
Week Ending
9/3
9/10
9/17
9/24
10/1
10/8
10/15
CDC Week
35
36
37
38
39*
40*
41*
8/20–
Present
RSV tests performed weekly
143
157
198
220
212
228
247
1677
Total positive RSV tests
0
4
4
3
3
5
4
26
Percent positive RSV tests
0
2.5
2.0
1.2
1.4
2.2
1.6
*Indicates preliminary results which are subject to change as adjustments are made for late-arriving data
Data source: National Respiratory and Enteric Virus Surveillance System (NREVSS)
Page 3 of 4
DCHHS 2016–2017 Influenza Season
Surveillance Week 41
Ending 10/15/16
Please report any of the following patients to DCHHS within 1 working day:

Hospitalized patients with influenza (any subtype). Confirmation can be by any
laboratory test, rapid antigen, culture, PCR, DFA/IFA, or performed in an outpatient or
inpatient laboratory.

Deaths of persons with confirmed influenza (any subtype). We are requesting all
pediatric influenza-associated deaths to be reported immediately to facilitate specimen
procurement and testing.

Suspected influenza infections involving institutional outbreaks or a resident of any Long
Term Care facility (please report immediately).
Phone: (214) 819-2004
Email: [email protected]
Page 4 of 4