Jan 29, 2018 - influenza testing (PCR) to the San Antonio Metropolitan Health District's (Metro Health) public health la
Epidemiology Program 2509 Kennedy Circle, Bldg 125 San Antonio, TX 78235 Phone: 210.207.8876 Fax: 210.207.8807
Bexar County Influenza Surveillance Report, 2017-2018 Season; 2018 MMWR Week 3 (Jan. 14 – Jan. 20, 2018)
Summary
Influenza activity remains high across San Antonio and Bexar County. Compared to the previous week, the percentage of patient visits due to influenza-like illness (ILI) and the percentage of specimens testing positive for influenza reported by public health and hospital laboratories has marginally decreased. No influenza-associated pediatric deaths were reported this week. Two ILI or influenza-associated outbreaks were reported this week compared to five last week. Table 1: Summary of Recent Bexar County Influenza and Influenza-like Illness (ILI) Activity
Percentage of specimens positive for influenza by hospitals and public health laboratory + Percentage of visits due to ILI Number of variant/novel influenza infections Number of Pediatric influenza deaths Influenza Activity Code
Percent Change from Previous Week
Current Week 3
Previous Week 2
↓0.5%
39.7
39.9
Data Cumulative since October 1, 2017 (Week 40) 21.7
↓7.1%
10.4
11.2
5.6
No change No change
0 0
0 0
0 1
-
Widespread
Widespread
-
Note: Data included in this table have been updated since last week’s flu report with any new reports received. + Based on ILINet data
U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet)
Information on patient visits to health care providers for influenza-like illness is collected through Bexar County. Health care providers voluntarily report this information to ILINet. Figure 1: Percentage of Visits Due to ILI Reported by Bexar County ILINet Participants 2014-2018 Seasons
Bexar County % ILI 25
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 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
% ILI
20
CDC Week Bexar 2017-2018
2016-2017
2015-2016
2014-2015
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Figure 2: Percentage of Visits Due to ILI Reported by ILINet Participants, Texas and Bexar County, 2017-2018
12 10
% ILI
8 6 4 2 0 40
41
42
43
44
45
46
47
48
49
50
51
52
1
2
3
CDC Week Bexar County
Texas
Texas Baseline
Laboratory Results Hospital and Public Health Laboratory Testing Hospital laboratories voluntarily report influenza tests (antigen, culture, and PCR) to the National Respiratory and Enteric Virus Surveillance System (NREVSS). Providers throughout Bexar County also submit specimens for influenza testing (PCR) to the San Antonio Metropolitan Health District’s (Metro Health) public health laboratory. The results reported by Texas NREVSS participants and Metro Health for the current week are summarized in the table below. Table 2: Influenza testing performed in Bexar County for the Current and Previous Week
Current Week 3
Previous Week 2
639 254 (39.7%)
774 309 (39.9%)
Cumulative since October 1, 2017 (Week 40) 10,430 2,257 (21.7%)
Influenza Type A
188 (74%)
261 (84.5%)
1,965 (87.1%)
H1N1 H3N2 Subtyping not performed/unable to subtype Influenza Type B
16 (8.5%) 67 (34%) 105 (55.9%) 66 (26%)
23 (8.8%) 97 (37.2%) 141 (54%) 48 (15.5%)
Number of specimens tested Number of positive specimens Positive specimens by type/subtype (n, %)
195 (9.9%) 802 (40.8%) 968 (49.3) 292 (12.9%)
Note: Data included in this table is voluntarily submitted weekly via NREVSS and Metro Health laboratory
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50.%
Number of tests positive for influenza
350
45.%
300
40.%
250
35.% 30.%
200
25.%
150
20.% 15.%
100
10.%
50
5.%
0
0.% 40
41
42
43
44
45
46
47
48
49
50
51
52
1
2
Percentage of tests positive for influenza
Figure 3: Number and Percentage of PCR Tests Positive for Influenza by Type and Subtype, Bexar County, 2017-2018
3
CDC Week H1N1
H3N2
Flu A (not subtyped)
Flu B
Percent flu positive
Sentinel Provider Laboratory Testing Providers throughout Bexar County also submit test results from influenza rapid testing to the San Antonio Metropolitan Health District on a voluntary basis. These sites are recruited to send this information on a weekly basis. The results from the participating providers are summarized in the table below (Table 3). Table 3: Influenza testing performed by Bexar County Sentinel Providers
Current Week 3 Number of providers reporting flu tests Number of positive specimens
Previous Week 2
Cumulative since October 1, 2017 (Week 40)
12 741
12 627
4,056
530 (71.5%) 14 (2.6%) 63 (11.9%) 103 (19.4) 211 (28.5)
527 (84.1%) 20 (3.8%) 85 (16.1%) 141 (22.5) 100 (15.9)
3,384 (83.4%) 181 (5.3%) 684 (20.2%) 570 (16.8%) 672 (16.6%)
Positive specimens by type/subtype (n, %) Influenza Type A
H1N1 H3N2 Subtyping not performed/unable to subtype Influenza Type B
Note: Data included in this table is voluntarily submitted weekly by our sentinel flu providers. This data may not be comparable to previous flu seasons because providers vary by year.
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P&I Mortality Surveillance Data Pneumonia and influenza (P&I) death data are obtained from death certificates of Bexar County residents whose underlying or contributing cause(s) of death is reported as pneumonia or influenza. Table 4: Bexar County P&I Deaths Occurring October 1, 2017- January 20, 2018 by Age Group
Age Category (years) 0-4 5-17 18-49 50-64 65+
Number of P&I Deaths+ 0
