2008 - 2009 Texas Influenza Surveillance Information
Influenza Surveillance Report for MMWR Week 2
The influenza (flu) activity level for Texas for the week ending January 17, 2009 was “regional.” Regional activity indicates that two or more but less than half of the regions in the state are experiencing an increase in influenza-like illness (ILI) and have recent culture-confirmed influenza. During week 2, 235 (22.4%) specimens tested by NREVSS laboratories in Texas were positive for influenza. The percentage of visits for influenza-like illness as reported by ILINet providers in Texas was below the regional baseline.
Reports from Health Service Regions
Reports were received from all Health Service Regions (HSRs) for week 2. HSRs 6/5S, 8, and 11 reported the same level of flu activity compared to week 1. All other HSRs reported an increase in flu activity compared to week 1. For a map of Health Service Regions, please visit the following website:
http://www.dshs.state.tx.us/regions/state.shtm
Laboratory Results
During week 2, nine hospital laboratories and public health agencies across Texas reported conducting a total of 1,049 influenza tests (antigen, culture, and PCR) to the National Respiratory and Enteric Virus Surveillance System (NREVSS ) sponsored by the Centers for Disease Control and Prevention (CDC). Of the 952 antigen detection tests that were performed, 166 were positive for influenza A/not subtyped and 41 were positive for influenza B. The positive results were reported from Bell, Bexar, Collin, Harris, Lubbock, Nueces, and Tarrant counties. Eight PCR tests positive for influenza A/not subtyped and three PCR tests positive for influenza B were reported from Bell and Tarrant counties. A total of 86 reports of culture-confirmed influenza were received for the following counties:
| Influenza A/H1 |
Influenza A/H3 |
Influenza A/not subtyped |
Influenza B |
| Brooks County |
(none) |
Bell County (2) |
Bexar County (9) |
| Kleberg County (2) |
|
Bexar County (26) |
Brazos County (2) |
| Medina County |
|
Brazos County |
Dallas County (2) |
| |
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Coryell County |
Harris County (3) |
| |
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Dallas County (15) |
Kendall County |
| |
|
Ellis County |
McLennan County (2) |
| |
|
Harris County (6) |
Tarrant County |
| |
|
Kendall County |
|
| |
|
Madison County (2) |
|
| |
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McLennan County (2) |
|
| |
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Williamson County (5) |
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Additional positive results from point-of-care rapid flu tests were reported by providers throughout the state (see Texas map below).
Antigenic Characterization
CDC has reported antigenic characterization results from 25 influenza isolates [14 influenza A/H1, 0 influenza A/H3, and 11 influenza B viruses] received from the DSHS Laboratory since the beginning of the 2008–09 flu season.
Influenza A/H1 [14]
- Fourteen (100%) of the fourteen viruses were characterized as A/Brisbane/59/2007, the influenza A/H1 component of the 2008–09 influenza vaccine for the Northern Hemisphere.
Influenza A/H3 [0]
- No influenza A/H3 viruses from Texas have been characterized yet this season.
Influenza B (B/Victoria/02/87 and B/Yamagata/16/88 lineages) [11]
Victoria lineage [10] - Two (20%) of the ten viruses were characterized as B/Ohio/01/2005-like viruses.
- Eight (80%) of the ten viruses showed somewhat reduced titers with antisera produced against B/Malaysia/2506/2004 and B/Ohio/01/2005.
Yamagata lineage [1]
- One virus was characterized as B/Florida/4/2006, the influenza B component for the 2008-09 influenza vaccine.
The national antigenic characterization results may be found in the CDC weekly flu report at http://www.cdc.gov/flu/weekly/. The DSHS Laboratory sends a representative sample of influenza viruses to the CDC throughout the flu season.
Influenza–Associated Pediatric Mortality
No influenza-associated pediatric fatalities occurred during week 2.
School Closures and Institutional Outbreaks
No school closures or institutional outbreaks were reported in week 2.
U.S. Outpatient Influenza-like Illness Surveillance Network
Fifty-seven sentinel providers in Texas reported data to the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) (formerly known as the U.S. Influenza Sentinel Provider Surveillance System) on patients with influenza–like illness (ILI) and total patients seen for any reason during week 2. Thirty-five (61%) of these providers saw at least one patient with ILI. Of all patient visits during this week, 3.57% were due to ILI. The ILI baseline for the West South Central Region (Arkansas, Louisiana, Oklahoma, and Texas) of the United States is 4.8% for the 2008-2009 season. The baseline is the mean percentage of patient visits for ILI during non-influenza weeks for the previous three seasons plus two standard deviations.
| Percentage of Visits for Influenza–Like Illness Reported by the US Outpatient Influenza–Like Illness Surveillance Network (ILINet) in Texas as of 1/23/2009 4:12:34 PM |
| Week |
# Reporting |
Age 0-4 |
Age 5-24 |
Age 25-64 |
Age over 64 |
Total ILI |
Total Patients |
% ILI |
| 2008-40 |
77 |
84 |
133 |
127 |
22 |
366 |
20231 |
1.81 |
| 2008-41 |
77 |
114 |
163 |
124 |
19 |
420 |
20000 |
2.10 |
| 2008-42 |
78 |
107 |
156 |
90 |
7 |
360 |
19658 |
1.83 |
| 2008-43 |
78 |
120 |
152 |
106 |
20 |
398 |
19654 |
2.03 |
| 2008-44 |
79 |
136 |
199 |
103 |
26 |
464 |
20653 |
2.25 |
| 2008-45 |
77 |
110 |
111 |
122 |
27 |
370 |
20737 |
1.78 |
| 2008-46 |
72 |
110 |
106 |
103 |
23 |
342 |
19684 |
1.74 |
| 2008-47 |
74 |
137 |
143 |
122 |
19 |
421 |
19722 |
2.13 |
| 2008-48 |
78 |
131 |
132 |
125 |
37 |
425 |
16835 |
2.52 |
| 2008-49 |
74 |
143 |
159 |
153 |
24 |
479 |
19487 |
2.46 |
| 2008-50 |
72 |
133 |
146 |
107 |
28 |
414 |
18587 |
2.23 |
| 2008-51 |
66 |
172 |
177 |
173 |
24 |
546 |
16766 |
3.26 |
| 2008-52 |
73 |
194 |
153 |
154 |
34 |
535 |
13035 |
4.10 |
| 2008-53 |
74 |
167 |
137 |
165 |
46 |
515 |
14831 |
3.47 |
| 2009-01 |
73 |
155 |
175 |
185 |
35 |
550 |
17830 |
3.08 |
| 2009-02 |
57 |
142 |
233 |
194 |
26 |
595 |
16656 |
3.57 |
National Influenza Activity Map
The map showing influenza activity in the United States for MMWR week 2 is displayed below. The current U.S. flu weekly report may be found at: here.
 *This map indicates geographic spread and does not measure the severity of influenza activity.
For more information on flu surveillance activities in the State of Texas, please visit our main surveillance page.
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