2008 - 2009 Texas Influenza Surveillance Information
Influenza Surveillance Report for MMWR Week 1
The influenza (flu) activity level for Texas for the week ending January 10, 2009 was “local.” Local activity indicates that a single region of the state is experiencing an increase in influenza-like illness (ILI) and has recent laboratory-confirmed influenza. During week 1, 99 (9.5%) 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 1. HSRs 9/10 and 11 reported the same level of flu activity compared to week 53. All other HSRs reported an increase in flu activity compared to week 53. 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 1, ten hospital laboratories and public health agencies across Texas reported conducting a total of 1,037 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 932 antigen detection tests that were performed, 80 were positive for influenza A/not subtyped and 15 were positive for influenza B. The positive results were reported from Bexar, Dallas, Harris, Hunt, Lubbock, and Tarrant counties. One positive PCR test for influenza A/not subtyped was reported in both Maverick and Medina counties. A total of 30 reports of culture-confirmed influenza were received for the following counties:
| Influenza A/H1 |
Influenza A/H3 |
Influenza A/not subtyped |
Influenza B |
| Brazos County |
(none) |
Dallas County (6) |
Brazos County |
| Brooks County (2) |
|
Harris County (7) |
Harris County (4) |
| Cameron County (3) |
|
|
Tarrant County |
| Dallas County (2) |
|
|
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| McLennan County (2) |
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|
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| Medina County |
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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 21 influenza isolates [11 influenza A/H1, 0 influenza A/H3, and 10 influenza B viruses] received from the DSHS Laboratory since the beginning of the 2008–09 flu season.
Influenza A/H1 [11]
- Eleven (100%) of the eleven 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) [10]
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 [0]
- The influenza B component for the 2008-09 influenza vaccine is a B/Florida/4/2006-like virus, belonging to the B/Yamagata lineage.
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
One influenza–associated pediatric fatality occurred during MMWR week 1. The child was a 16–year–old resident of Health Service Region 8 who had a significant underlying medical condition. The child was not vaccinated for influenza for the current season. The patient was culture positive for influenza B. This is the first influenza–associated pediatric fatality reported in Texas in the 2008–09 influenza season.
School Closures and Institutional Outbreaks
No school closures or institutional outbreaks were reported during week 1.
U.S. Outpatient Influenza-like Illness Surveillance Network
Sixty-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 1. Of the 65 providers who saw patients during week 1, 35 (54%) saw at least one patient with ILI. Of all patient visits during this week, 3.15% 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 1/16/2009 4:04:46 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 |
1.80 |
| 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 |
72 |
194 |
153 |
154 |
34 |
535 |
12960 |
4.13 |
| 2008-53 |
73 |
167 |
137 |
165 |
46 |
515 |
14804 |
3.48 |
| 2009-01 |
67 |
155 |
174 |
177 |
35 |
541 |
17172 |
3.15 |
National Influenza Activity Map
The map showing influenza activity in the United States for MMWR week 1 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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