2008 - 2009 Texas Influenza Surveillance Information
Influenza Surveillance Report for MMWR Week 3
The influenza (flu) activity level for Texas for the week ending January 24, 2009 was “widespread.” (Texas had previously reported “regional” activity to CDC for week 3, but this was amended to “widespread” based on new information.) Widespread activity indicates that at least half of the regions in the state are experiencing an increase in influenza-like illness (ILI) and have recent culture-confirmed influenza. During week 3, 333 (25.4%) 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 3. HSRs 8 and 11 reported the same level of flu activity compared to week 2. All other HSRs reported an increase in flu activity compared to week 2. 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 3, eight hospital laboratories and public health agencies across Texas reported conducting a total of 1,312 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 1,289 antigen detection tests that were performed, 269 were positive for influenza A/not subtyped and 55 were positive for influenza B. The positive results were reported from Bexar, Harris, Lubbock, Nueces, and Tarrant counties. Twenty-seven PCR tests positive for influenza A/H1, one PCR test positive for influenza A/H3, eight PCR tests positive for influenza A/not subtyped, and sixteen PCR tests positive for influenza B were reported from Bell, Bexar, Harris, Tarrant, and Williamson counties. [There may be some overlap in the PCR and culture positive results described in this report (i.e., some of the PCR results may be from some of the same patients as the culture results).] A total of 245 reports of culture-confirmed influenza were received from public health laboratories in Austin, Dallas, and Houston; Scott & White Memorial Hospital in Temple; Texas Children's Hospital in Houston; the United States Air Force School of Aerospace Medicine; and other sources for the following counties:
| Influenza A/H1 |
Influenza A/H3 |
Influenza A/not subtyped |
Influenza B |
| Anderson County |
Dallas County (4) |
Bell County (2) |
Angelina County (7) |
| Angelina County (10) |
Taylor County |
Bexar County (31) |
Bell County |
| Bandera County |
|
Brazos County (2) |
Bexar County (7) |
| Bexar County (18) |
|
Burleson County |
Brazos County (8) |
| Dallas County (2) |
|
Coryell County |
Dallas County (9) |
| El Paso County |
|
Dallas County (50) |
El Paso County |
| Gregg County |
|
Harris County (30) |
Harris County (28) |
| Jasper County (2) |
|
McLennan County (2) |
Limestone County (2) |
| Kleberg County |
|
Williamson County (3) |
McLennan County (3) |
| Medina County (2) |
|
|
Smith County |
| Montgomery County |
|
|
Travis County |
| Smith County |
|
|
Wichita County |
| Travis County (4) |
|
|
|
| Val Verde County |
|
|
|
| Wichita County (3) |
|
|
|
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 3. Texas has reported one influenza-associated pediatric fatality during the 2008-09 influenza season.
School Closures and Institutional Outbreaks
Institutional outbreaks due to influenza and influenza-like illnesses were reported in multiple schools during week 3. One school in Dallas County reported multiple tests positive for influenza; the majority of these tests were positive for influenza A/H3. A school in Hood County reported increased absenteeism due to influenza-like illness. One Henderson County school reported several rapid tests positive for influenza B, including some in persons who had been vaccinated for influenza during the current season. A school in Caldwell County reported several students absent due to influenza-like illness. None of the schools closed due to the illnesses.
U.S. Outpatient Influenza-like Illness Surveillance Network
Fifty-nine 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 3. Forty (68%) of these providers saw at least one patient with ILI. Of all patient visits during this week, 4.31% 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 1/30/2009 2:41:29 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 |
75 |
156 |
177 |
188 |
38 |
559 |
18091 |
3.09 |
| 2009-02 |
71 |
172 |
279 |
225 |
39 |
715 |
19056 |
3.75 |
| 2009-03 |
59 |
104 |
388 |
300 |
25 |
817 |
18973 |
4.31 |
National Influenza Activity Map
The map showing influenza activity in the United States for MMWR week 3 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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