2008 - 2009 Texas Influenza Surveillance Information
Influenza Surveillance Report for MMWR Week 53
The influenza (flu) activity level for Texas for the week ending January 3, 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 53, seventeen (4.4%) 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. Flu is occurring in the state at a low level.
Reports from Health Service Regions
Reports were received from all Health Service Regions (HSRs) for week 53. HSRs 2/3, 7, 8, and 11 reported an increase in flu activity compared to week 52. HSR 1 reported a decrease in flu activity compared to week 52. All other HSRs reported the same level of flu activity compared to week 52. 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 53, eight hospital laboratories and public health agencies across Texas reported conducting a total of 386 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 338 antigen detection tests that were performed, 10 were positive for influenza A/not subtyped and 3 were positive for influenza B. The positive results were reported from Atascosa, Bell, Bexar, and Collin counties. One positive PCR test for influenza B was reported. A total of 11 reports of culture-confirmed influenza were received for the following counties:
| Influenza A/H1 |
Influenza A/H3 |
Influenza A/not subtyped |
Influenza B |
| Dallas County |
(none) |
Brazos County |
Harris County |
| Starr County |
|
Dallas County |
Starr County (2) |
| |
|
|
Tarrant County |
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
No influenza–associated pediatric fatalities were reported during week 53. School Closures and Institutional Outbreaks
No school closures or institutional outbreaks were reported during week 53. U.S. Outpatient Influenza-like Illness Surveillance Network
Fifty 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 53. Of the 44 providers who saw patients during week 53, twenty-three (52%) saw at least one patient with ILI. Of all patient visits during this week, 3.31% 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 Influenza–Like Illness (ILI) Reported by Sentinel Providers in Texas as of 1/9/2009 1:38:15 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 |
72 |
136 |
154 |
147 |
24 |
461 |
19159 |
2.41 |
| 2008-50 |
70 |
125 |
143 |
105 |
28 |
401 |
18240 |
2.20 |
| 2008-51 |
61 |
155 |
163 |
168 |
24 |
510 |
16072 |
3.17 |
| 2008-52 |
63 |
150 |
139 |
137 |
13 |
439 |
12086 |
3.63 |
| 2008-53 |
50 |
116 |
109 |
132 |
31 |
388 |
11737 |
3.31 |
National Influenza Activity Map
The map showing influenza activity in the United States for MMWR week 53 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.
|