2007 - 2008 Texas Influenza Surveillance Information
Influenza Surveillance Report for MMWR Week 17
The influenza (flu) activity level for Texas for the week ending April 26, 2008 was “sporadic.” Sporadic activity indicates that isolated reports of laboratory-confirmed influenza along with influenza–like illness (ILI) have been reported. During week 17, nine (6.7%) specimens tested by NREVSS laboratories in Texas were positive for influenza. The percentage of visits due to influenza–like illness (ILI) as reported by SPSN providers in Texas was below the regional baseline. Flu activity in Texas in week 17 continued to decrease in most regions.
Reports from Health Service Regions
Reports were received from all Health Service Regions (HSRs) for week 17. HSR 1 reported an increase in flu activity compared to week 16. All other regions reported a decrease in overall flu activity compared to week 16. 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 17, six hospital laboratories and public health agencies across Texas reported conducting a total of 135 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 108 antigen detection tests performed, seven were positive for influenza A/not subtyped and one was positive for influenza B. These results were reported from Bexar, Collin, and Tarrant counties. One PCR test positive for influenza B was reported from Tarrant County. Texas Children’s Hospital in Harris County reported one culture positive for influenza B. Additional positive results from point-of-care rapid flu tests were reported by providers throughout the state (see Texas map).
Antigenic Characterization
CDC has reported antigenic characterization results from 35 influenza isolates [8 influenza A/H1, 24 influenza A/H3, and 3 influenza B viruses] received from the DSHS Laboratory since the beginning of the 2007–08 flu season.
Influenza A/H1 [8]
- Eight (100%) of the eight viruses were characterized as A/Solomon Islands/3/2006, the influenza A/H1 component of the 2007–08 influenza vaccine for the Northern Hemisphere.
Influenza A/H3 [24]
- Two (8%) of the 24 viruses were characterized as A/Wisconsin/67/2005–like, the influenza A/H3 component of the 2007–08 influenza vaccine for the Northern Hemisphere.
- Twenty–one (88%) of the 24 viruses were characterized as A/Brisbane/10/2007–like. A/Brisbane/10/2007 is a recent antigenic variant which evolved from A/Wisconsin/67/2005–like.
- One (4%) of the 24 viruses showed somewhat reduced titers with antisera produced against A/Wisconsin/67/2005 and A/Brisbane/10/2007.
Influenza B (B/Victoria/02/87 and B/Yamagata/16/88 lineages) [4]
Victoria lineage [0] - The influenza B component for the 2007–08 influenza vaccine is a B/Malaysia/2506/2004–like virus, belonging to the B/Victoria lineage.
Yamagata lineage [4]
- Four (100%) of the four viruses were identified as belonging to the B/Yamagata lineage of viruses.
These results are very similar to national antigenic characterization results. The national 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 17. As of week 17, Texas has reported seven influenza–associated pediatric deaths in the 2007–08 influenza season.
School Closures and Institutional Outbreaks
No school closures or institutional outbreaks were reported during week 17.
Sentinel Provider Surveillance Network
Sixty–three sentinel providers in Texas reported data to the U.S. Influenza Sentinel Provider Surveillance System (SPSN) on patients with influenza–like illness (ILI) and total patients seen for any reason during week 17; of the 62 providers who reported seeing patients, 20 (32.3%) providers saw at least one patient with ILI. Of all patient visits during this week, 2.14% were due to ILI. The ILI baseline for the West South Central Region (Arkansas, Louisiana, Oklahoma, and Texas) of the United States is 4.3% for the 2007–2008 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 ((5/5/2008 5:49:37 PM) |
Week |
# Reporting |
Age 0-4 |
Age 5-24 |
Age 25-64 |
Age over 64 |
Total ILI |
Total Patients |
% ILI |
2007-40 |
84 |
256 |
163 |
151 |
49 |
619 |
21410 |
2.89 |
2007-41 |
88 |
264 |
255 |
207 |
58 |
784 |
25255 |
3.10 |
2007-42 |
86 |
274 |
270 |
261 |
50 |
855 |
25776 |
3.32 |
2007-43 |
85 |
368 |
290 |
208 |
47 |
913 |
26428 |
3.45 |
2007-44 |
95 |
391 |
276 |
206 |
55 |
928 |
28213 |
3.29 |
2007-45 |
87 |
411 |
314 |
243 |
39 |
1007 |
25665 |
3.92 |
2007-46 |
79 |
442 |
306 |
215 |
65 |
1028 |
24713 |
4.16 |
2007-47 |
91 |
478 |
317 |
272 |
73 |
1140 |
22748 |
5.01 |
2007-48 |
84 |
506 |
298 |
299 |
74 |
1177 |
26193 |
4.49 |
2007-49 |
84 |
232 |
290 |
162 |
16 |
700 |
20713 |
3.38 |
2007-50 |
80 |
256 |
265 |
128 |
16 |
665 |
18711 |
3.55 |
2007-51 |
68 |
169 |
197 |
186 |
26 |
578 |
15597 |
3.71 |
2007-52 |
77 |
176 |
201 |
191 |
22 |
590 |
12436 |
4.74 |
2008-01 |
90 |
217 |
302 |
332 |
29 |
880 |
16520 |
5.33 |
2008-02 |
97 |
373 |
500 |
630 |
117 |
1620 |
25891 |
6.26 |
2008-03 |
81 |
289 |
518 |
370 |
36 |
1213 |
21940 |
5.53 |
2008-04 |
87 |
369 |
886 |
650 |
54 |
1959 |
23306 |
8.41 |
2008-05 |
96 |
601 |
1208 |
954 |
158 |
2921 |
29106 |
10.04 |
2008-06 |
96 |
557 |
1128 |
951 |
112 |
2748 |
28337 |
9.37 |
2008-07 |
100 |
529 |
1037 |
808 |
124 |
2498 |
27849 |
8.97 |
2008-08 |
99 |
423 |
789 |
769 |
92 |
2073 |
26573 |
7.80 |
2008-09 |
91 |
421 |
576 |
690 |
83 |
1770 |
26637 |
6.64 |
2008-10 |
91 |
344 |
466 |
494 |
80 |
1384 |
24965 |
5.54 |
2008-11 |
82 |
259 |
366 |
385 |
39 |
1049 |
18473 |
5.68 |
2008-12 |
82 |
157 |
169 |
113 |
26 |
465 |
14055 |
3.31 |
2008-13 |
88 |
186 |
244 |
292 |
24 |
746 |
19842 |
3.76 |
2008-14 |
92 |
307 |
266 |
325 |
78 |
976 |
24159 |
4.04 |
2008-15 |
83 |
263 |
224 |
255 |
90 |
832 |
25408 |
3.27 |
2008-16 |
82 |
217 |
241 |
290 |
52 |
800 |
25141 |
3.18 |
2008-17 |
63 |
75 |
105 |
130 |
12 |
322 |
15037 |
2.14 |
The map showing influenza activity in the United States for MMWR week 17 is displayed below. The current U.S. flu weekly report may be found here.
For more information on flu surveillance activities in the State of Texas, please visit our main surveillance page.
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Texas Department of State Health Services - Infectious Disease Control Unit
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