2008 - 2009 Texas Influenza Surveillance Information
Influenza Surveillance Report for MMWR Week 23
The influenza (flu) activity level for Texas for the week ending June 13, 2009 was “local.” During week 23, 28 (8.7%) 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 23. HSRs 2/3 and 4/5N reported an increased level of flu activity compared to week 22. HSRs 6/5S, 8, and 9/10 reported the same level of flu activity compared to week 22. All other HSRs reported a decreased level of flu activity compared to week 22. 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 23, eight hospital laboratories and public health agencies across Texas reported conducting a total of 323 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 290 antigen detection tests that were performed, 25 were positive for influenza A/not subtyped and one was positive for influenza B. The positive results were reported from Bexar, Collin, Dallas, Harris, Lubbock, Nueces, and Tarrant counties. A total of 53 reports of PCR- or culture-confirmed seasonal influenza were received from public health laboratories, Texas Children's Hospital in Houston, and NREVSS for the following counties during week 23 (June 7-June 13):
Influenza A/H1 (seasonal) |
Influenza A/H3 |
Influenza A/not subtyped |
Influenza B |
(none) |
(none) |
Dallas County (2) |
(none) |
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Dimmit County (2) |
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Gillespie County |
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Harris County (45) |
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Kendall County |
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Victoria County |
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Webb County |
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Positive point-of-care rapid tests for influenza were reported by providers throughout the state (see county map below).
Novel Influenza A Virus Infections
Case investigations are ongoing, and the number of confirmed cases changes frequently. Please see the DSHS website (http://www.dshs.state.tx.us/swineflu/default.shtm) and the CDC website (http://www.cdc.gov/h1n1flu/) for more information on the current investigation.
Antigenic Characterization
CDC has reported antigenic characterization results from 51 influenza isolates [20 influenza A/H1, 8 influenza A/H3, and 23 influenza B viruses] received from the DSHS Laboratory since the beginning of the 2008–09 flu season. Influenza A/H1 [20]
- All 20 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 [8]
- All 8 viruses were characterized as A/Brisbane/10/2007, the influenza A/H3 component of the 2008-09 influenza vaccine for the Northern Hemisphere.
Influenza B (B/Victoria/02/87 and B/Yamagata/16/88 lineages) [23]
Victoria lineage [16] - Sixteen of the influenza B viruses were characterized as belonging to the B/Victoria lineage.
Yamagata lineage [7] - Seven viruses were characterized as B/Florida/4/2006, the influenza B component for the 2008-09 influenza vaccine for the Northern Hemisphere.
Antiviral Resistance
Since September 28, 2008, 22 seasonal influenza A/H1 isolates, 7 influenza A/H3 isolates, and 22 influenza B isolates from the DSHS laboratory have been tested by CDC for antiviral resistance.
|
Isolates Tested (n) |
Resistant Viruses, Number (%)
|
Isolates Tested (n) |
Resistant Viruses, Number (%)
|
Oseltamivir |
Zanamivir |
Adamantanes |
Influenza A/H1 |
22 |
22 (100%) |
0 (0) |
22 |
0 (0) |
Influenza A/H3 |
7 |
0 (0) |
0 (0) |
7 |
7 (100%) |
Influenza B |
22 |
0 (0) |
0 (0) |
N/A* |
N/A* |
*Adamantanes are not effective against influenza B viruses. CDC has issued interim recommendations for use of antiviral medications in the 2008-09 influenza season. Those recommendations are available at: http://www.cdc.gov/flu/professionals/antivirals/index.htm..
Influenza–Associated Pediatric Mortality
No influenza-associated pediatric fatalities were reported during week 23. Texas has reported thirteen influenza-associated pediatric fatalities during the 2008-09 influenza season. School Closures and Institutional Outbreaks
No school closures or institutional outbreaks were reported for week 23. HSR 4/5N reported two camps with ILI and at least one confirmed case of novel influenza A H1N1 in each camp during week 23. CDC has issued interim guidance for cases of novel influenza A H1N1 in summer camps. This guidance is available at http://www.cdc.gov/h1n1flu/camp.htm. U.S. Outpatient Influenza-like Illness Surveillance Network
Forty-one 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 23. Of the 40 providers who reported seeing patients during week 23, 17 (43%) providers saw at least one patient with ILI. Of all patient visits during this week, 1.97% were due to ILI. The ILI baseline for HHS Region 6 (Arkansas, Louisiana, New Mexico, Oklahoma, and Texas) of the United States is 4.6% 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 6/19/2009 12:23:01 PM |
Week |
# Reporting |
Age 0-4 |
Age 5-24 |
Age 25-64 |
Age over 64 |
Total ILI |
Total Patients |
% ILI |
2008-40 |
78 |
84 |
133 |
127 |
22 |
366 |
20333 |
1.80 |
2008-41 |
78 |
114 |
163 |
124 |
19 |
420 |
20105 |
2.09 |
2008-42 |
79 |
107 |
156 |
90 |
7 |
360 |
19746 |
1.82 |
2008-43 |
80 |
120 |
152 |
106 |
20 |
398 |
19857 |
2.00 |
2008-44 |
82 |
136 |
199 |
104 |
26 |
465 |
20972 |
2.22 |
2008-45 |
79 |
110 |
111 |
122 |
27 |
370 |
20959 |
1.77 |
2008-46 |
74 |
110 |
107 |
103 |
23 |
343 |
19890 |
1.72 |
2008-47 |
76 |
137 |
143 |
122 |
19 |
421 |
19907 |
2.11 |
2008-48 |
80 |
132 |
132 |
125 |
37 |
426 |
17012 |
2.50 |
2008-49 |
78 |
143 |
159 |
153 |
24 |
479 |
20446 |
2.34 |
2008-50 |
76 |
133 |
146 |
108 |
28 |
415 |
19450 |
2.13 |
2008-51 |
70 |
172 |
177 |
175 |
24 |
548 |
17663 |
3.10 |
2008-52 |
77 |
194 |
153 |
154 |
34 |
535 |
13509 |
3.96 |
2008-53 |
78 |
176 |
141 |
165 |
46 |
528 |
15329 |
3.44 |
2009-01 |
79 |
162 |
182 |
188 |
38 |
570 |
18646 |
3.06 |
2009-02 |
78 |
178 |
287 |
235 |
41 |
741 |
20222 |
3.66 |
2009-03 |
79 |
174 |
468 |
341 |
43 |
1026 |
23058 |
4.45 |
2009-04 |
79 |
260 |
679 |
333 |
47 |
1319 |
24350 |
5.42 |
2009-05 |
74 |
282 |
884 |
467 |
40 |
1673 |
24734 |
6.76 |
2009-06 |
80 |
301 |
965 |
392 |
59 |
1717 |
24320 |
7.06 |
2009-07 |
80 |
320 |
816 |
316 |
57 |
1509 |
26024 |
5.80 |
2009-08 |
74 |
221 |
552 |
283 |
57 |
1113 |
24664 |
4.51 |
2009-09 |
77 |
194 |
423 |
245 |
71 |
933 |
22428 |
4.16 |
2009-10 |
80 |
221 |
325 |
212 |
77 |
835 |
22635 |
3.69 |
2009-11 |
77 |
167 |
269 |
178 |
58 |
672 |
19656 |
3.42 |
2009-12 |
72 |
109 |
150 |
179 |
18 |
456 |
20910 |
2.18 |
2009-13 |
73 |
114 |
143 |
163 |
16 |
436 |
18660 |
2.34 |
2009-14 |
80 |
158 |
197 |
234 |
51 |
640 |
20843 |
3.07 |
2009-15 |
77 |
92 |
136 |
156 |
23 |
407 |
21124 |
1.93 |
2009-16 |
85 |
131 |
197 |
163 |
28 |
519 |
21938 |
2.37 |
2009-17 |
77 |
260 |
570 |
348 |
44 |
1222 |
25406 |
4.81 |
2009-18 |
72 |
200 |
361 |
185 |
31 |
777 |
22503 |
3.45 |
2009-19 |
65 |
125 |
253 |
183 |
24 |
585 |
19066 |
3.07 |
2009-20 |
63 |
122 |
255 |
134 |
7 |
518 |
19150 |
2.70 |
2009-21 |
64 |
115 |
238 |
115 |
31 |
499 |
39616 |
1.26 |
2009-22 |
58 |
105 |
182 |
92 |
23 |
402 |
39494 |
1.02 |
2009-23 |
41 |
49 |
70 |
13 |
5 |
137 |
6957 |
1.97 |
National Influenza Activity Map
The current U.S. flu weekly report may be found at http://www.cdc.gov/flu/weekly/fluactivity.htm. *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.
*Influenza activity level corresponds to current MMWR week only and does not reflect previous weeks' activity. **Positives are reported according to specimen collection date or date received in the lab, if the former is unknown
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