2008 - 2009 Texas Influenza Surveillance Information
Influenza Surveillance Report for MMWR Week 35
The influenza (flu) activity level for Texas for the week ending September 5, 2009 was “regional.” For definitions of flu activity levels please see http://www.cdc.gov/flu/weekly/fluactivity.htm. During week 35, 115 (9.6%) 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 increased during week 35 but still remained below the regional baseline.
Reports from Health Service Regions
Reports were received from all Health Service Regions (HSRs) for week 35. HSRs 1, 2/3, 4/5N, 6/5S, 7, and 11 reported an increased level of flu activity compared to week 34. HSRs 8 and 9/10 reported the same level of flu activity compared to week 34. For a map of Health Service Regions please visit the following website: www.dshs.state.tx.us/regions/state.shtm Laboratory Results
During week 35, four hospital laboratories and public health agencies across Texas reported conducting a total of 1,196 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 469 antigen detection tests that were performed, 86 were positive for influenza A/not subtyped. The positive results were reported from Anderson, Bell, and Bexar counties. A total of 48 reports of PCR- or culture-confirmed seasonal or unsubtyped influenza were received from public health laboratories, Scott & White Memorial Hospital in Temple, Texas Children's Hospital in Houston, and other sources for the following counties during week 35 (August 30-September 5):
Influenza A/H1 (seasonal) |
Influenza A/H3 |
Influenza A/not subtyped |
Influenza B |
(none) |
(none) |
Bell County (14) |
(none) |
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Bexar County |
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Brazos County (7) |
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Burleson County |
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Harris County (15) |
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Madison County |
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McLennan County (4) |
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Milam County |
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Navarro County |
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Williamson County (3) |
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Positive point-of-care rapid tests for influenza were reported by sentinel providers throughout the state (see county map below).
Novel Influenza A Virus Infections
Please see the Texas Department of State Health Services (DSHS) novel influenza website (http://www.texasflu.org) and the CDC website (http://www.cdc.gov/h1n1flu/) for more information.
Antigenic Characterization
CDC has reported antigenic characterization results from 51 seasonal influenza isolates [20 influenza A/H1, 8 influenza A/H3, and 23 influenza B viruses] and 4 novel influenza A H1N1 viruses received from the DSHS Laboratory since the beginning of the 2008–09 flu season. Other laboratories in Texas submit influenza isolates to CDC for testing, but those results were not available for this report. 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.
Novel influenza A/H1 [4]
- All 4 viruses were characterized as A/California/07/2009-like (H1N1), the reference virus selected by the World Health Organization (WHO) as a candidate for the novel influenza A H1N1 vaccine.
Antiviral Resistance
Since September 28, 2008, 22 seasonal influenza A/H1N1 isolates, 8 influenza A/H3N2 isolates, 23 influenza B isolates, and 5 novel influenza A/H1N1 isolates from the DSHS laboratory have been tested by CDC for antiviral resistance. Other laboratories in Texas submit influenza isolates to CDC for testing, but those results were not available for this report.
Flu Types/Subtypes |
Isolates Tested (n) |
Resistant Viruses, Number (%)
|
Isolates Tested (n) |
Resistant Viruses, Number (%)
|
Oseltamivir |
Zanamivir |
Adamantanes |
Influenza A/H1 (seasonal) |
22 |
22 (100%) |
0 (0) |
22 |
0 (0) |
Influenza A/H3 |
8 |
0 (0) |
0 (0) |
7 |
7 (100%) |
Influenza B |
23 |
0 (0) |
0 (0) |
N/A* |
N/A* |
Influenza A/H1 (novel) |
5 |
2 (40%) |
0 (0) |
5 |
5 (100%) |
*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
One influenza-associated pediatric fatality occurred during week 35 in a 13-year-old resident of Health Service Region 9/10 with significant underlying medical conditions. A specimen obtained from the child was positive for novel influenza A/H1N1 by PCR. Texas has reported 15 influenza-associated pediatric fatalities during the 2008-09 influenza season. School Closures and Institutional Outbreaks
An outbreak of novel influenza A/H1N1 was reported in a school in Henderson County during week 35. Dallas County also reported an outbreak of influenza A (not subtyped) at a college campus. DSHS has issued guidance for cases of ILI and novel influenza A H1N1 in summer camps, schools, and congregate facilities. Please see http://www.texasflu.org for more information. U.S. Outpatient Influenza-like Illness Surveillance Network
Thirty-seven 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 35. Of these 37 providers, 23 (62%) saw at least one patient with ILI. Of all patient visits during this week, 3.23% 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 9/14/2009 12:36:31 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 |
79 |
317 |
803 |
316 |
57 |
1493 |
25821 |
5.78 |
2009-08 |
74 |
221 |
552 |
283 |
57 |
1113 |
24664 |
4.51 |
2009-09 |
77 |
194 |
423 |
245 |
71 |
933 |
22428 |
4.16 |
2009-10 |
81 |
222 |
340 |
228 |
77 |
867 |
44281 |
1.96 |
2009-11 |
77 |
167 |
269 |
178 |
58 |
672 |
19656 |
3.42 |
2009-12 |
72 |
109 |
150 |
179 |
18 |
456 |
20910 |
2.18 |
2009-13 |
74 |
115 |
143 |
163 |
16 |
437 |
18760 |
2.33 |
2009-14 |
81 |
158 |
199 |
234 |
51 |
642 |
20963 |
3.06 |
2009-15 |
78 |
92 |
138 |
156 |
23 |
400 |
21254 |
1.92 |
2009-16 |
87 |
133 |
200 |
163 |
28 |
524 |
22058 |
2.38 |
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 |
221 |
111 |
31 |
478 |
17728 |
2.70 |
2009-22 |
61 |
108 |
188 |
88 |
14 |
398 |
18573 |
2.14 |
2009-23 |
55 |
79 |
103 |
29 |
9 |
220 |
10111 |
2.18 |
2009-24 |
53 |
65 |
119 |
79 |
4 |
267 |
16773 |
1.59 |
2009-25 |
59 |
72 |
114 |
79 |
15 |
280 |
16624 |
1.68 |
2009-26 |
59 |
68 |
105 |
75 |
13 |
261 |
15326 |
1.70 |
2009-27 |
58 |
72 |
90 |
72 |
15 |
249 |
16643 |
1.50 |
2009-28 |
61 |
44 |
102 |
78 |
15 |
238 |
17296 |
1.38 |
2009-29 |
59 |
67 |
101 |
73 |
14 |
255 |
16844 |
1.51 |
2009-30 |
54 |
25 |
41 |
23 |
11 |
100 |
9861 |
1.01 |
2009-31 |
57 |
55 |
91 |
83 |
9 |
238 |
17480 |
1.36 |
2009-32 |
53 |
54 |
108 |
76 |
9 |
247 |
17183 |
1.44 |
2009-33 |
50 |
46 |
107 |
124 |
13 |
290 |
18628 |
1.56 |
2009-34 |
49 |
73 |
266 |
94 |
3 |
436 |
18826 |
2.32 |
2009-35 |
37 |
110 |
408 |
83 |
4 |
605 |
18759 |
3.23 |
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.
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