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    Infectious Disease Control Unit
    Mail Code: 1960
    PO BOX 149347 - Austin, TX 78714-9347
    1100 West 49th Street, Suite T801
    Austin, TX 78714

    Phone: 512 776 7676
    Fax: (512) 776-7616


    E-mail

Surveillance

Influenza
(Flu)
ICD-9 487; ICD-10 J10,11
Related Topics: Protecting Yourself During the Cold and Flu Season, Avian Flu, Vaccine Preventable Diseases, Asthma and SARS

2008 - 2009 Texas Influenza Surveillance Information

Influenza Surveillance Report for MMWR Week 25

The influenza (flu) activity level for Texas for the week ending June 27, 2009 was “local.” During week 25, 9 (4.5%) 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 25. HSR 2/3 reported an increased level of flu activity compared to week 24. HSRs 4/5N, 6/5S, 8, and 11 reported the same level of flu activity compared to week 24. HSRs 1, 7, and 9/10 reported a decreased level of flu activity compared to week 24. For a map of Health Service Regions, please visit the following website: www.dshs.state.tx.us/regions/state.shtm

Laboratory Results

During week 25, five hospital laboratories and public health agencies across Texas reported conducting a total of 201 influenza tests (antigen, culture, and PCR) to the National Respiratory and Enteric Virus Surveillance System (NREVSSwindow_ext) sponsored by the Centers for Disease Control and Prevention (CDC). Of the 160 antigen detection tests that were performed, 8 were positive for influenza A/not subtyped. The positive results were reported from Bexar and Collin counties.

A total of 24 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, the United States Air Force School of Aerospace Medicine (USAFSAM), and NREVSS for the following counties during week 25 (June 21-June 27):

Influenza A/H1 (seasonal) Influenza A/H3 Influenza A/not subtyped Influenza B
McLennan County Bexar County Dallas County (none)
  Comal County Harris County (16)  
    Maverick County (2)  
    Morris County  
    Zavala County  

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 (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 seasonal influenza isolates [20 influenza A/H1, 8 influenza A/H3, and 23 influenza B viruses] and 2 novel influenza A H1N1 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.
Novel influenza A/H1 [2]
  • Both viruses were characterized as A/California/07/2009-like (H1N1), the reference virus selected by WHO as a candidate for the novel influenza A H1N1 vaccine.

Antiviral Resistance

Since September 28, 2008, 22 seasonal influenza A/H1 isolates, 7 influenza A/H3 isolates, 22 influenza B isolates, and 1 novel influenza A H1N1 isolate from the DSHS laboratory have been tested by CDC for antiviral resistance.
Antiviral Resistance
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 7 0 (0) 0 (0) 7 7 (100%)
Influenza B 22 0 (0) 0 (0) N/A* N/A*
Influenza A/H1 (novel) 1 0 (0) 0 (0) 1 1 (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

No influenza-associated pediatric fatalities were reported during week 25. 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 25. An outbreak of novel influenza A H1N1 was reported in a summer camp in Dallas County during week 25. 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

Fifty-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 25. Of the 50 providers who reported seeing patients during week 25, 25 (50%) providers saw at least one patient with ILI. Of all patient visits during this week, 0.87% 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 7/9/2009 6:47:38 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 61 109 202 97 23 431 40506 1.06
2009-23 53 79 103 29 9 220 9735 2.26
2009-24 49 67 132 86 5 290 37065 0.78
2009-25 51 72 117 83 15 287 32849 0.87


ILIPercentageChart1

National Influenza Activity Map

The current U.S. flu weekly report may be found at http://www.cdc.gov/flu/weekly/fluactivity.htm.
USMapweekly2

*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


Last updated July 12, 2012