IDCU HomeInfectious Diseases A-CD-GH-LM-QR-ST-ZIDCU Health TopicsDisease ReportingRelated Rules & RegulationsImmunization BranchAbout IDCURelated DSHS SitesStaff Contact List
  • Loading...
    Contact Us

    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

Week 17

Loading...
 

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 17

The influenza (flu) activity level for Texas for the week ending May 2, 2009 was “regional.” During week 17, 106 (3.17%) 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 Health Service Regions (HSRs) 1, 2/3, 4/5N, 7, 8, 9/10, and 11 for week 17; however, due to the current swine influenza A/H1N1 investigations, regular reports from many sentinel providers were not received by the HSRs. HSR 9/10 reported a decreased level of flu activity compared to week 16. All other HSRs reported an increased level of 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, nine hospital laboratories and public health agencies across Texas reported conducting a total of 3,344 influenza tests (antigen, culture, and PCR) to the National Respiratory and Enteric Virus Surveillance System (NREVSSnew window) sponsored by the Centers for Disease Control and Prevention (CDC). Of the 2,763 antigen detection tests that were performed, 72 were positive for influenza A/not subtyped and 16 were positive for influenza B. The positive results were reported from Bell, Bexar, Collin, Dallas, Lubbock, and Tarrant counties.

A total of 79 reports of PCR- or culture-confirmed influenza were received from public health laboratories, Scott & White Memorial Hospital in Temple, Texas Children's Hospital in Houston, NREVSS, and the United States Air Force School of Aerospace Medicine (USAFSAM) for the following counties during week 17 (April 26-May 2):

 

Influenza A/H1 (seasonal) Influenza A/H3 Influenza A/not subtyped Influenza B
Bell County Bexar County Bell County (3) Bell County (6)
Bexar County   Bexar County (2) Bexar County (16)
Nueces County   Brazos County (3) Dallas County
Travis County   Dallas County (11) Harris County (3)
Williamson County   Harris County (19) Tarrant County
    Upshur County Travis County
    Williamson County (3) Wichita County (3)

Positive point-of-care rapid tests for influenza were reported by providers throughout the state (see county map below).

Novel Influenza A Virus Infections (information updated 5/15/09)

A total of 96 cases of influenza A/H1 swine confirmed by the CDC have been reported with a known illness onset in week 17 (April 26-May 2) for the following counties (listed by patient county of residence):

 

Influenza A/H1 swine
Bee County
Bexar County (9)
Brazoria County
Comal County
Dallas County (2)
Denton County (2)
Erath County
Fort Bend County (2)
Galveston County
Guadalupe County (3)
Hidalgo County
Johnson County (6)
Matagorda County
Montgomery County (2)
Nolan County
Nueces County (2)
Tarrant County (55)
Taylor County (4)
Wise County

Additional specimens have been identified by PCR testing as positive for unsubtypeable influenza A; these specimens are being forwarded to CDC for further study. This information is subject to change as more reports are received. Thorough case and contact 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/flu/swine/) for more information on the current investigation.

Antigenic Characterization

CDC has reported antigenic characterization results from 50 influenza isolates [20 influenza A/H1, 8 influenza A/H3, and 22 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) [22]

    Victoria lineage [15]
  • Fifteen 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, 21 seasonal influenza A/H1 isolates, 6 influenza A/H3 isolates, and 21 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 21 21 (100%) 0 (0) 21 0 (0)
Influenza A/H3 6 0 (0) 0 (0) 6 6 (100%)
Influenza B 21 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..

Influenz-Associated Pediatric Mortality

No influenza-associated pediatric fatalities in Texas residents were reported during week 17. Texas has reported ten influenza-associated pediatric fatalities during the 2008-09 influenza season.

 

School Closures and Institutional Outbreaks

School closures were reported in HSRs 2/3 (Collin, Dallas, Denton, Johnson, Tarrant, Wichita, and Wise counties); 4/5N (Upshur County); 6 (Harris County), 7 (Grimes and Travis counties), 8 (Comal and Guadalupe counties), and 11 (Hidalgo, Nueces, and Starr counties) during week 17. Not all districts and/or schools within a district were closed in the counties mentioned. The schools in Guadalupe County that closed during week 16 remained closed during week 17. For more information on school closures, please see http://ritter.tea.state.tx.us/swineflu/schclosings.html.

 

U.S. Outpatient Influenza-like Illness Surveillance Network

Fifty-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 17. All of these providers reported seeing patients during week 17, and 47 (82%) providers saw at least one patient with ILI. Of all patient visits during this week, 4.58% 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 Visits for Influenza–Like Illness Reported by the US Outpatient Influenza–Like Illness Surveillance Network (ILINet) in Texas as of 5/8/2009 4:04:49 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 79 120 152 106 20 398 19740 2.02
2008-44 81 136 199 104 26 465 20972 2.23
2008-45 78 110 111 122 27 370 20835 1.78
2008-46 73 110 106 103 23 342 19771 1.73
2008-47 75 137 143 122 19 421 19806 2.13
2008-48 79 131 132 125 37 425 16905 2.51
2008-49 77 143 159 153 24 479 20343 2.35
2008-50 75 133 146 108 28 415 19330 2.15
2008-51 69 172 177 175 24 548 17531 3.13
2008-52 76 194 153 154 34 535 13431 3.98
2008-53 77 176 141 165 46 528 15222 3.47
2009-01 78 162 182 188 38 570 18518 3.08
2009-02 77 178 287 235 41 741 20094 3.69
2009-03 78 174 468 341 43 1026 22951 4.47
2009-04 78 260 679 332 47 1318 24244 5.44
2009-05 73 282 883 465 40 1670 24590 6.79
2009-06 79 301 964 391 59 1715 24162 7.10
2009-07 79 320 814 316 57 1507 25873 5.82
2009-08 73 221 552 283 57 1113 24526 4.54
2009-09 76 194 422 244 71 931 22293 4.18
2009-10 79 221 324 212 77 834 22341 3.73
2009-11 76 167 268 178 58 671 19314 3.47
2009-12 71 109 150 179 18 456 20622 2.21
2009-13 71 114 141 163 16 434 18356 2.36
2009-14 78 158 194 232 51 635 20522 3.09
2009-15 75 92 135 152 23 402 20738 1.94
2009-16 77 100 161 158 27 446 20887 2.14
2009-17 57 192 488 311 42 1033 22553 4.58


ILIPercentageChart

 

ILIDataChart

 

National Influenza Activity Map

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

For more information on flu surveillance activities in the State of Texas, please visit our main surveillance page.





  • Loading...
Last updated July 12, 2012