2010-2011 DSHS Flu Report Week 14

2010 - 2011 Texas Influenza Surveillance Information

During week 14 in Texas:

• The influenza (flu) activity level (geographic spread of influenza) for Texas was “sporadic” and the ILINet Activity Level Indicator (intensity of influenza-like illness) was “minimal”.  For more information please see http://www.cdc.gov/flu/weekly/fluactivity.htm and the national FluView weekly report at http://www.cdc.gov/flu/weekly/. 
• Twenty-two (4.4%) specimens tested by NREVSS laboratories in Texas were positive for influenza. Two specimens were positive for influenza A (not subtyped) by viral culture or PCR testing; the remaining positive results were obtained by antigen detection test.
• The percentage of visits for influenza-like illness as reported by ILINet providers in Texas was below the state and HHS regional baselines.
• No influenza-associated pediatric deaths were reported.
• No institutional outbreaks or school closures were reported.

Reports from Health Service Regions

Reports were received from all Health Service Regions (HSRs) for week 14. HSR 8 reported the same level of flu activity compared to week 13. All other HSRs reported a decreased level of flu activity compared to week 13. For a map of Health Service Regions please visit the following website: http://www.dshs.state.tx.us/regions/state.shtm.

Laboratory Results

Influenza

During week 14, seven hospital laboratories and public health agencies across Texas reported conducting a total of 495 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). Sixty-three percent of the influenza tests reported to NREVSS were antigen detection tests; these tests cannot identify the subtype of influenza detected. The results from Texas participants in NREVSS are summarized in the table below.

Additional influenza test results (rapid tests, culture, PCR) were reported from providers and public health departments throughout the state (see county map below). 

Other Respiratory Viruses

The NREVSS system collects information on a variety of respiratory viruses in addition to influenza including parainfluenza, respiratory syncytial virus (RSV), rhinovirus, human metapneumovirus (HMPV), and respiratory adenovirus. The results from week 14 are summarized below.

Antigenic Characterization

Since October 3, 2010, CDC has reported antigenic characterization results from 11 influenza A (H1N1) viruses, 30 influenza A (H3N2) viruses, and 14 influenza B viruses received from the Texas Department of State Health Services (DSHS) Laboratory.

• Influenza A (H1N1) [11]
  Eleven viruses were related to A/California/07/2009-like (H1N1), the influenza A (H1N1) component of the 2010-2011 influenza vaccine for the Northern Hemisphere.
• Influenza A (H3N2) [30]
  Thirty viruses were related to A/Perth/16/2009-like (H3N2), the influenza A (H3N2) component of the 2010-2011 influenza vaccine for the Northern Hemisphere.
• Influenza B [14]
  • Victoria lineage [14]
    Fourteen influenza B viruses were related to B/Brisbane/60/2008-like, the influenza B component of the 2010-2011 influenza vaccine for the Northern Hemisphere.
  • Yamagata lineage [0]
    No influenza B viruses of the Yamagata lineage have been characterized since 2009.

The national antigenic characterization and antiviral resistance testing results may be found in the final CDC weekly flu report at www.cdc.gov/flu/weekly/. The DSHS Laboratory sends a representative sample of influenza viruses to the CDC throughout the flu season. 

Antiviral Resistance

No Texas influenza isolates tested so far in the 2010-2011 influenza season have demonstrated resistance to oseltamivir or zanamivir. Resistance to the adamantanes has been detected in most of the 2009 influenza A (H1N1) and influenza A (H3N2) isolates tested over the last two influenza seasons. For more information on antiviral medications please see http://www.cdc.gov/flu/professionals/antivirals/index.htm.

Influenza–Associated Pediatric Mortality

No influenza-associated pediatric deaths were reported during week 14.  Twelve influenza-associated pediatric fatalities have been reported in Texas since the beginning of the 2010-2011 influenza season. Eleven deaths have been reported during calendar year 2011. Please see the table below for more information

Cases of influenza-associated pediatric mortality (children <18 years of age) are reportable year-round and by law in Texas. Please see http://www.dshs.state.tx.us/idcu/investigation/conditions/ for more information.  

Influenza-Associated Deaths in Pregnant and Postpartum Women

No influenza-associated deaths were reported in pregnant or postpartum women during week 14.

DSHS is requesting reporting of influenza-associated deaths in pregnant or postpartum (up to 6 weeks) women during the summer of 2010 and continuing throughout the 2010-2011 influenza season. There has been 1 death reported since the beginning of the summer 2010. All influenza types and subtypes should be reported; a positive rapid influenza test is sufficient for confirmation. 

School Closures and Institutional Outbreaks

No institutional outbreaks or school closures were reported during week 14. Information on the control of influenza in various settings may be found on the CDC website at http://www.cdc.gov/flu/professionals/infectioncontrol/.

U.S. Outpatient Influenza-like Illness Surveillance Network

Fifty-six 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 14. Of the 54 providers who saw patients, 30 (56%) saw at least one patient with ILI. Of all patient visits during this week, 2.99% were due to ILI. The Texas ILI baseline is 6.09% for the 2010-2011 season. The ILI baseline for HHS Region 6 (Arkansas, Louisiana, New Mexico, Oklahoma, and Texas) of the United States is 4.9% for the 2010–2011 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. The baselines displayed on the graph below were calculated for the official influenza reporting season only (approximately October to May).

National Influenza Activity Map

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

International Influenza Activity

The CDC compiles information from several sources and releases an international influenza summary. This report can be found at http://www.cdc.gov/flu/international/activity.htm. 

¹Influenza activity level corresponds to current MMWR week only and does not reflect previous weeks' activity.
²The majority of influenza cases are not reportable by law to the Texas Department of State Health Services. This map contains data from sentinel sites and does not represent all influenza cases in the state.
³Positive laboratory results are reported according to specimen collection date or date received in the lab if the former is unknown.

2010 - 2011 Texas Influenza Surveillance Information --- Flu Reports

For the week ending: 10/09/10; 10/16/10; 10/23/10; 10/30/10; 11/06/10; 11/13/10; 11/20/10; 11/27/10; 12/04/10; 12/11/10; 12/18/10; 12/25/10; 01/01/11; 01/08/11; 01/15/11; 01/22/11; 01/29/11; 02/05/11; 02/12/11; 02/19/11; 02/26/11; 03/05/11; 03/12/11; 03/19/11; 03/26/11; 04/02/11; 04/09/11;

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