H1N1(Swine Flu): Finally, A Bit of Good News – A Slight Drop in Cases This Week

November 14, 2009

This week marks week 44 (November 1-7, 2009) and finally a slight decrease in the amount of influenza activity in the U.S.  The basic data includes:

  • All subtyped influenza A viruses being reported to CDC were 2009 influenza A (H1N1) viruses.
  • The proportion of deaths attributed to pneumonia and influenza (P&I) was above the epidemic threshold for the sixth consecutive week.
  • 35 influenza-associated pediatric deaths were reported.
    • 26 of these deaths were associated with 2009 influenza A (H1N1) virus infection
    • 8 were associated with an influenza A virus for which the subtype was undetermined
    • 1 was associated with an influenza B virus infection.
  • The proportion of outpatient visits for influenza-like illness (ILI) was 6.7%, which is above the national baseline of 2.3%. ‘
    • All 10 regions reported ILI above region-specific baseline levels.
  • 46 states reported geographically widespread influenza activity (down from the past few weeks which was stuck at 48)
    • Puerto Rico and four states reported regional influenza activity
    • The District of Columbia reported local influenza activity
    • Guam reported sporadic influenza activity
    • U.S. Virgin Islands did not report

Pneumonia and Influenza Hospitalization and Death Tracking:

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From August 30 – November 7, 2009, 22,364 laboratory-confirmed influenza associated hospitalizations and 877 laboratory-confirmed influenza associated deaths were reported to CDC. CDC will continue to use its traditional surveillance systems to track the progress of the 2009-10 influenza season.

Pediatric Deaths

 

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Three deaths reported during week 44, including the death associated with influenza B virus infection, occurred during the 2008-09 season, bringing the total number of reported pediatric deaths occurring during that season to 127.

  • 35 influenza-associated pediatric deaths were reported to CDC during week 44 (Alabama, Arizona, Arkansas [2], California [8], Delaware, Georgia, Illinois, Michigan [2], Missouri, New Jersey, Ohio [2], Oklahoma [3], Tennessee [2], Texas [6], Utah, Virginia, and Washington).
    • Twenty-six of these deaths were associated with 2009 influenza A (H1N1) virus infection
    • 8 were associated with an influenza A virus for which the subtype is undetermined
    • 1 was associated with an influenza B virus infection.

Outpatient Illness Surveillance:

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Nationwide during week 44, 6.7% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) were due to influenza-like illness (ILI). This percentage is above the national baseline of 2.3%.

Geographic Spread of Influenza as Assessed by State and Territorial Epidemiologists:

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A small drop this week from 48 to 46 states with widespread illness...

During week 44, the following influenza activity was reported:

  • Widespread influenza activity was reported by 46 states (Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Montana, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming).
  • Regional influenza activity was reported by Puerto Rico and four states (Hawaii, Mississippi, Nebraska, and Texas).
  • Local influenza activity was reported by the District of Columbia.
  • Sporadic influenza activity was reported by Guam.
  • The U.S. Virgin Islands did not report.

http://www.cdc.gov/flu/weekly/