Monday, November 30, 2009

CDC FluView Week 46

 

# 4103

 

 

 

The CDC has posted FluView for week 46, ending November 21st, 2009. The amount of flu activity we are seeing has decreased from the levels of a couple of weeks ago, but is still much higher than normally seen this time of year.

 

P&I (pneumonia & Influenza) deaths remain above the epidemic level for this time of year, and 35 pediatric influenza-related deaths were added last week.

 

I’ve excerpted some of the data and graphs below, but follow the link to read it in its entirety.  

 

 

 

FluView: A Weekly Influenza Surveillance Report Prepared by the Influenza Division

2009-2010 Influenza Season Week 46 ending November 21, 2009

All data are preliminary and may change as more reports are received.

Synopsis:

During week 46 (November 15-21, 2009), influenza activity continued to decrease in the U.S.

  • 1,880 (20.5%) specimens tested by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories and reported to CDC/Influenza Division were positive for influenza.
  • Over 99% of 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 eighth consecutive week.
  • Thirty-five influenza-associated pediatric deaths were reported. Twenty-seven of these deaths were associated with 2009 influenza A (H1N1) virus infection, seven were associated with an influenza A virus for which the subtype was undetermined, and one was associated with a seasonal influenza A (H1) virus infection that occurred in March.
  • The proportion of outpatient visits for influenza-like illness (ILI) was 4.3% which is above the national baseline of 2.3%. All 10 regions reported ILI above region-specific baseline levels.
  • Thirty-two states reported geographically widespread influenza activity, Puerto Rico and 17 states reported regional influenza activity, the District of Columbia and one state reported local influenza activity, and Guam and the U.S. Virgin Islands reported sporadic influenza activity.

 

 

U.S. Virologic Surveillance:

WHO and NREVSS collaborating laboratories located in all 50 states and Washington D.C., report to CDC the number of respiratory specimens tested for influenza and the number positive by influenza type and subtype. The results of tests performed during the current week are summarized in the table below.

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During week 46, seasonal influenza A (H1N1) and influenza B viruses co-circulated at low levels with 2009 influenza A (H1N1) viruses. Over 99% of all subtyped influenza A viruses reported to CDC this week were 2009 influenza A (H1N1) viruses.

 

 

Pneumonia and Influenza (P&I) Mortality Surveillance

During week 46, 8.2% of all deaths reported through the 122-Cities Mortality Reporting System were due to P&I. This percentage was above the epidemic threshold of 7.0% for week 46. Including week 46, P&I mortality has been above threshold for eight consecutive weeks.

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Influenza-Associated Pediatric Mortality

Thirty-five influenza-associated pediatric deaths were reported to CDC during week 46 (California, Colorado, Florida [3], Illinois [3], Indiana, Kentucky, Massachusetts, Minnesota, Missouri, New Hampshire, New Mexico [8], New York, North Carolina [2], Pennsylvania [2], Rhode Island [2], South Carolina [2], Tennessee, Texas [2], and Washington). Twenty-seven of these deaths were associated with 2009 influenza A (H1N1) virus infection, seven were associated with an influenza A virus for which the subtype is undetermined, and one was associated with a seasonal influenza A (H1) virus infection. The deaths reported during week 46 occurred between March 8 and November 21, 2009.

 

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Influenza-Associated Pediatric Mortality