Friday, November 13, 2009

FluView Week 44

 

# 4009

 

 

The CDC has posted FluView for week 44, ending November 7th, 2009. The level of activity we are seeing is roughly what we might expect during the height of the flu season, not during early November.

 

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

 

2009-2010 Influenza Season Week 44 ending November 7, 2009

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

Synopsis:

During week 44 (November 1-7, 2009), influenza activity decreased slightly in the U.S.

  • 3,834 (30.1%) 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.
  • 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.
  • Thirty-five influenza-associated pediatric deaths were reported. Twenty-six of these deaths were associated with 2009 influenza A (H1N1) virus infection, eight were associated with an influenza A virus for which the subtype was undetermined, and one 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.
  • Forty-six states reported geographically widespread influenza activity, Puerto Rico and four states reported regional influenza activity, the District of Columbia reported local influenza activity, Guam reported sporadic influenza activity, and the U.S. Virgin Islands did not report.

 

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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Pneumonia and Influenza (P&I) Mortality Surveillance

During week 44, 7.7% of all deaths reported through the 122-Cities Mortality Reporting System were due to P&I. This percentage was above the epidemic threshold of 6.8% for week 44. Including week 44, P&I mortality has been above threshold for six consecutive weeks.

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Influenza-Associated Pediatric Mortality

Thirty-five 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, eight were associated with an influenza A virus for which the subtype is undetermined, and one was associated with an influenza B virus infection. These deaths occurred between March 15 and November 7, 2009.

 

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.

 

Since August 30, 2009, CDC has received 117 reports of influenza-associated pediatric deaths that occurred during the current influenza season (18 deaths in children less than 2 years old, 12 deaths in children 2-4 years old, 41 deaths in children 5-11 years old, and 46 deaths in children 12-17 years old). Ninety-eight (84%)of the 117 deaths were due to 2009 influenza A (H1N1) virus infections, and the remaining 19 were associated with influenza A virus for which the subtype is undetermined. A total of 156 deaths in children associated with 2009 influenza A (H1N1) virus infection have been reported to CDC.

 

Among the 117 deaths in children, 65 children had specimens collected for bacterial culture from normally sterile sites and 18 (27.7%) of the 65 were positive; Staphylococcus aureus was identified in eight (44.4%) of the 18 children. One S. aureus isolate was sensitive to methicillin, six were methicillin resistant, and one did not have sensitivity testing performed. Thirteen (72.2%) of the 18 children with bacterial coinfections were five years of age or older, and five (27.8%) of the 18 children were 12 years of age or older.

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