Friday, February 10, 2012

FluView: Week 5

 

 

# 6134

 

 

According to the CDC’s latest FluView report, influenza activity is increasing across the United States but still remains below normal of this time of year.  Unlike reports we have been seeing out of Mexico over the past month, the predominant strain here is H3N2.

 

A few excerpts from this week’s report, the most striking of which (and most encouraging) is the near absence of pediatric deaths from influenza reported so far this year.

 

 

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2011-2012 Influenza Season Week 5 ending February 4, 2012

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

Synopsis:

During week 5 (January 29-February 4, 2012), influenza activity in the United States increased.

  • U.S. Virologic Surveillance: Of the 3,586 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, 378 (10.5%) were positive for influenza.
  • Pneumonia and Influenza (P&I) Mortality Surveillance: The proportion of deaths attributed to P&I was below the epidemic threshold.
  • Influenza-associated Pediatric Mortality: One influenza-associated pediatric death was reported and was associated with influenza A virus for which the subtype was not determined.
  • Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.7%, which is below the national baseline of 2.4%. Regions 7 and 10 reported ILI above region-specific baseline levels. One state experienced moderate ILI activity, 5 states experienced low ILI activity, New York City and 44 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
  • Geographic Spread of Influenza: One state reported widespread geographic activity; 9 states reported regional activity; 12 states reported local activity; the District of Columbia, Puerto Rico, and 27 states reported sporadic activity; Guam, the U.S. Virgin Islands and 1 state reported no influenza activity.

Pneumonia and Influenza (P&I) Mortality Surveillance:

During week 5, 7.3% of all deaths reported through the 122-Cities Mortality Reporting System were due to P&I. This percentage was below the epidemic threshold of 7.8% for week 5.

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Influenza-Associated Pediatric Mortality:

One influenza-associated pediatric death was reported to CDC during week 5 and was associated with influenza A virus for which the subtype was not determined. The death reported during week 5 occurred during the week ending January 21, 2012 (week 3). This brings the total of influenza-associated pediatric deaths reported during the 2011-12 season to 2.

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While it seems as if we are getting off unusually easy this year, there are still a couple of more months left in the traditional flu season, and as we saw in 2009, an off-season flu can also appear with little warning.