2009 Flu Update

Synopsis:
During week 39 (September 27-October 3, 2009), influenza activity increased in the U.S.
•    2,968 (27.4%) 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.
•    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 at the epidemic threshold.
•    Nineteen influenza-associated pediatric deaths were reported. Sixteen of these deaths were associated with 2009 influenza A (H1N1) virus infection and three were associated with influenza A virus, for which subtype is undetermined.
•    The proportion of outpatient visits for influenza-like illness (ILI) was above the national baseline. Regions 3 through 10 reported ILI above region-specific baseline levels; Regions 1 and 2 were below region-specific baselines.
•    Thirty-seven states reported geographically widespread influenza activity, Guam and 11 states reported regional influenza activity, two states, the District of Columbia, and Puerto Rico reported local influenza activity, and the U.S. Virgin Islands did not report.