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 an 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.

External_F1205.pdf

Stephen B. Thacker CDC Library collection

United States