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

Synopsis: During week 8 (February 20-26, 2011), influenza activity in the United States remained elevated.

• Of the 7,543 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, 2,106 (27.9%) were positive for influenza.

• The proportion of deaths attributed to pneumonia and influenza (P&I) was at the epidemic threshold.

• Fourteen influenza-associated pediatric deaths were reported bringing the season total to 55. Four of these deaths were associated with an influenza B virus, four were associated with a 2009 influenza A (H1N1) virus, two were associated with an influenza A (H3) virus, and four were associated with an influenza A virus for which the subtype was not determined.

• The proportion of outpatient visits for influenza-like illness (ILI) was 4.0%, which is above the national baseline of 2.5%. All 10 regions reported ILI above region-specific baseline levels. Eighteen states experienced high ILI activity; six states experienced moderate ILI activity; New York City and 16 states experienced low ILI activity; 10 states experienced minimal ILI activity, and the District of Columbia had insufficient data.

External_F1108.pdf

Stephen B. Thacker CDC Library collection

United States