Synopsis: During week 12 (March 17 – 23, 2013), influenza activity decreased in the United States. o Viral Surveillance: Of 5,332 specimens tested and reported by collaborating laboratories, 702 (13.2%) were positive for influenza. o Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was at the epidemic threshold. o Influenza-Associated Pediatric Deaths: Five pediatric deaths were reported. o Influenza-Associated Hospitalizations: A cumulative rate for the season of 41.8 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported. Of reported hospitalizations, 50% were among adults 65 years and older. o Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.8%. This is below the national baseline of 2.2%. Three of 10 regions reported ILI at or above region-specific baseline levels. One state experienced moderate activity; 3 states and New York City experienced low activity; 46 states experienced minimal activity, and the District of Columbia had insufficient data. o Geographic Spread of Influenza: Six states reported widespread influenza activity; Puerto Rico and 8 states reported regional influenza activity; the District of Columbia and 23 states reported local influenza activity; 11 states reported sporadic influenza activity; Guam and one state reported no influenza activity, and the U.S. Virgin Islands and one state did not report.

Stephen B. Thacker CDC Library collection