Synopsis: During week 19 (May 10-16, 2015), influenza activity continued to decrease in the United States.

o Viral Surveillance : Of 6,553 specimens tested and reported by U.S. World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance System (NREVSS) collaborating laboratories during week 19, 228 (3.5%) were positive for influenza.

o Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the epidemic threshold.

o Influenza-associated Pediatric Deaths: Three influenza-associated pediatric deaths were reported, including two influenza-associated pediatric death s that occurred during the 2013-14 season.

o Influenza-associated Hospitalizations: A cumulative rate for the season of 65.5 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported.

o Outpatient Illness Surveillance : The proportion of outpatient visits for influenza-like illness (ILI) was 1.3%, which is below the national baseline of 2.0%. All 10 regions reported ILI below region-specific baseline levels. Puerto Rico and one state experienced low ILI activity; New York City and 49 states experienced minimal ILI activity; and the District of Columbia had insufficient data.

o Geographic Spread of Influenza : The geographic spread of influenza in one state was reported as widespread; Guam and one state reported regional activity; Puerto Rico and nine states reported local activity; the District of Columbia and 31 states reported sporadic activity; and the U.S. Virgin Islands and eight states reported no influenza activity.

Stephen B. Thacker CDC Library collection

United States