CDC: During week 51 (December 17-23, 2017), influenza activity increased sharply in the United States.
December 30th, 2017During week 51 (December 17-23, 2017), influenza activity increased sharply in the United States.
- Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 51 was influenza A(H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories increased.
- Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
- Influenza-associated Pediatric Deaths: Three influenza-associated pediatric deaths were reported.
- Influenza-associated Hospitalizations: A cumulative rate of 8.7 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported.
- Outpatient Illness Surveillance:The proportion of outpatient visits for influenza-like illness (ILI) was 5.0%, which is above the national baseline of 2.2%. All 10 regions reported ILI at or above region-specific baseline levels. Twenty-one states experienced high ILI activity; New York City and five states experienced moderate ILI activity; eight states experienced low ILI activity; 14 states experienced minimal ILI activity; and the District of Columbia, Puerto Rico and two states had insufficient data.
- Geographic Spread of Influenza:The geographic spread of influenza in 36 states was reported as widespread; Puerto Rico and 13 states reported regional activity; one state reported local activity; and the District of Columbia, the U.S. Virgin Islands, and Guam did not report.
