2017-2018 Influenza Season Week 52 ending December 30, 2017
January 10th, 2018Synopsis:
During week 52 (December 24-30, 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 52 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: One influenza-associated pediatric death was reported.
- Influenza-associated Hospitalizations: A cumulative rate of 13.7 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 5.8%, which is above the national baseline of 2.2%. All 10 regions reported ILI at or above region-specific baseline levels. New York City and 26 states experienced high ILI activity; Puerto Rico and nine states experienced moderate ILI activity; the District of Columbia and six states experienced low ILI activity; and nine states experienced minimal ILI activity.
- Geographic Spread of Influenza:The geographic spread of influenza in 46 states was reported as widespread; four states reported regional activity; the District of Columbia reported local activity; and Guam, Puerto Rico, and the U.S. Virgin Islands did not report.
