2017-2018 Influenza Season Week 1 ending January 6, 2018
January 14th, 2018During week 1 (December 31, 2017-January 6, 2018), influenza activity increased in the United States.
- Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 1 was influenza A(H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories remained elevated.
- Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was at the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
- Influenza-associated Pediatric Deaths: Seven influenza-associated pediatric deaths were reported.
- Influenza-associated Hospitalizations: A cumulative rate of 22.7 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 10 states experienced moderate ILI activity; the District of Columbia and six states experienced low ILI activity; and eight states experienced minimal ILI activity.
- Geographic Spread of Influenza:The geographic spread of influenza in 49 states was reported as widespread; Guam and one state reported regional activity; the District of Columbia reported local activity; the U.S. Virgin Islands reported sporadic activity; and Puerto Rico did not report.
