Weekly U.S. Influenza Surveillance ReportFull report also available as PDF
2016-2017 Influenza Season Week 8 ending February 25, 2017
All data are preliminary and may change as more reports are received.
During week 8 (February 19-25 2017), influenza activity remained elevated in the United States.
- Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 8 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 above the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
- Influenza-associated Pediatric Deaths: Six influenza-associated pediatric deaths were reported.
- Influenza-associated Hospitalizations: A cumulative rate for the season of 39.4 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 4.8%, which is above the national baseline of 2.2%. All 10 regions reported ILI at or above their region-specific baseline levels. 27 states experienced high ILI activity; four states experienced moderate ILI activity; New York City, Puerto Rico and six states experienced low ILI activity; 13 states experienced minimal ILI activity; and the District of Columbia had insufficient data.
- Geographic Spread of Influenza: The geographic spread of influenza in Puerto Rico and 43 states was reported as widespread; Guam and five states reported regional activity; the District of Columbia and two states reported local activity; and the U.S. Virgin Islands reported sporadic activity.
Weekly U.S. Influenza Surveillance Report
The CDC Influenza Division collects, compiles, and analyzes information on Influenza activity year-round in the US and produces FluView, a weekly influenza surveillance report. During week 8, ending February 25, influenza activity increased in the United States with widespread activity reported by 27 states.