Weekly U.S. Influenza Surveillance Report
2016-2017 Influenza Season Week 1 ending January 7, 2017
All data are preliminary and may change as more reports are received.
During week 1 (January 1-7, 2017), 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 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 for the season of 7.1 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 3.2%, which is above the national baseline of 2.2%. All 10 regions reported ILI at or above their region-specific baseline levels. New York City, Puerto Rico, and eight states experienced high ILI activity; six states experienced moderate ILI activity; seven states experienced low ILI activity; 28 states experienced minimal ILI activity, and the District of Columbia and one state had insufficient data.
- Geographic Spread of Influenza: The geographic spread of influenza in Puerto Rico and 21 states was reported as widespread; Guam and 21 states reported regional activity; the District of Columbia and eight states reported local activity; and the U.S. Virgin Islands reported no activity.