Weekly U.S. Influenza Surveillance Report
CDC's Influenza Division produces a weekly influenza surveillance report, FluView. According to this week's report (Jan 14-21), seasonal influenza activity increased in the United States. Thirty-two states and Puerto Rico experienced high Influenza Like Illness (ILI) activity levels. Nine states experienced moderate ILI activity.
2017-2018 Influenza Season Week 3 ending January 20, 2018
During week 3 (January 14-20, 2018), influenza activity increased in the United States.
- Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 3 was influenza A(H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories slightly increased.
- 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: Seven influenza-associated pediatric deaths were reported.
- Influenza-associated Hospitalizations: A cumulative rate of 41.9 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 6.6%, which is above the national baseline of 2.2%. All 10 regions reported ILI at or above region-specific baseline levels. New York City, Puerto Rico, and 39 states experienced high ILI activity; the District of Columbia and five states experienced moderate ILI activity; three states experienced low ILI activity; and three states experienced minimal ILI activity.
- Geographic Spread of Influenza:The geographic spread of influenza in Puerto Rico and 49 states was reported as widespread; Guam reported regional activity; the District of Columbia and one state reported local activity; and the U.S. Virgin Islands reported sporadic activity.