2017-2018 Influenza Season Week 46 ending November 18, 2017
November 29th, 2017Synopsis:
During week 46 (November 12-18, 2017), influenza activity increased in the United States.
- Viral Surveillance: The most frequently identified influenza virus type reported by public health laboratories during week 46 was influenza A. The percentage of respiratory specimens testing positive for influenza in clinical laboratories is increasing.
- Novel Influenza A Virus: One human infection with a novel influenza A virus was reported.
- 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: Five influenza-associated pediatric deaths were reported, one of which occurred during the 2016-17 season.
- Influenza-associated Hospitalizations: A cumulative rate of 1.4 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 2.0%, which is below the national baseline of 2.2%. Regions 1, 2, 4 and 6 reported ILI at or above region-specific baseline levels. Two states experienced high ILI activity, one state experienced moderate ILI activity, New York City and 4 states experienced low ILI activity, the District of Columbia and 43 states experienced minimal ILI activity, and Puerto Rico had insufficient data.
- Geographic Spread of Influenza:The geographic spread of influenza in two states was reported as widespread; Guam and six states reported regional activity; 20 states reported local activity; the District of Columbia, the U.S. Virgin Islands and 21 states reported sporadic activity; one state reported no activity; and Puerto Rico did not report.