During week 2 (January 7-13, 2018), influenza activity increased in the United States.
January 19th, 2018During week 2 (January 7-13, 2018), influenza activity increased in the United States.
- Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 2 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 above the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
- Influenza-associated Pediatric Deaths: Ten influenza-associated pediatric deaths were reported
- Influenza-associated Hospitalizations: A cumulative rate of 31.5 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 6.3%, 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 32 states experienced high ILI activity; 9 states experienced moderate ILI activity; the District of Columbia and six 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.
