Weekly U.S. Influenza Surveillance Report | Seasonal Influenza (Flu) | CDC

Weekly U.S. Influenza Surveillance Report | Seasonal Influenza (Flu) | CDC

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 5, ending February 4, influenza activity increased in the United States with widespread influenza activity reported in 43 states and Puerto Rico.

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2016-2017 Influenza Season Week 5 ending February 4, 2017

All data are preliminary and may change as more reports are received.

Synopsis:

During week 5 (January 29-February 4, 2017), influenza activity increased in the United States.

• Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 5 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: Five influenza-associated pediatric deaths were reported.
• Influenza-associated Hospitalizations: A cumulative rate for the season of 24.3 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. New York City and 23 states experienced high ILI activity; 10 states experienced moderate ILI activity; Puerto Rico and eight states experienced low ILI activity; nine 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 six states reported regional activity; the District of Columbia and one state reported local activity; and the U.S. Virgin Islands reported no activity.