Weekly U.S. Influenza Surveillance Report

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2016-2017 Influenza Season Week 52 ending December 31, 2016

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

Synopsis:

During week 52 (December 25-31, 2016), influenza activity increased in the United States.

Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 52 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: No influenza-associated pediatric deaths were reported.
Influenza-associated Hospitalizations: A cumulative rate for the season of 4.9 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 3.4%, which is above the national baseline of 2.2%. Nine regions reported ILI at or above their region-specific baseline levels. New York City, Puerto Rico, and 10 states experienced high ILI activity; 10 states experienced moderate ILI activity; five states experienced low ILI activity; 25 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
Geographic Spread of Influenza: The geographic spread of influenza in 12 states was reported as widespread; Guam and 28 states reported regional activity; the District of Columbia and 10 states reported local activity; the U.S. Virgin Islands reported sporadic activity; and Puerto Rico did not report.

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 52, ending December 31, New York City, Puerto Rico, & 10 states (AL, GA, LA, MO, NJ, NY, OK, OR, SC, & UT) experienced high activity.

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