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 20, ending May 20, flu activity decreased. While the 2016-2017 flu season has peaked, Arizona reported low influenza-like illness activity.

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Weekly U.S. Influenza Surveillance Report

Full report also available as PDF

2016-2017 Influenza Season Week 20 ending May 20, 2017

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

Synopsis:

During week 20 (May 14-20, 2017), influenza activity decreased in the United States.

Viral Surveillance: The most frequently identified influenza virus type reported by public health laboratories during week 20 was influenza B. The percentage of respiratory specimens testing positive for influenza in clinical laboratories decreased.
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: Three influenza-associated pediatric deaths were reported.
Influenza-associated Hospitalizations: A cumulative rate for the season of 65.2 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 1.3%, which is below the national baseline of 2.2%. All ten regions reported ILI below their region-specific baseline levels. One state experienced low ILI activity; New York City, Puerto Rico, and 49 states experienced minimal ILI activity; and the District of Columbia had insufficient data.
Geographic Spread of Influenza: The geographic spread of influenza in Guam and two states was reported as regional; Puerto Rico and nine states reported local activity; the District of Columbia and 34 states reported sporadic activity; and the U.S. Virgin Islands and five states reported no activity.