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

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

Flu activity is low in the United States, but CDC has received reports of early outbreaks in institutions across the country. Most of these outbreaks have been attributed to H3N2 viruses. Flu causes millions of illnesses, hundreds of thousands of hospitalizations and thousands of deathsevery season.

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2015-2016 Influenza Season Week 45 ending November 14, 2015

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

Synopsis:

During week 45 (November 8-14, 2015), influenza activity increased slightly in the United States.

• Viral Surveillance: The most frequently identified influenza virus type reported by public health laboratories in week 45 was influenza A viruses, with influenza A (H3) viruses predominating. The percentage of respiratory specimens testing positive for influenza in clinical laboratories is low.
• Pneumonia and Influenza Mortality: The proportion of deaths attributed to pneumonia and influenza (P&I) was below their system-specific epidemic threshold in both the NCHS Mortality Surveillance System and the 122 Cities Mortality Reporting System.
• Influenza-associated Pediatric Deaths: One influenza-associated pediatric death was reported.
• Outpatient Illness Surveillance: The proportion of outpatient visits for influenza-like illness (ILI) was 1.6%, which is below the national baseline of 2.1%. Two of 10 regions reported ILI at or above region-specific baseline levels. One state experienced moderate ILI activity; Puerto Rico and two states experienced low ILI activity; New York City and 47 states experienced minimal ILI activity; and the District of Columbia had insufficient data.
• Geographic Spread of Influenza: The geographic spread of influenza in Guam was reported as widespread; Puerto Rico reported regional activity; four states reported local activity; 40 states reported sporadic activity; and the District of Columbia, the U.S. Virgin Islands, and six states reported no influenza activity.