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

During week 7 (February 12-18 2017), influenza activity decreased slightly but remained elevated in the United States.

• Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 7 was influenza A (H3). The percentage of respiratory specimens testing positive for influenza in clinical laboratories decreased slightly but remained elevated.

• 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 33.7 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%. Nine regions reported ILI at or above their region-specific baseline levels. 27 states experienced high ILI activity; New York City and five states experienced moderate ILI activity; Puerto Rico and 10 states experienced low ILI activity; eight 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 44 states was reported as widespread; Guam and four states reported regional activity; the District of Columbia and one state reported local activity; one state reported sporadic activity; and the U.S. Virgin Islands reported no activity.

External_F1707.pdf

Stephen B. Thacker CDC Library collection

United States