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

During week 2 (January 8-14, 2017), influenza activity increased in the United States.

• Viral Surveillance: The most frequently identified influenza virus subtype reported by public health laboratories during week 2 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: Two influenza-associated pediatric deaths were reported.

• Influenza-associated Hospitalizations: A cumulative rate for the season of 10.2 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 3.3%, 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 six states experienced high ILI activity; Puerto Rico and eight states experienced moderate ILI activity; 14 states experienced low ILI activity; 22 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 29 states was reported as widespread; Guam and 17 states reported regional activity; the District of Columbia and four states reported local activity; and the U.S. Virgin Islands reported sporadic activity.

External_F1702.pdf

Stephen B. Thacker CDC Library collection

United States