Weekly influenza reports

November 13, 2022 to November 19, 2022 (week 46)

• At the national level, influenza activity has continued to increase steeply as we enter the fourth week of the national influenza epidemic. Most surveillance indicators are increasing and all are above expected levels typical of this time of year.

Virologic

• In week 46, a total of 5,891 laboratory detections (5,876 influenza A and 15 influenza B) were reported.
• Among subtyped influenza A detections in week 46, 97% (2,213) were influenza A(H3N2) and 3% (73) were influenza A(H1N1).
• Among detections for which age information was reported in week 46 (3,256), 1,605 (49%) of detections were in individuals aged 0-19 years old.

Syndromic

• The percentage of visits for influenza-like illness (ILI) was 2.1% in week 46. The percentage visits for ILI is slightly above levels typical of this time of year.
• The percentage of FluWatchers reporting fever and cough was 2.9% in week 46. The percentage of FluWatchers reporting cough and fever is well above levels typical of this time of year.

Outbreaks

• From August 28, 2022 to November 19, 2022 (weeks 35 to 46), 127 laboratory-confirmed influenza outbreaks have been reported.

Severe Outcomes

• In recent weeks, the IMPACT network has reported a sharp increase in influenza-associated hospitalizations among the pediatric population. Currently, the weekly number of pediatric hospitalizations being reported is above levels typically seen at the peak of the influenza season. In week 46, 205 influenza-associated hospitalizations were reported.
• The highest cumulative hospitalization rates are among children under 5 years of age (26/100,000 population) and adults 65 years of age and older 21/100,000 population).