June 4, 1997

Update: Influenza Activity—United States and Worldwide, 1996-97 Season, and Composition of the 1997-98 Influenza Vaccine

JAMA. 1997;277(21):1666-1667. doi:10.1001/jama.1997.03540450022012

IN COLLABORATION with the World Health Organization (WHO), its international network of collaborating laboratories, and state and local health departments, CDC conducts surveillance to monitor influenza activity and to detect antigenic changes in the circulating strains of influenza viruses. This report summarizes surveillance for influenza in the United States and worldwide during the 1996-97 influenza season and describes the composition of the 1997-98 influenza vaccine.

United States  Influenza activity began in October 1996, increased at the end of November, peaked during late December through early January 1997, and decreased slowly through March. The number of state and territorial epidemiologists who reported regional* or widespread activity peaked at 38 during the week ending January 4,1997. Widespread activity was last reported for the week ending March 22; only two states (Alaska and Arizona) reported regional activity for the week ending April 5. The percentage of