H3N2 flu rising in U.S. and raising concern in Canada

U.S. health officials report about 7.5 million H3N2 infections this season and roughly 81,000 hospitalizations; Health Canada will publish its next flu update next week.

H3N2 influenza is reported to be increasing hospital admissions in the United States, according to U.S. health officials. The U.S. Centers for Disease Control and Prevention estimates about 7.5 million Americans have been infected this season and roughly 81,000 have been hospitalized. Data show test positivity and hospital admissions have risen in recent weeks, and Canadian figures are also up compared with earlier reporting. Health Canada has said it will release an updated flu report next week that includes the holiday period. Key reported figures: - CDC estimate of about 7.5 million infections and roughly 81,000 hospitalizations this season in the U.S. - Test positivity in the U.S. week ending Dec. 20 was reported at about 25.6 percent. - For the week ending Dec. 13, Canada recorded 11,646 new detected cases and a test positivity of about 27.7 percent. - Reported hospitalization rates in Canada nearly doubled compared with the prior week of available data. - The dominant strain this season in both countries is reported as H3N2 subclade K. Summary: Rising H3N2 infections are associated with increased hospital admissions in the U.S. and higher detection rates in Canada. Health Canada will release an updated flu report next week that will include holiday-period data.