High Influenza Incidence and Disease Severity Among Children and Adolescents Aged <18 Years ― United States, 2022–23 Season
Elizabeth B. White, Alissa O’Halloran, Devi Sundaresan, Matthew Gilmer, Ryan Threlkel, Arielle Colón, Katie J. Tastad, Shua J. Chai, Nisha B. Alden, Kimberly Yousey‐Hindes, Kyle P. Openo, Patricia Ryan, Sue Kim, Ruth Lynfield, Nancy Spina, Brenda L. Tesini, Marc A. Martinez, Zachary Schmidt, Melissa Sutton, H. Keipp Talbot, Mary Hill, Matthew Biggerstaff, Alicia Budd, Shikha Garg, Carrie Reed, A. Danielle Iuliano, Catherine H. Bozio
Abstract
During the 2022-23 influenza season, early increases in influenza activity, co-circulation of influenza with other respiratory viruses, and high influenza-associated hospitalization rates, particularly among children and adolescents, were observed. This report describes the 2022-23 influenza season among children and adolescents aged <18 years, including the seasonal severity assessment; estimates of U.S. influenza-associated medical visits, hospitalizations, and deaths; and characteristics of influenza-associated hospitalizations. The 2022-23 influenza season had high severity among children and adolescents compared with thresholds based on previous seasons' influenza-associated outpatient visits, hospitalization rates, and deaths. Nationally, the incidences of influenza-associated outpatient visits and hospitalization for the 2022-23 season were similar for children aged <5 years and higher for children and adolescents aged 5-17 years compared with previous seasons. Peak influenza-associated outpatient and hospitalization activity occurred in late November and early December. Among children and adolescents hospitalized with influenza during the 2022-23 season in hospitals participating in the Influenza Hospitalization Surveillance Network, a lower proportion were vaccinated (18.3%) compared with previous seasons (35.8%-41.8%). Early influenza circulation, before many children and adolescents had been vaccinated, might have contributed to the high hospitalization rates during the 2022-23 season. Among symptomatic hospitalized patients, receipt of influenza antiviral treatment (64.9%) was lower than during pre-COVID-19 pandemic seasons (80.8%-87.1%). CDC recommends that all persons aged ≥6 months without contraindications should receive the annual influenza vaccine, ideally by the end of October.