Multicenter Study on the Prevalence of Human Respiratory Syncytial Virus Coinfection and Disease Burden Among Hospitalized Children Aged 5 Years and Younger - 5 Prefecture-level Cities, Zhejiang Province, China, 2018-2023.

Human respiratory syncytial virus (HRSV) coinfection with other respiratory pathogens frequently occurs in young children with acute respiratory illness. However, the epidemiological patterns and associated disease burden of HRSV coinfections in pediatric populations remain poorly characterized. Analysis of hospitalized children under 5 years in Zhejiang Province from 2018 to 2023 revealed that 20.4% experienced HRSV coinfections, with bacterial coinfections substantially exceeding viral coinfections (14.1% vs. 5.3%). M. pneumoniae and S. pneumoniae emerged as predominant bacterial copathogens, while human rhinovirus and cytomegalovirus were the most prevalent viral coinfection agents. HRSV coinfections were associated with significantly higher disease burden compared to HRSV monoinfection [median expense: 4,971.4 Chinese Yuan (CNY) vs. 4,649.1 CNY; P<0.05]. Implementation of comprehensive prevention strategies, including vaccination programs, nonpharmaceutical interventions, and enhanced surveillance of multiple respiratory pathogens, is essential to reduce HRSV coinfections and their associated disease burden during periods of high respiratory pathogen circulation.