Nonbacterial Respiratory Pathogens Following the Easing of COVID-19 Restrictive Measures.

Nonbacterial respiratory pathogens are major acute respiratory infection (ARI) agents in children. We aimed to characterize the epidemiological changes in 11 common nonbacterial pathogens after easing COVID-19 restrictions in Zhejiang, China, to guide prevention and treatment. A retrospective study was conducted on children with ARIs at Children's Hospital, Zhejiang University School of Medicine in 2023, and epidemiological characteristics were analyzed for gender, age, month, sampling method, and immune status. In total, 59.48% of the children identified pathogens, and Mycoplasma pneumoniae ranked first. Various pathogens showed new features regarding detection rates, seasonal patterns, and susceptible populations. The host age, onset time, sampling method, and immunity status affected the mixed infection rate and unusual coinfection pairs emerged. The epidemiology of respiratory pathogens among children in Zhejiang has changed with local characteristics, and possible preventive actions are needed.