Respiratory pathogen detections and codetection patterns among 2,253 children hospitalized with community-acquired pneumonia in China, 2022–2025: a prospective multicenter surveillance study

Community-acquired pneumonia (CAP) remains a leading cause of childhood hospitalization, and the distribution of respiratory pathogens may have changed following the COVID-19 pandemic. Understanding contemporary pathogen detection patterns in pediatric CAP in China is important for optimizing diagnostic strategies and clinical management. We conducted a prospective, multicenter surveillance study involving 17 clinical departments from 16 hospitals across 14 Chinese cities from October 2022 to June 2025. A total of 2253 hospitalized children aged 1–14 years with CAP were enrolled. Respiratory pathogens were detected using a standardized protocol integrating multiplex real-time PCR for common respiratory viruses, serum MP-IgM testing for Mycoplasma pneumoniae, and conventional bacterial culture. The overall patient-level pathogen detection rate was 67.2% (1513/2253). Among the 2324 pathogen detection events, viral nucleic acid detections accounted for the largest proportion (45.1%, 1047/2324), followed by M. pneumoniae detection based on MP-IgM positivity (43.8%, 1017/2324) and bacterial culture detections (11.2%, 260/2324). The most frequently detected respiratory viruses with confirmed CAP relevance were HAdV, IBV, IAV, and RSV, whereas EBV was considered a frequent upper respiratory codetection without independent diagnostic criteria for EBV pneumonia. Pathogen codetection occurred in 36.2% (547/1513) of pathogen-positive children, with viral–M. pneumoniae codetection representing the predominant pattern (69.3%, 379/547). In multivariable generalized linear mixed models accounting for hospital-level clustering, viral detection, MP-IgM positivity, pathogen codetection, and bacterial positivity were independently associated with severe CAP. This prospective multicenter surveillance study characterized complex respiratory pathogen detection patterns among hospitalized children with CAP in post-pandemic China. Viral pathogens and M. pneumoniae represented the predominant detection categories, while pathogen codetection was frequently observed and independently associated with severe CAP. These findings provide epidemiological evidence supporting age-, region-, and severity-oriented diagnostic strategies for pediatric CAP and may inform public health considerations regarding influenza and RSV prevention.