Prevalence and Distribution of Respiratory Pathogens in Paediatric Acute Respiratory Infections After the Cessation of Strict Non-Pharmaceutical Interventions in Putian, China.

Background Acute respiratory infections (ARIs) are a significant cause of morbidity in children. This study aimed to investigate the prevalence and distribution of respiratory pathogens in paediatric ARIs in Putian, China, following the cessation of strict non-pharmaceutical interventions (NPIs). Methods A total of 3,790 paediatric patients with suspected ARIs were included in the study. Nasopharyngeal swabs were collected and analyzed using RT-PCR to identify 13 common respiratory tract pathogens. Statistical analyses were performed to examine the distribution of pathogens among patients stratified by sex, age, and season. Results The overall pathogen positivity rate was 78.9%. No significant difference in detection rates was observed between males (79.7%) and females (77.9%). The highest positivity rate was found in the school-age group, with elevated rates noted during autumn and winter. Among the positive cases, 81.9% had a single pathogen, with Mycoplasma pneumoniae (Mp) being the most common (33.6%), followed by Human rhinovirus (HRV) and Human respiratory syncytial virus (HRSV). Age-dependent distribution indicated that Influenza A (InfA) was more prevalent in preschool and school-age children, whereas HRSV was most prevalent in infants. Temporal distribution showed that InfA peaked in spring, while Mp, Human metapneumovirus (HMPV), and Human adenovirus (HADV) were most common in winter. Co-infections were more frequent in autumn and winter, with the HRV + Mp co-infection being the most prevalent pattern. Conclusion The prevalence of respiratory pathogens in children with ARI has returned to pre-COVID-19 pandemic levels following the discontinuation of stringent NPIs. Additionally, the epidemiology of certain pathogens has shifted from traditional patterns. These findings underscore the dynamic nature of respiratory pathogen distribution and highlight the necessity for ongoing surveillance to inform effective treatment and prevention strategies for ARIs in children.