Changes in pediatric pneumonia incidence and pathogen spectrum before, during, and after the COVID-19 pandemic: an eight-year inpatient data analysis from a tertiary hospital in Fujian, China

OBJECTIVE: To analyze the incidence and etiologic distribution of pediatric community-acquired pneumonia (CAP) in Fujian Province, China, across the periods before, during, and after the COVID-19 pandemic from 2017 to 2024. METHODS: We retrospectively analyzed 2,878 hospitalized pediatric CAP cases from 2017 to 2024. Cases were grouped into pre-pandemic (2017-2019), mid-pandemic (2020-2022), and post-pandemic (2023-2024) periods, and compared epidemiological and etiological characteristics. RESULTS: The overall pathogen positivity rate among children with pneumonia was 82.73%. In the pre-pandemic, mid-pandemic, and post-pandemic phases, the positivity rates were 88.22%, 68.90%, and 83.71%, respectively, with a statistically significant difference (P < 0.001). The predominant pathogens were Mycoplasma pneumoniae (MP, 36.31%), influenza virus (Flu, 20.29%), and respiratory syncytial virus (RSV, 2.26%). During the pandemic period, the overall infection rate, MP infection rate, and co-infection rate decreased significantly, whereas the proportion of RSV infections increased. In the post-pandemic period, MP infection rates increased markedly, along with a significant rise in both MP mono-infection and MP + Flu co-infection. The overall co-infection rate was 19.04%. Among co-infections, the most frequent combinations were MP+FluB and MP+FluB+FluA. Patients with co-infection involving Flu and MP had a higher proportion of severe pneumonia, compared to those with pure viral co-infection (FluB+FluA). CONCLUSION: This single-center study suggests that COVID-19 control measures were associated with temporal shifts in the pathogen spectrum of childhood pneumonia. Notably, infection rates decreased markedly during the pandemic, but rebounded post-pandemic, characterized by a surge in MP and co-infections alongside a decline in RSV. These findings highlight the need for sustained surveillance to optimize prevention and treatment strategies in the post-pandemic era.