To investigate the clinical characteristics, pathogen spectrum, and epidemic patterns of severe pneumonia patients, and to analyze the association between different pathogen spectrum infections and severe pneumonia with respiratory failure.

This study systematically reviewed all hospitalized children diagnosed with severe pneumonia at Changzhou Children's Hospital from December 2020 to March 2024. By extracting medical history, we described the basic characteristics, age distribution, pathogen spectrum, and comorbid respiratory failure of children with severe pneumonia, compared the differences in respiratory failure among children infected with different pathogens, and used multiple logistic regression analysis to explore the impact of different pathogen spectra on respiratory failure in children with severe pneumonia.

During the study period, 2 177 children with severe pneumonia were included. Among them, 319 (14.65%) had respiratory failure. Compared with the period before 2023, the number of children hospitalized with severe pneumonia has increased sharply since 2023, with rises observed across different pathogens and age groups. Notably, the increase was most pronounced for severe pneumonia patients caused by Mycoplasma pneumoniae (MP), which accounted for 51.92% (962/1 853) of all severe pneumonia patients since 2023. Among 319 children with severe pneumonia complicated with respiratory failure, MP infection accounted for 17.55% (56/319), and 49.22% (157/319) were infants aged ≤ 1 year. Multivariate analysis identified age, low birth weight, spring season, bacterial-bacterial co-infection, and bacterial-viral co-infection as risk factors for respiratory failure in children with severe pneumonia (all P < 0.05).

During the 2023-2024 period, the number of severe pneumonia patients caused by various pathogens increased significantly, with MP being the main cause. However, severe pneumonia due to MP infection rarely leads to respiratory failure. Infants under one year old are likely to be a high-risk group for severe pneumonia with respiratory failure. Additionally, bacterial-bacterial and bacterial-viral co-infections may be important risk factors for this complication in children.