Impact of COVID-19 on the epidemiological features of mycoplasma pneumoniae infection in children with community-acquired pneumonia in Ganzhou, China

Background The COVID-19 pandemic and non-pharmaceutical interventions (NPIs) have altered the global epidemiology of respiratory pathogens, including Mycoplasma pneumoniae (MP). However, the impact of MP infection on children with community-acquired pneumonia (CAP) in Ganzhou, China, remains unclear. This study aims to investigate the influence of the COVID-19 pandemic on the epidemiology and clinical outcomes of MP infection among hospitalized pediatric CAP patients in Ganzhou, China. Methods We retrospectively analyzed 27,369 hospitalized pediatric CAP patients (2017–2024), comparing MP positivity, seasonality, age distribution, and severity across pre-pandemic, NPIs, and post-NPIs phases. Results Among 27,369 CAP patients, 3,334 were MP-positive (12.18%). The positivity rate dropped during Phase II (3.78%, 158/4,183) then rebounded sharply in Phase III to 21.17% (2,385/11,268), exceeding the pre-pandemic baseline (χ²=45.65, p < 0.001). The seasonal pattern exhibited changes, with the spring positivity rate increasing from 4.06% (146/3,594) in Phase I to 19.94% (577/2,893) in Phase III (χ²=505.33, p < 0.001). Regarding age distribution, the 7–10 years age group showed the highest positivity rate 30.76% (638/2,074; χ²=1,789.43, p < 0.001). However, in Phase III, the 4–6 years group exhibited a significant rise to 29.79% (883/2,964), compared with 13.00% (184/1,415) in Phase I and 7.87% (41/521) in Phase II (χ²=226.65, p < 0.001). In the 1–3 years group, the proportion of severe pneumonia reached its highest numerical proportion in Phase II (14.55%, 8/55), which was significantly greater than the proportions in Phase I (2.56%, 8/313) and Phase III (10.21%, 82/803; χ²=20.08, p < 0.001). Notably, both the median hospitalization duration and the rate of mechanical ventilation for severe pneumonia were significantly higher in Phase I than in Phases II and III. Conclusion After the relaxation of NPIs, pediatric MP infections among hospitalized pediatric CAP patients in Ganzhou not only rebounded strongly but also exhibited a shift in epidemic peaks toward spring, alongside a notable change in susceptibility among younger children.