Abstract
BACKGROUND: Mycoplasma pneumoniae (MP), characterized by periodic outbreaks, causes community-acquired pneumonia in Chinese children. Non-pharmaceutical interventions (NPIs) during the coronavirus disease 2019 (COVID-19) pandemic significantly altered MP transmission. Following the relaxation of NPIs, MP infections rebounded globally, with trends toward younger individuals and increased severity. In this study, we aimed to identify new changes in the epidemiological characteristics, clinical phenotypes, and treatment strategies of MP infection in the post-pandemic era in China. METHODS: In this retrospective study, we analyzed the clinical data of 541 pediatric patients with MP nucleic acid samples who were treated at a general hospital in Chongqing, China between January 2018 and December 2024. Participants were divided into an observation group [2023-2024] and a control group [2018-2022] based on their hospitalization dates. Differences in the group characteristics were compared. RESULTS: After the relaxation of NPIs, the 2023 hospitalization rate was 5.1 times higher than that before the pandemic (11.16% vs. 2.29%). The peak age of onset shifted from 5-15 to 3-7 years. The observation group had a significantly higher proportion of severe cases (74.34% vs. 40.00%), more intense fever and cough symptoms, multilobar involvement (66.89%), and a higher post-discharge residual cough rate (64.69% vs. 20.00%). In the observation group, tetracycline usage increased (57.38% in children <8 years), glucocorticoid use increased (63.82% vs. 23.53%), and treatment duration was extended. CONCLUSIONS: The post-pandemic era witnessed a surge in MP infections in younger patients, with more severe cases requiring adjusted treatment strategies. This study provides critical evidence for the clinical management and public health decision-making for MP pneumonia.