Epidemiology and high-level macrolide resistance of Mycoplasma pneumoniae among children in Hangzhou, China: a 2024–2025 single-center surveillance study

Objective To analyze the epidemiological characteristics and macrolide resistance profile of Mycoplasma pneumoniae (MP) infections among children in Hangzhou during the post-COVID-19 period (2024–2025), providing evidence for precise clinical management. Methods We conducted a retrospective analysis of 12,380 respiratory specimens from patients at Hangzhou Children’s Hospital (March 2024 to December 2025). MP nucleic acid and the 23S rRNA A2063G/A2064G resistance mutations were detected using quantitative PCR. Positivity and resistance rates were analyzed across gender, age, care setting (inpatient/outpatient), and time. Results The overall MP positivity rate was 19.98% (2,473/12,380). Among positive cases, 86.94% (2,150/2,473) carried resistance mutations. Positivity rates did not differ significantly by gender (19.58% vs 20.41%, P  > 0.05). However, outpatients had a significantly higher positivity rate than inpatients (29.96% vs 18.96%; χ²=74.32, P  < 0.01), and a higher resistance rate (92.13% vs 86.10%; χ²=11.89, P  < 0.01). Infection rates exhibited a unimodal age distribution, peaking in children aged 6–12 years (27.90%-39.08%). Resistance rates exceeded 78% across all age groups. In 2024, the monthly resistance rate fluctuated between 74.89% and 94.20%. Conclusion During 2024–2025, MP infections in children showed distinct age clustering, with school-aged children at highest risk. Macrolide resistance was alarmingly prevalent (> 85%) and particularly prominent in outpatients. These findings underscore the need for enhanced resistance surveillance and optimized antibiotic stewardship in pediatric and outpatient settings.