Abstract
<title>Abstract</title> <p>Objectives Mycoplasma pneumoniae (MP) is a leading cause of community-acquired pneumonia. Its epidemiology has shifted during and after the COVID-19 pandemic. Current evidence remains predominantly pediatric, creating a significant gap in systematic, all-age data—particularly among adults and hospitalized patients—which limits the development of tailored management strategies. This study employed a multicenter retrospective design to investigate hospitalized cases of MP infection across all age groups in the Hangzhou region of China. Methods Data were retrospectively obtained from inpatients at seven hospitals and four community health centers in Hangzhou, China. Patients of all age groups with acute respiratory tract infection and laboratory-confirmed MP infection were included. Epidemiological trends, age-specific incidence, co-infection pathogen spectra, and antimicrobial resistance-associated mutations patterns were analyzed. Results MP infection presented a “double-peak” pattern synchronous with acute respiratory infections, accounting for 5.2% of 99,730 included patients. Incidence remained < 5% in 2020–2021, increased rapidly, peaked at 12.3% in May 2024, and return to low levels. School-aged children most affected (48.6%); infections in older adults increased by five-fold. Most cases were single infections (83.5%), while 16.5% were co-infections, most commonly with adenovirus and Chlamydia pneumoniae, and the co-occurrence rate between parainfluenza virus and Chlamydia pneumoniae was as high as 73.8%. Macrolide resistance increased significantly, reaching 64.2% in 2023, primarily due to A2063G and A2064G mutations in the 23S rRNA gene. Conclusion The high burden in children, rising incidence in older adults, significant macrolide resistance, and distinct co-infection patterns highlight the need for enhanced, integrated surveillance and tailored stewardship strategies to manage MP infections.</p>