Work

Nonlinear age-season dynamics and macrolide resistance of Mycoplasma pneumoniae: a large pediatric cohort study during the post-pandemic resurgence

Year: 2026

Type: article

Abstract: BACKGROUND: Mycoplasma pneumoniae (MP) is a major cause of community-acquired pneumonia in children and demonstrates distinct age- and season-dependent patterns. However, nonlinear risk profiles, the burden of severe complications, and macrolide resistance remain incompletely characterized in large pediatric cohorts. OBJECTIVE: To describe the epidemiological features of MP infection in a large pediatric pneumonia cohort, delineate nonlinear associations of age and season with MP-related risks, and evaluate macrolide resistance patterns and the burden of plastic bronchitis (PB). METHODS: We retrospectively analyzed MP qPCR results from pharyngeal swab specimens obtained from 175,350 children with acute respiratory infections. Targeted next-generation sequencing (tNGS) (n = 333) was conducted in a clinically selected subgroup of refractory/severe cases. Restricted cubic splines (RCS) and multivariable logistic regression assessed the nonlinear associations of age and month of onset with MP detection, hospitalization, and severe MPP risks. RESULTS: MP infection exhibited clear age- and season-dependent patterns. RCS analysis revealed a prominent nonlinear relationship with age, with a clinically meaningful inflection point at 8 years: in children ≤ 8 years, risk of MP detection, hospitalization, and severe MPP increased significantly with each additional year of age (adjusted ORs 1.335, 1.378, and 1.111, respectively; all p < 0.001), whereas risks plateaued or declined after age 8. School-aged children (6-12 years) accounted for the largest proportion of MP-positive cases (53.4%), while MP-infected infants had markedly higher hospitalization rates (84.3% vs. 22.3% in school-aged children, p < 0.001). Seasonally, risk rose progressively from May-June, peaked in September-October, and maintained high levels throughout the winter. In the clinically selected subgroup of refractory or severe cases, macrolide resistance was highly prevalent, with monthly detection ranging from 71.4% to 100%. PB occurred in 0.41% (115/28,178) of MP-positive cases, exclusively among those with severe Mycoplasma pneumoniae pneumonia (SMPP) (4.62% among documented SMPP cases during the study period). CONCLUSIONS: MP-related risks in children show distinct nonlinear patterns, with a peak around 8 years of age and a predominant high-risk window extending from autumn through winter. Macrolide resistance was highly prevalent (71.4%-100%) in a clinically selected subgroup of refractory/severe cases, underscoring the urgent need for rapid molecular diagnostics and alternative treatment strategies. Although uncommon, PB represents a severe complication of MPP that requires timely bronchoscopic intervention. CLINICAL TRIAL NUMBER: Not applicable.

Source: BMC Infectious Diseases

DOI: 10.1186/s12879-026-13380-w

Authors: Hongjia Chen, Yinghong Fan, Xu Zhang, Yijie Huang

Institutions: University of Electronic Science and Technology of China, Chengdu Women's and Children's Central Hospital

Language: English

Topic: Microbial infections and disease research

Subfield: Microbiology

Field: Immunology and Microbiology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,090