Short-term exposure to air pollution and Mycoplasma pneumoniae infection risk: a distributed lag nonlinear analysis

BACKGROUND: Short-term impacts of ambient air pollution on Mycoplasma pneumoniae (MP) infections are understudied. This study explored exposure-lag-response associations between key air pollutants and MP infections in Jinhua, China. METHODS: Daily MP cases (2023-2024), air pollutant and meteorological data were collected. Quasi-Poisson regression with distributed lag non-linear models analyzed six pollutants' non-linear/delayed effects (0-21 lags) with confounder adjustment, and sex/age subgroup analyses were conducted. RESULTS: A total of 154,697 MP infections were reported. NO₂, CO, PM₁₀ and PM₂.₅ were positively correlated with daily MP cases, while O₃ showed a negative correlation. NO₂, PM₁₀ and PM₂.₅ had the strongest lag effects within 0-7 days, with immediate RRs (lag 0) of 1.136, 1.104 and 1.105, and substantial 21-day cumulative RRs of 1.947, 1.867 and 2.599, respectively. Subgroup analyses revealed children aged 0-14 years had the highest susceptibility to the pollutants. CONCLUSIONS: Short-term exposure to NO₂, PM₁₀ and PM₂.₅ significantly increases MP infection risk, especially in children, emphasizing the necessity of targeted air quality interventions.