Analysis of the correlation between PM2.5 and PM10 concentrations and the epidemiology of severe Mycoplasma pneumoniae in the PICU

This study aimed to analyze the epidemiological characteristics of severe Mycoplasma pneumoniae in the pediatric intensive care unit (PICU) of Hunan Children's Hospital from 2020 to 2023. This study investigated the epidemiological patterns related to different years, seasons, ages, and sexes, as well as the correlations of PM_2.5, PM₁₀, and NO₂ concentrations, temperature, and humidity with severe Mycoplasma pneumoniae. The goal is to increase awareness of the prevention and control of severe Mycoplasma pneumoniae in the Changsha region, thereby improving clinical outcomes, reducing mortality rates among patients with severe cases, and providing evidence-based guidance for clinical practice. A retrospective analysis was conducted on children diagnosed with severe Mycoplasma pneumoniae in the PICU of Hunan Children's Hospital from January 2020 to December 2023. The study compared the positivity rates of Mycoplasma infections across different years, seasons, age groups, and sexes. The correlations between PM_2.5 (µg/m³), PM₁₀ (µg/m³), NO₂ (µg/m³), average temperature (°C), and average relative humidity (%) and the number of cases of severe Mycoplasma pneumoniae were also analyzed. Among 2,047 children with severe pneumonia, the overall MP-IgM positivity rate was 9.5%. Annual positivity rates increased from 6.3% in 2020 to 15.7% in 2023. Rates were highest in summer (15.8%), and preschool children (3-7 years) showed the greatest positivity (30.0%). At pollutant concentrations above thresholds (PM_2.5 ≥35 µg/m³, PM₁₀ ≥ 50 µg/m³, NO₂ ≥ 25 µg/m³), moderate positive correlations with severe cases were found, with risk ratios of 1.28, 1.31, and 2.04 per 10 µg/m³ increase, respectively. The positivity rate and number of cases of severe Mycoplasma pneumoniae in the PICU tended to increase from 2020 to 2023. The condition was most prevalent in summer and among preschool-aged children. When the PM_2.5 concentration was ≥ 35 µg/m³ or the PM₁₀ concentration was ≥ 50 µg/m³, moderate positive correlations were observed between the PM_2.5 and PM₁₀ concentrations and the number of severe Mycoplasma pneumoniae cases.