Impact of the COVID-19 pandemic on the epidemiologic characteristics of Mycoplasma pneumoniae infection in children: an eight-year retrospective study

Objective To investigate the epidemiological characteristics of MP infection in hospitalized children with community-acquired pneumonia before, during, and after the outbreak of the new coronary pneumonia epidemic in Zhengzhou, China, and to provide a theoretical basis for the prevention and treatment of MP infection.Methods Hospitalized children who were diagnosed with CAP and underwent MP-PCR from January 2017 to December 2024 were retrospectively analyzed as study subjects. We analyzed the prevalence characteristics of MP among hospitalized children with CAP of different genders, ages and different epidemic periods, and analyzed the clinical characteristics of children admitted to ICUs in different epidemic periods.Results A total of 110,801 children with CAP were included in the study, and 33,108 children were detected positive for MP, with an infection rate of 29.88%. The detection rate of MP positivity in male children was significantly lower than that in female children (28.73% vs. 31.39%, χ2 = 665.998, p < 0.001).MP positivity tended to increase with age (χ2 = 90.215, p<0.001). The macrolide resistance rate was 88.78% (15,294/17,214), and there was no statistically significant difference in the resistance rate between male and female children (88.90% vs. 88.78%, χ² = 0.06, p = 0.808). There was a difference in macrolide resistance rate between age and seasonal groups (p<0.001).There was a significant decrease in the positive detection rate of MP during the pandemic period of COVID-19 (15.55%), and a sharp increase in the positive detection rate of MP after the pandemic period of COVID-19 (41.22%). Regardless of the pre-epidemic, epidemic and post-epidemic periods, the prevalence of MP infection tended to increase with age, and the rate of MP positivity was significantly higher in female children than in males. In the postepidemic period, the proportion of infants and preschool children with MPP decreased, the proportion of school-age children increased significantly, and the proportion of ICU admissions decreased.Conclusions The detection rate of MP was significantly lower during the COVID-19 pandemic, and non-pharmacological interventions can be used to suppress the prevalence of MP infection during the period of high prevalence of MP infection. School-age children were the main population with MP infection, especially after the COVID-19 pandemic, and the detection rate of Mp resistance gene (23S rRNA) mutation was high, and the detection rate of macrolide resistance gene was the lowest in children under 1 year old.