Analysis of antibody detection data of Mycoplasma pneumoniae in a hospital in Beijing City from 2017 to 2024

Objective  To explore the distribution characteristics of Mycoplasma pneumoniae (MP) antibody detection data in hospital, provide data reference for the prevention and control of MP infections. Methods  A single-center retrospective study was conducted on patients (aged 0 to 105 years) with suspected MP infection from the outpatient, emergency and inpatient departments of Peking University Third Hospital between March 2017 to February 2024. MP antibodies in patient serum were detected using passive agglutination.  χ² was used to analyze the differences in the positive rate of MP antibodies among different genders, ages, and seasons. Results  Among the 20 639 patients, the positive rate of MP antibodies was 23.19%(4 786/20 639),with a higher positive rate in females was 27.16%(2 540/9 353) compared to males (19.90%,2 246/11 286;χ²=151.191, P<0.01). The positive rate in children was 37.13%(2 731/7 356)significantly higher than in adults(15.47%, 2 055/13 283;χ²=1 246.433, P<0.01). The 6 to <12 year age group (63.11%,1 223/1 938) had the highest positive rate of MP antibodies, followed by 12 to <18 year old group (56.78%,385/678). The positive rate of MP antibodies increased with age from 0 to 12 years old but gradually decreased after 12 to <18 years old (χ² =3 848.393,P trend<0.01). The annual MP antibody positivity rates from 2017 to 2023 were 26.92%, 29.23%, 27.46%, 18.43%, 17.16%, 11.89%, and 23.72%, respectively, with statistically significant differences among the years (χ² = 387.519, P< 0.01). The MP antibody positive rate was high in autumn over the course of 7 years (χ² = 242.560, P< 0.01). The positive rates of MP antibodies for the years 2017-2019, 2020-2022, and 2023-2024 are (28.00%, 16.60%, 21.84%), respectively, with statistically significant differences among the three periods(χ²=295.845, P<0.01).The monthly positive rates of MP antibody in different years were (5.63% to 43.11%). In the MP antibody titer, qualitative testing was conducted on 4 563 patients and 16 076 patients had a semi-quantitative MP antibody titer of ≥1:160 with a positive rate of 16.03%(2 577/16 076). Among the proportion of children with high titers of MP antibodies ≥1:1 280 was 11.11%(798/7 182). Conclusion  The positive rates of MP antibodies in hospital in the Beijing area vary among different genders, ages, and seasons, with a higher incidence in autumn, mainly among children and adolescents.