OBJECTIVE To explore the clinical characteristics of Mycoplasma pneumoniae pneumonia (MPP) after COVID-19 epidemic so as to offer help for early clinical diagnosis and treatment.

METHODS The clinical data that were collected from the MPP patients who were treated in the fever clinic of the First Medical Center of Chinese PLA General Hospital from Jul. 2023 to Aug. 2024 were retrospectively analyzed. The results of laboratory tests for the different age groups of patients complicated with other pathogens were statistically analyzed.

RESULTS Of totally 161 MPP patients who were enrolled in the study, 78 (48.85%) were male, and 83 (51.55%) were female; the average age was (32.98±14.35) years old, and the patients aged between 20 and 40 years old accounted for 43.48% (70 cases). The enrolled patients were divided into the simple MPP group with 92 (57.14%) cases and the MPP+ mixed group with 69 (42.86%) cases according to the result of etiological test of sputum; the patients of MPP+ mixed group were divided into the MPP + bacteria group with 42(60.87%) cases, the MPP+fungi group with 10(14.49%) cases, and the MPP+ viruses group with 17(24.64%)cases. There was significant difference in the age among the groups(P<0.05); there were no significant differences in the sex, white blood cell counts and percentage of mononuclear cells among the groups, the percentage of lymphocytes was highest in the simple MPP group, the levels of C-reactive protein (CRP) and interleukin-6 (IL-6) were highest in the MPP + bacteria group, and there were significant differences (P<0.05). All of the patients were divided into three groups: the ≤20-year-old group the >20-40-year old group and the >40-year-old group. There were no significant differences in the white blood cell counts, percentage of lymphocytes, percentage of mononuclear cells and IL-6 level among the three groups, and the CRP level was highest in the >20-40-year old group(P=0.025). Random forest model analysis showed that the weight of CRP was highest (22.65%) among the clinical characteristics of the MPP patients, which played a key role in construction of model. As for other factors, the weight of age was 17.02%, the percentage of lymphocytes 15.34%, the white blood cells counts 14.86%, the percentage of mononuclear cells 14.39%, the IL-6 13.61%, the gender 2.13%.

CONCLUSION MPP maintains common among the patients aged less than 40 years old after the COVID-19 epidemic, nearly half of the patients are complicated with the infections of other pathogens, and CRP is more helpful for the clinical diagnosis and treatment of the MPP in early stage.