A retrospective analysis of 266 cases: clinical features of Chlamydia pneumoniae pneumonia in children

BACKGROUND: Chlamydia pneumoniae is a significant pathogen in pediatric community-acquired pneumonia, with increasing incidence globally, particularly in East Asia. However, gender disparities and the role of bronchoscopy in disease management remain underexplored. This study aimed to analyze the clinical features, risk factors, and outcomes of C. pneumoniae pneumonia in children. METHODS: We conducted a retrospective analysis of 266 children with C. pneumoniae pneumonia admitted to a tertiary maternal and child health hospital from January 2024 to June 2025. Data included age, gender, fever at admission, cough duration, length of stay, bronchoscopy performance, hematological parameters (white blood cell count, neutrophil ratio, lymphocyte ratio), C-reactive protein, procalcitonin, pulmonary involvement, co-infection status, and medication use. Statistical analyses involved t-tests, chi-square tests, and logistic regression. RESULTS: A significant surge in cases was observed since January 2025. Gender-based analysis showed girls (n = 127) had longer hospitalization (mean difference:7.0, p < 0.05) and cough duration at admission (median value: 7, p < 0.05), with higher co-infection rates (48% vs. 30.9% in boys, n = 139, p < 0.05). Among 102 co-infected cases, rhinovirus was predominant (37.3%, n = 38). Logistic regression identified younger age as an independent risk factor for co-infection (OR 0.91 per year, p < 0.05). Children undergoing bronchoscopy (n = 86) had prolonged hospital stays, lower lymphocyte and monocyte ratios, and higher neutrophil ratios (p < 0.05). Bronchoscopic findings revealed viscous yellowish secretions, which were looser than Mycoplasma pneumoniae-induced plastic bronchitis and effectively managed with lavage. Younger age and lower neutrophil ratios predicted multi-lobar involvement (p < 0.05). CONCLUSION: C. pneumoniae pneumonia in children exhibits gender-specific severity, with girls showed trends of prolonged hospitalization and cough duration. Younger age increases co-infection risk, and bronchoscopy indicates more severe disease but aids in targeted therapy. These findings underscore the need for early diagnosis and personalized interventions in high-risk groups.