Clinical Presentation of Pediatric Mycoplasma pneumoniae Before and After the COVID-19 Pandemic

OBJECTIVES: Mycoplasma pneumoniae (MP) is a prevalent bacterial respiratory pathogen known for cyclic epidemics every 3-5 years, potentially linked to waning immunity. Following the global decline post-coronavirus disease 2019, MP has re-emerged since late 2023. Given the extended interval since the last epidemic, we compared pediatric MP's clinical presentation and outcomes during the recent and previous outbreaks spanning 17 years at a tertiary center in Jerusalem, Israel. METHODS: We conducted a retrospective cohort study at Hadassah Medical Center, analyzing demographic, clinical and treatment data from pediatric patients (0-17 years) with PCR-confirmed MP. In 2024, daily reports updated physicians on positive cases. We compared 2024 data (221 patients) with cohorts from 2007 to 2017 (352 patients) and initial epidemic years (2012, 2015; 139 patients). RESULTS: The 2024 epidemic showed an increased median age (8.0 vs. 5.8 years; P = 0.0002), higher female prevalence (56% vs. 44%; P = 0.007), and altered clinical manifestations: increased cough (78% vs. 63%; P = 0.0002), fever (79% vs. 64%; P = 0.0004), consolidation on x-ray (48% vs. 39%; P = 0.0244) and pleural effusions (5% vs. 0%; P < 0.0001). Rash incidence decreased (8% vs. 16%; P = 0.0031). Significant differences in age, sex, pleural effusions and rash persisted when comparing initial epidemic years. Early emergency department diagnosis rose in 2024 from 43% to 80%. The hospitalization rate decreased from 70% to 30% and was overall lower than 2007-2017 (81%; P < 0.001). CONCLUSIONS: Pediatric MP presentation in 2024 differed notably from prior epidemics, marked by increased severe pneumonia in older children. Enhanced awareness facilitated rapid diagnostics, reducing hospital admissions, unnecessary tests and inappropriate antibiotic use.