Characteristics of <em>Mycoplasma pneumoniae</em> Pneumonia in Romanian Children

Background/Objectives: Mycoplasma pneumoniae (M pneumoniae), traditionally associated with mild community-acquired pneumonia in school-aged children, has experienced a delayed resurgence following the COVID-19 pandemic. The epidemiological and clinical characteristics of M. pneumoniae pneumonia in children within the context of this global resurgence have not been well-established in Romania. Materials and Methods: This retrospective, single-center study analyzed children diagnosed with M pneumoniae pneumonia who were hospitalized in the Pulmonology Department of &quot;Grigore Alexandrescu&quot; Emergency Hospital for Children in Bucharest from March to December 2024. Clinical, laboratory, and radiographic data were extracted from hospital records. M pneumoniae infection was confirmed through polymerase chain reaction (PCR) multiplex panel detection or specific IgM antibody levels ≥10 AU/mL. Results: The final analysis included 63 patients meeting inclusion criteria. The cohort&#039;s median age [IQR] was 12.6 [8-15] years, with 11.1% (n=7) under 6 years old. Radiographic findings revealed a predominance of right lung involvement (52.4%, n=33, p=0.03) and a significantly higher prevalence of alveolar infiltrates compared to interstitial patterns (88.9%, n=56, p&lt; 0.001). Antibiotic choice did not significantly affect hospitalization duration. Pleural effusion emerged as a common complication, occurring in 27% (n=17) of patients and associated with elevated admission leukocyte counts (p=0.007). Rare extrapulmonary manifestations included meningoencephalitis (1.6%, n=1) and reactive infectious mucocutaneous eruption (3.2%, n=2). Notably, co-infections with other respiratory pathogens did not extend hospital stays. Conclusion: This study contributes to the evolving global epidemiological profile of M pneumoniae infections in the post-pandemic era. It establishes a foundation for future multi-center analyses aimed at monitoring the changing epidemiology and clinical presentations of M pneumoniae infections in pediatric populations.