Outbreak of Mycoplasma pneumoniae infection in Lebanon during 2023-2024.

BACKGROUND

Mycoplasma pneumoniae is a leading cause of community-acquired pneumonia, especially in children and adolescents. After near disappearance during the COVID-19 pandemic, global outbreaks re-emerged in 2023-2024. However, regional data from the Middle East remain scarce.

OBJECTIVES

To characterize the clinical, radiological, and epidemiological features of M. pneumoniae infections during the 2023-2024 outbreak in Lebanon.

METHODS

This is a retrospective chart review conducted at the American University of Beirut Medical Center between October 10, 2023, and July 19, 2024. All patients with laboratory-confirmed M. pneumoniae infection by IgM and/or PCR were included. Demographics, clinical presentations, laboratory and imaging findings, treatment, and outcomes were analyzed.

RESULTS

Of 1201 tests, 233 (19.4%) were positive for M. pneumoniae. Cases surged in March 2024, peaked in June (48.4% positivity), and declined by July. The majority of cases (62.2%) occurred in school-aged children (5-17 years). Fever, cough, and systemic symptoms predominated. Despite the broad clinical spectrum, outcomes were favorable: complications were rare (4.7%), and no deaths occurred. Imaging most often showed unilateral lower lobe involvement. Macrolide monotherapy was the leading treatment approach, yet 16% of patients recovered without antibiotics. Severe outcomes were significantly associated with older age, active neoplasms and neurological disease.

CONCLUSION

M. pneumoniae outbreak emerged in Lebanon during 2023-2024, spanning late winter to early summer. The outbreak affected both pediatric and adult populations and was characterized by a broad clinical spectrum but overall favorable outcomes. Strengthening diagnostic capacity, promoting judicious antibiotic use, and establishing regional surveillance systems are essential to ensure timely outbreak recognition and effective public health response.