Mycoplasma pneumoniae infection: characterization of the 2024 outbreak

Abstract

Mycoplasma pneumoniae is responsible for respiratory tract infection outbreaks globally every 3-5 years being particularly prevalent among school-aged children. The aim of this retrospective study was to investigate the epidemiological characteristics of Mycoplasma pneumoniae infection in children after the COVID-19 pandemic and characterize the 2024 outbreak. In this study, we used a population of children from 0 to 18 years old who went to a tertiary Portuguese hospital from August 2022 to October 2024. Respiratory samples were collected and Mycoplasma pneumoniae was defined as detected when positive by real-time polymerase chain reaction (RT-PCR). The results showed a significant increase of infected children during the post COVID-19 pandemic due to an outbreak started in late summer of 2023 until early of 2024. We observed a noteworthy variation of infection through the years, with positive infection detection rate increasing from 0% in 2022 and 0.7% in 2023 up to 10.1% in 2024. Children aged 6-10 years were the most affected with an infection positive rate of 12% in 2023 and 27.9% in 2024. Different molecular approaches were used including syndromic panels that were responsible for the early detection of the outbreak. This study contributed to a comprehensive and in-depth understanding of the recent outbreak of Mycoplasma pneumoniae and supports the necessity for multiplex RT-PCR for accurate diagnosis and control. Furthermore, it highlights the importance of continuous pathogen monitoring in providing effective prevention and control policies reducing the extent of Mycoplasma pneumoniae infections and epidemics.