# The impact of the COVID-19 pandemic on the epidemiology, clinical manifestations and molecular characteristics of Mycoplasma pneumoniae

## TL;DR

The study examines how the COVID-19 pandemic affected the spread and severity of Mycoplasma pneumoniae infections in children, highlighting rising antibiotic resistance and changes in disease patterns.

## Contribution

The paper provides a comprehensive review of global changes in Mycoplasma pneumoniae epidemiology and clinical features before, during, and after the pandemic.

## Key findings

- The epidemic season of Mycoplasma pneumoniae has lengthened with a displaced peak.
- Severe Mycoplasma pneumoniae pneumonia and macrolide resistance rates have increased, especially in East Asia.
- Disease severity is linked to host inflammation and the CARDS toxin, with changes in co-infection profiles observed.

## Abstract

Mycoplasma pneumoniae (MP) is a major causative agent of acute respiratory tract infections in children. Since 2023, its high prevalence coupled with rising rates of macrolide resistance has presented substantial challenges in the clinical management of pediatric MP infections. In light of the impact of the COVID-19 pandemic on the epidemiology of respiratory pathogens, this article reviews relevant global studies conducted before, during, and after the pandemic. A comprehensive narrative review approach was adopted, with literature searches conducted in databases including PubMed and Web of Science up to December 2025.The findings reveal notable shifts in the epidemiology of MP in the post-pandemic period: the epidemic season has lengthened with a displaced peak, the proportion of cases among school-aged children has risen, and the incidence of severe Mycoplasma pneumoniae pneumonia (SMPP) has increased. Globally, macrolide-resistant Mycoplasma pneumoniae (MRMP) rates continue to climb, remaining especially high in East Asia (>80%), and are closely linked to specific genotypes such as P1–1 and M4572. Disease severity is associated with both host-derived exaggerated inflammatory responses (e.g., elevated IL-6 and LDH) and the virulence activity of the CARDS toxin. The profile of co-infections has also undergone change. In summary, against a background of reduced pathogen exposure and the formation of immune intervals and high antimicrobial resistance, the COVID-19 pandemic has compounded the clinical complexity of managing MP infections. Future efforts should prioritize enhanced global surveillance, the development of rapid diagnostics and novel therapeutics, and the optimization of antibiotic stewardship strategies.