TOPLINE:
Post-COVID Mycoplasma pneumoniae infections in children were associated with increased frequencies of obstructive diseases and pleural effusions but no change in severe outcomes vs the pre-COVID period.
METHODOLOGY:
- Researchers conducted a retrospective, comparative cohort study in Zurich to assess evolving features of M pneumoniae infections in children since its delayed re-emergence after COVID non-pharmaceutical interventions (NPIs).
- The study included 321 children (age range, 0 to < 18 years) with polymerase chain reaction (PCR)-detected M pneumoniae infection: 83 were included in the pre-NPI period (April 2015 to March 2020), two in the NPI period (April 2020 to March 2022), and 236 in the post-NPI period (April 2022 to March 2025).
- Clinical features were compared between periods using the Kruskal-Wallis rank sum or Fisher’s exact test; hospitalisation and ICU admission rates were analysed using generalised linear models adjusted for age, sex, and underlying diseases, with patients stratified by NPI period.
- Primary outcomes focused on comparing changes in clinical features and disease severity between the pre- and post-NPI periods; secondary outcomes included rates of hospitalisation and ICU admission.
TAKEAWAY:
- Patients included in the post-NPI period were older (median age, 9.05 vs 8.20 years; P = .30) and presented with significantly more chest pain (8.9% vs 2.4%; P = .05) and pleural effusions (45.7% vs 28.9%; P = .02) than those in the pre-NPI period.
- The frequency of obstructive diseases was higher post-NPI than pre-NPI (18.6% vs 9.6%; P = .059), whereas extrapulmonary manifestations (18.6% vs 30.1%; P = .043), particularly dermatologic (15.7% vs 25.3%) and neurologic (1.3% vs 4.8%) manifestations, were less frequent post-NPI than pre-NPI.
- Although hospitalisation rates were similar post-NPI and pre-NPI (38.6% vs 43.9%), generalised linear models showed a trend towards fewer hospitalisations post-NPI (odds ratio [OR], 0.72; 95% CI, 0.42-1.23; P = .22); a similar trend was seen for ICU admissions (5.1% vs 4.9%; OR, 0.90; 95% CI, 0.29-3.34; P = .86).
- Disease severity remained unchanged, with no deaths and comparable rates of long-term sequelae (6.3% post-NPI vs 6.0% pre-NPI; P = 1.00).
IN PRACTICE:
“Concerns about a more severe disease course of re-emerging infections were not confirmed. However, the observed changes in the clinical characteristics of M pneumoniae infections highlight the need for continuous monitoring of these clinical phenotypes,” the authors of the study wrote.
SOURCE:
This study was led by Elena Robinson, Division of Infectious Diseases and Hospital Epidemiology, University Children’s Hospital Zurich, University of Zurich in Zurich, Switzerland. It was published online on August 07, 2025, in European Journal of Pediatrics.
LIMITATIONS:
The study was restricted to a single Swiss centre, which may have limited its generalisability. Although the targeted testing strategy remained consistent throughout, the shift from singleplex to multiplex PCR testing after October 2020 could have affected co-detection rates.
DISCLOSURES:
The study was supported by open access funding provided by the University of Zurich. The authors declared no competing interests.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.