A-Z Index × Submit A-Z Index × Submit A-Z Index Search Dropdown × Submit Facebook Twitter LinkedIn Syndicate Emerging Infectious Disease journal ISSN: 1080-6059 Disclaimer: Early release articles are not considered as final versions. Any changes will be reflected in the online version in the month the article is officially released.
Post–COVID-19 pandemic Mycoplasma pneumoniae resurgences have occurred globally and have been particularly severe in Taiwan. We conducted a multicenter study to assess M. pneumoniae trends in children. Compared with the 2019 peak, 2024 data revealed a doubling of incidence (546/100,000 population), a 2.2-fold increase in intensive care unit admissions (10.9/100,000 population), and a 13.7-fold surge in central nervous system complications (6.1/100,000 population). In a 2023–2024 prospective cohort (n = 226), intensive care unit admission risk factors were neutrophils >7,000/μL (adjusted odds ratio [aOR] 6.2 [95% CI 1.3–29.9]), platelets >400 × 10 3 /μL (aOR 12.5 [95% CI 2.7–57.9]), pleural effusion (aOR 9.7 [95% CI 1.6–58.1]), and central nervous system involvement (aOR 27.9 [95% CI 4.1–188.3]). Phylogenetic analysis of 698 genomes demonstrated that 4 emerging subclades replaced pre–COVID-19 lineages by mid-2024; 1 subclade was associated with severe outcomes, highlighting evolving resistant, neurotropic lineages and calling for enhanced surveillance.
After the height of the COVID-19 pandemic, Mycoplasma pneumoniae respiratory infections did not reemerge as quickly as influenza or respiratory syncytial virus did, likely because of the pathogen’s long incubation period, long periodicity, and slow growth rate ( 1 ). M. pneumoniae activity increased markedly in mid-2023, leading to unprecedented epidemics and varying disease severity across multiple countries worldwide. In parts of Europe and the United States, where macrolide resistance remains <10%, an increase in severe pediatric cases has been reported in Spain, England, and Texas (USA), but not in the Netherlands, Norway, or Denmark ( 2 – 5 ). France and Switzerland documented high rates of intensive care unit (ICU) admissions among adults ( 6 , 7 ). In contrast, a highly publicized outbreak in China was notable for an exceptionally high macrolide resistance rate (90%–100%) and a substantial burden of severe disease, primarily affecting children ( 8 ). Although prolonged fever is frequently reported in macrolide-resistant M. pneumoniae infections, an increased risk for complications or ICU admission compared with macrolide-sensitive strains has not been consistently demonstrated ( 9 , 10 ). Nevertheless, M. pneumoniae is increasingly associated with severe clinical manifestations, irrespective of macrolide resistance, although the role of genetic evolution in that trend remains unclear. Timely diagnosis and initiation of appropriate therapy are crucial to reducing disease duration and preventing progression to severe illness requiring intensive care ( 7 ).
Taiwan has a high prevalence of macrolide-resistant M. pneumoniae ; resistance rates reached 70% before the COVID-19 pandemic ( 10 ). In this multisite study, we assessed the effects of the 2023–2024 resurgence among children by comparing the incidence of hospitalization, ICU admission, and neurologic complications across 8 seasons from 2017 through 2024. We also analyzed molecular genetic changes in M. pneumoniae and risk factors associated with severe disease in the post&ndas…