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Streptococcus pyogenes emm Type 3.93 Emergence, the Netherlands and England

Matthew A Davies, Brechje de Gier, Rebecca L Guy

    Emerging Infectious Diseases
    |February 21, 2025
    PubMed

    Insights

    A new invasive group A Streptococcus (iGAS) strain, emm3.93, rapidly emerged globally in late 2023. While not increasing mortality, it is linked to severe childhood iGAS infections like pneumonia and meningitis.

    Area of Science:

    • Microbiology
    • Infectious Diseases
    • Genomics

    Background:

    • Global increase in invasive group A Streptococcus (iGAS) infections observed post-COVID-19 restrictions, with M1UK dominating.
    • Seasonal decline in iGAS incidence during summer 2023 preceded a new strain's emergence.

    Purpose of the Study:

    • To investigate the rapid expansion of a previously rare emm type 3.93 of iGAS.
    • To characterize the clinical associations and genomic features of the emm3.93 strain.
    • To highlight the importance of molecular surveillance in public health.

    Main Methods:

    • Analysis of iGAS incidence data from England and the Netherlands.
    • Genomic analysis of historic and contemporary emm3.93 isolates using long-read sequencing.

    Main Results:

    • A rapid, simultaneous expansion of emm3.93 was observed starting November 2023.
    • emm3.93 became a significant cause of iGAS in children (6-17 years), associated with increased risk of pneumonia, pleural empyema, and meningitis.
    • No increased mortality risk was associated with emm3.93 compared to other iGAS types.
    • Genomic analysis revealed 3 new clades of emm3.93 with potentially advantageous configurations.

    Conclusions:

    • Molecular surveillance, including advanced sequencing techniques, is crucial for identifying emerging infectious disease threats.
    • The emm3.93 strain represents a significant public health concern due to its rapid spread and association with severe pediatric iGAS infections.
    Keywords:
    EnglandNetherlandsStreptococcus pyogenesbacteriaepidemiologygenomic inversioninvasive infectionmeningitis/encephalitispneumoniastreptococci

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