Group A streptococcal meningitis with the M1UKvariant in the Netherlands

We analyzed over 40 years of bacteriological surveillance data to reveal a 4-fold increase in Group A streptococcal (GAS) meningitis in 2022 compared to the annual average of 1982-2021 (n=5/year). Already 10 GAS meningitis cases occurred in 2023 (until March 13 th ). Molecular typing revealed that 25 out-of-29 (86%) isolates received in 2022 and 2023 were emm 1.0 (Figure 1). WGS analysis of 19 emm 1.0 isolates (2019 until 20 th December 2022) demonstrated that 15 out-of-19 (79%) isolates belonged to the toxicogenic M1 UK lineage. Based on these observations, we urge clinicians to be vigilant regarding clinical sign of meningitis with invasive GAS infections, since this disease manifestation appears to have a higher than expected occurrence due to clonal replacement by the recently-emerged M1 UK variant.