We report a 21-fold increase in group A Streptococcus meningitis in adults in Denmark during October 13, 2022-April 12, 2023, concurrent with an outbreak of invasive streptococcal disease. We describe clinical characteristics of the outbreak cases and prognosis for patients in comparison to those for previous sporadic cases.
Keywords: Denmark; bacteria; epidemiology; group A Streptococcus; meningitis/encephalitis.