Emerging Trends in Streptococcal Toxic Shock Syndrome, Japan.

Japan experienced substantial increases in streptococcal toxic shock syndrome and group A Streptococcus pharyngitis after relaxing COVID-19 restrictions in May 2023. Increased detection of the M1UK lineage of Streptococcus pyogenes, especially in the vicinity of Tokyo, emphasizes the need to raise awareness of disease characteristics and epidemiologic trends.