A 32-year-long surveillance study in Toronto has found a sharp increase in invasive group A streptococcus (iGAS) infections among children, with rates rising to the highest observed since 1992. The study, published in JAMA Network Open, highlights the need for a new vaccine as the M1UK variant accounted for most emm1 cases between 2019 and 2023.
According to the study, severe iGAS cases were first reported in North America in the late 1980s and have been associated with streptococcal toxic shock syndrome, necrotizing fasciitis, and high morbidity and mortality. The study analyzed data from 1992 to 2023 and found that annual incidence increased from 1.8 cases per 100,000 population in 1992 to 6.0 in 2023.
Researchers linked the post-pandemic rise to increased circulation of respiratory viruses, including influenza and SARS-CoV-2, which were detected in children with iGAS. The most common presentations were soft tissue infections and bacteremia without focus, while streptococcal toxic shock syndrome occurred in 5.8% of cases.
The study suggests that the surge in pediatric iGAS infections may reflect increased susceptibility among children due to reduced exposure to common pathogens during lockdowns. The new vaccine has completed Phase I trials with promising safety and immune response data, but a timeline for public availability has not been announced.
According to the researchers, over 90% of emm types identified are covered by the investigational 30-valent M protein vaccine, and coinfection with respiratory viruses was found in 32% of iGAS cases during 2022-2023. The study’s findings highlight the need for continued monitoring and public health measures to mitigate the spread of iGAS infections among children.
Source: https://medicalxpress.com/news/2025-04-surveillance-term-invasive-group-strep.html