Epidemiology of Invasive Group A Streptococcal Infection in Children and its Association With Community Circulation of Scarlet Fever and Respiratory Viral Infections.

BackgroundStreptococcus pyogenes (group A Streptococcus, GAS) is a common pediatric pathogen causing a wide range of diseases with significant morbidity and mortality. GAS infections exhibit strong seasonal patterns, and the invasive forms (iGAS) have historically been associated with influenza. Since September 2022, a global outbreak of both iGAS and noninvasive GAS infections has been reported.MethodsThis is a retrospective observational multicentric study of children (