Invasive group A Streptococcal infections in Franche-Comté, France (2022-2023)

Following the withdrawal of COVID-19-related barrier measures, a sharp rise in group A streptococcal (GAS) circulation has been reported in several countries. To describe a series of invasive group A streptococcal (iGAS) infections in a French region after the COVID-19 pandemic. We conducted a descriptive retrospective study on confirmed and probable cases of iGAS that occurred between September 2022 and August 2023 in six public hospitals in Franche-Comté (France). A total of 116 patients (99 adults and 17 children) were analysed. The main clinical presentations of iGAS infections were skin and soft tissue infections (31%), osteoarticular infections (20%), pulmonary infections (15%), and isolated bacteraemia (13%). The main associated risk factors were age >65 years (42%) and acute and chronic wounds (38%) in adults, and respiratory viral co-infections (29%) and chickenpox (24%) in children. Streptococcal toxic shock syndrome (STSS) occurred in 24% of patients, and 27% required admission to an intensive care unit. Mortality rate was 22%. Regarding therapy, 39% of patients received beta-lactam combined with anti-toxin antibiotics. No resistance to beta-lactam was observed. GAS emm1 genotype predominated (59%) and was involved in 79% of STSS. Our study illustrates the diversity of clinical presentations and the severity of iGAS post-COVID-19. Early recognition of STSS and appropriate management is essential to improve the prognosis of these infections.