Epidemiology of Pediatric Invasive Group A Streptococcal Infections in 10 U.S. States, 2004–2023

BACKGROUND: Group A Streptococcus (GAS) infections are common in children, ranging from mild to life-threatening invasive disease. Large-scale descriptions of changes in pediatric invasive GAS infections in the United States, particularly during the COVID-19 pandemic, are limited. METHODS: We used CDC's Active Bacterial Core surveillance (ABCs), a multistate, population- and laboratory-based surveillance system, to assess changes in pediatric (<18 years old) invasive GAS incidence, clinical presentation, and bacterial strain characteristics from 2004-2023. Interrupted time series analysis was used to compare observed versus expected GAS incidence during 2020-2023, informed by trends before the COVID-19 pandemic (2004-2019). RESULTS: During 2004-2023, 2,856 invasive GAS cases were identified. Incidence remained stable from 2004-2019 (mean incidence 1.9 per 100,000), decreased in 2020 (1.0) and 2021 (0.6), and rebounded in 2022 (1.5) and 2023 (4.4). ICU admission increased from 2011 to 2023; case fatality remained stable. Penicillin resistance was not detected. Clindamycin non-susceptibility doubled from 2011 (3.8%) to 2022 (7.5%), before slightly decreasing in 2023 (6.4%). Infections due to emm1, the most frequently identified emm type in children with severe disease, almost disappeared in 2021 but surged in late 2022. CONCLUSIONS: After remaining stable for more than a decade, pediatric invasive GAS incidence declined during the COVID-19 pandemic and rebounded in 2022, more than doubling 2004-2019 incidence in 2023. While case fatality remained low, ICU admissions increased over time, highlighting the need for effective preventive measures such as vaccines. Increasing clindamycin non-susceptibility bears continued monitoring.