Notes from the Field: Increase in Pediatric Invasive Group A Streptococcus Infections — Colorado and Minnesota, October–December 2022

Abstract

During fall 2022, a resurgence of invasive group A Streptococcus (iGAS) infection in children and adolescents was observed in two of CDC's Emerging Infections Program (EIP)* surveillance sites: Colorado (Denver metropolitan area) and Minnesota (entire state). This increase followed historic declines in invasive bacterial diseases during 2020, concurrent with mitigation strategies implemented during the COVID-19 pandemic † (1). Whereas reports of iGAS increased among all age groups, including adults, the increase among children and adolescents was notable, occurred earlier than seasonal increases during previous years, and accompanied a resurgence in hospitalizations for respiratory viral illnesses such as respiratory syncytial virus (RSV) and influenza. Viral infections, such as influenza and varicella, have been identified as risk factors for iGAS infection in children, adolescents, and adults (2) and can be reduced by vaccination.Surveillance for iGAS is conducted by 10 U.S. sites as part of EIP's Active Bacterial Core surveillance (ABCs). § An analysis of cases among Colorado and Minnesota EIP site residents aged <18 years who met criteria for iGAS ¶ was conducted using ABCs data from the Colorado and Minnesota surveillance sites. Case counts, age distribution, and clinical characteristics of patients with iGAS infection were compared over three periods:

Molecular epidemiology of invasive Group A Streptococcal infections before and after the COVID-19 pandemic in Switzerland

“…After a historically low incidence of GAS infections during the COVID-19 pandemic, an alarmingly increasing incidence of invasive GAS (iGAS) infections has been reported, since October 2022, in many European countries and in the USA, mostly among children under 10 years of age, including many fatalities [4][5][6][7]. Also in Switzerland, since November 2022, a fourfold increase of the registered iGAS infections in children, including four deaths, has been reported compared to the pre-COVID-19 pandemic era [8].…”

Postpandemic Rebound in Noninvasive Group a Streptococcal Disease is not Synchronous with Winter RSV and Influenza Epidemics

“…An increase in group A Streptococcus (GAS) infections, particularly invasive group A Streptococcus (iGAS) disease and also scarlet fever, was reported in Europe and United States in 2022, above seasonally expected levels, with commensurate increase in number of deaths. 1–9 An analysis of pediatric iGAS in Portugal, from September 2022 to February 2023, has also shown significantly higher number of cases than in the same period of prepandemic years. It was not associated with an emerging new lineage but with multiple lineages previously circulating in Portugal, with a clear dominance of the M1 UK sublineage and emm 12.…”

“…Decreased exposure to group A Streptococci during the COVID-19 pandemic and intense circulation of resurgent respiratory viruses with frequent viral coinfections in children presenting with iGAS infection, in particular respiratory syncytial virus (RSV), influenza virus and varicella virus, have been proposed as explanations for this observation. 1–4…”

A Longitudinal Study of Group A Streptococcal Colonization and Pharyngitis in US Children

“…1,7,8 Recent years have seen outbreaks of more severe GAS. 9,10 GAS is also the leading cause of childhood-acquired heart disease worldwide. In 5-14-year-old children, GAS results in 336,500 cases of acute rheumatic fever, an estimated 282,000 new cases of rheumatic heart disease (RHD), and >233,000 associated deaths annually.…”