Post-Pandemic Surge of Group A Strep Infections in Children

TOPLINE:

Data over a 32-year period showed that the incidence of invasive group A streptococcal (iGAS) infections in children remained stable before 2011, increased until 2020, declined during the pandemic, and subsequently sharply rose in 2023, with a notable surge contributed by respiratory tract infections.

METHODOLOGY: 

• Researchers evaluated the incidence and clinical characteristics of iGAS infections among children over a 32-year period ( January 1, 1992, to December 31, 2023) using population-based surveillance data from Canada.
• They included data of 498 children with iGAS infections (median age, 5.1 years; 60.2% boys; 30.7% with comorbidities), sourced from hospitals providing care and laboratories processing the samples.
• Analyses included the incidence of iGAS infections by clinical presentations, disease severity, infecting emm types, and antimicrobial resistance patterns within the population.

TAKEAWAY:

• The mean annual incidence of iGAS infections (events per 100,000 people) was nearly stable from 1992 to 2001 and from 2002 to 2011 (1.83 and 1.70, respectively) and increased from 2012 to 2019 (2.38). During the 2021 COVID-19, it significantly dropped to 0.51 but sharply increased to 6.05 in 2023.
• Children younger than 5 years were more likely to have had chickenpox 3 weeks before infection (odds ratio [OR], 5.61) and bacteremia without a specific focus (OR, 1.92). Children aged 5-9 years were more likely to have bone or joint infections (OR, 2.19).
• Incidences of iGAS infections with primary respiratory tract focus, especially pneumonia, increased overtime. Children younger than 5 years with positive respiratory virus test results showed higher rates of pneumonia than those with negative results (OR, 28.11).
• The emm1 strain showed a stronger association with pneumonia (OR, 1.99) and bone or joint infections (OR, 1.70), whereas the emm4 strain showed a stronger association with bacteremia without focus (OR, 6.10).

IN PRACTICE:

“This study also emphasizes the importance of considering age-specific factors in the clinical presentation of iGAS infections, reinforces the value of varicella vaccination in preventing iGAS, and highlights the potential for both respiratory viral and GAS vaccines to alleviate the burden of iGAS infections,” the authors wrote.

“The post-pandemic surges in GAS infections and our lack of understanding of the associated pathogen molecular changes should serve as a clarion call for a renewed emphasis in active pathogen surveillance, the study of transmission dynamics, and pathogen emergence,” the authors of an invited commentary wrote.

SOURCE:

This study was led by Halima Dabaja-Younis, MD, Infection Prevention and Control Unit, Sinai Health, Toronto, Ontario, Canada. It was published online on April 1, 2025, in JAMA Network Open.

LIMITATIONS:

This study’s findings were limited by its focus on a single geographic area in a high-income country, potentially affecting generalizability. Some data collected through medical record review were incomplete. The researchers could not assess the impact of iGAS infections in children who were dead on arrival at healthcare facilities, as these cases were legal cases with restricted data sharing.

DISCLOSURES:

This study received support through contracts from the Centers for Disease Control and Prevention and a grant from the Canadian Bacterial Diseases Network (1995-2000). No conflicts of interest were reported.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.