Written by Kimiko Dunbar
Spoon Feed
Invasive group A strep infections have increased since 2022. The most severe, life-threatening infections are associated with the emm 1 subtype and viral co-infection.
Be wary of the emm1
Invasive group A strep infections (iGAS) are increasing and remain a leading cause of pediatric morbidity and mortality. Research is limited on risk factors for the most severe infections. This 10-year retrospective national cohort study in Scotland examined children ≤15 years with life-threatening iGAS infection requiring pediatric intensive care or resulting in death (n=82). The mean annual PICU admission and mortality rates were 0.69 and 0.22 per 100,000, respectively. A sharp 2022-2023 case rise (17 admissions, 4 deaths) aligned with increased emm1 bacterial subtype prevalence and viral co-infections, notably HMPV. This study has some important limitations. Authors intentionally only included the most severe cases, which likely misses patients with severe disease such as an empyema not requiring PICU admission or sepsis without ventilatory support. Further, the population only included cases in Scotland, a unique environment (there are only 2 PICUs Scotland, for example), so application to other countries could be limited.
How does this change my practice?
I’m certainly seeing a lot more iGAS infections, far more than described in this article given the stringent inclusion criteria. Previously covered here and here, this study echoes prior research on the rise of invasive infections. I’d be more wary of the patients infected with the emm1 subtype, although specific subtype testing may not be available everywhere. While viral co-infection was also associated with severe disease, it is exceedingly common in pediatric patients presenting with a variety of complaints. I’d be interested to know more about the rates of co-infection of those with less severe disease.
Source
National 10-year Cohort Study of Life-threatening Invasive Group A Streptococcal Infection in Children, 2013-2023. Pediatr Infect Dis J. 2025 May 12. doi: 10.1097/INF.0000000000004855. Epub ahead of print. PMID: 40359236
