Clinical presentation and recent health care contacts in patients with invasive group a streptococcal infection, Western Sweden 2020–2024

Cases of invasive group A streptococcal infections (iGAS) increased dramatically in Sweden and other high-income countries during 2023 and 2024. Changing epidemiology and stricter antibiotic stewardship policies are suggested to contribute to this increase.
To describe the clinical presentation and previous health care contacts among cases of iGAS infection over a 5-year period.
A retrospective cohort study of iGAS patients treated at Sahlgrenska University Hospital, Gothenburg, Sweden, between January 2020 and July 2024, identified through the hospital’s Clinical Microbiology Laboratory Information System. Data was collected through detailed medical record review by the study team.
In total, 190 patients with iGAS were included, with the majority (70%, n = 133) treated during 2023–2024. The median age was 53 years (range 1–97) and 51% had no chronic comorbidities. The most common clinical manifestations were erysipelas (22%, n = 42), bacteraemia without focus (21%, n = 39), lower respiratory tract infection (15%, n = 29) and necrotising soft tissue infection (13%, n = 25). Thirty-day mortality was 13% (25/190) with the highest mortality risk for patients with bacteraemia without focus. Relevant health care contacts within 30 days before hospitalisation could be analysed in 167 patientsand was documented in 27% (n = 45) of these cases, most commonly due to a wound (10%, n = 17) or sore throat (9%, n = 15).
The post-pandemic increase in iGAS affected all age groups. Soft tissue infections remained the dominant type of infection, with erysipelas accounting for around one in four episodes. The iGAS patients had frequently sought care with related complaints shortly before hospitalisation.