Poster Presentation Lancefield International Symposium for Streptococci and Streptococcal Diseases 2025

The rise of invasive group A streptococcal infection in a quaternary Australian hospital (#46)

Adrian Alexander 1 , Ashmitha Thomas 1 , Andrew Stewardson 1 , Adam Jenney 1 2
  1. Department of Infectious Diseases, The Alfred Hospital, Melbourne, VIC, Australia
  2. Microbiology Unit, The Alfred Hospital, Melbourne, Australia

Background:

As seen globally, there was a notably spike in Group A Streptococcal (GAS) infections diagnosed from 2022 in our hospital, a metropolitan quaternary centre in Melbourne, Australia.

Methods:

Between 1 May 2022 and 30 April 2024, we identified all GAS infections identified by culture. 

Results:

Of 342 individuals  with GAS cultured, 82 (24.0%) had proven or probable invasive GAS (iGAS). Two-thirds (66.7%) were male and 12 (14.6%) diabetic. Greater than a quarter (29.3%) identified as people who inject drugs.

Skin and soft tissue infection (SSTI) was the commonest disease process seen, in 50 (70.5%). Of these, 19 were diagnosed as necrotising SSTI (of which 4 (21.1 %) were also bacteraemic), and 31 were non-necrotising SSTIs, and of these 18 (58.1%) were bacteraemic. People who inject drugs seemed to be over represented in the SSTI group but when the proportion (50%) was compared to the group not identifying a people who inject drugs (32%) the difference did not reach significance (p<0.07).

The overall median length of hospital stay was 10.4 days (range 0.9 – 88.4). ICU admission was required for 35 (42.7%) and 53 (64.6%) needed surgical intervention. Intravenous immunoglobulin was administered in 21 (25.6%) and the 28-day mortality for iGAS was 4.9%.

Conclusion:

Increased GAS diagnoses in 2022-4 exceeded the Group C/G diagnoses, a reversal of the previous 2 years. This notable spike included a large number of iGAS infections requiring considerable resources to treat them (ICU admissions and surgeries) though with a surprisingly low mortality.