Genomic interrogation of invasive group A Streptococcus (iGAS) epidemiology and COVID-19 impacts in Victoria, Australia: a 6-year retrospective study

Abstract

Background: Invasive group A Streptococcus (iGAS) cases have increased globally in 2022–2023, raising concerns within the medical and public health communities, including in Australia, while this impact is polyclonal in nature the worldwide spread and dominance of M1UK has been particularly concerning. Methods: To investigate these changes and prepare to implement routine genomic surveillance of iGAS for public health purposes, we performed whole genome sequencing (WGS) on iGAS isolates from Victoria, Australia between 2017 and 2022. Genomic analyses were conducted to determine the epidemiology, genetic diversity, and population dynamics of iGAS. Findings: Analysis of 955 confirmed iGAS case..