Epidemiology of invasive group A streptococcal disease in the North East of Melbourne: insights from surveillance data
DOI:
https://doi.org/10.33321/cdi.2025.49.059Keywords:
invasive group A streptococcal disease, disease epidemiology, surveillance data, iGAS epidemiology, disease trendsAbstract
Invasive group A streptococcal disease (iGAS) was made a notifiable condition in Australia in July 2021 and in Victoria in February 2022. The North Eastern Public Health Unit (NEPHU) in metropolitan Melbourne began managing iGAS cases in May 2023 with little prior knowledge of local epidemiology. Case numbers in NEPHU increased by 139% from 64 in 2022 to 153 in 2023. The incidence rate increased from 3.5 per 100,000 population in 2022 to 8.4 per 100,000 population in 2023. The case fatality rate in NEPHU during this period was 6.9%, with almost half of all deaths among individuals aged 70 years and above. Chronic conditions were commonly reported in the cases’ clinical histories, with 29% of NEPHU cases reporting an underlying illness. International trends of increased incidence of iGAS have been reflected in the NEPHU catchment, albeit with only two years of surveillance data. Monitoring trends in iGAS is an ongoing priority for NEPHU, to better understand disease patterns within the catchment area and to inform public health actions.
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