Community-associated methicillin-resistant Staphylococcus aureus in the Kimberley region of Western Australia, epidemiology and burden on hospitals.

This study presents surveillance data from 1 July 2003 to 30 June 2023 for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) notified in the Kimberley region of Western Australia (WA) and describes the region's changing CA-MRSA epidemiology over this period. A subset of CA-MRSA notifications from 1 July 2003 to 30 June 2015 were linked to inpatient and emergency department records. Episodes of care (EOC) during which a positive CA-MRSA specimen was collected within the first 48 hours of admission and emergency presentations (EP) during which a positive CA-MRSA specimen was collected on the same day as presentation were selected and analysed further. Notification rates of CA-MRSA in the Kimberley region of WA increased from 250 cases per 100,000 populations in 2003/2004 to 3,625 cases per 100,000 in 2022/2023, peaking at 6,255 cases per 100,000 in 2016/2017. Since 2010, there has been an increase in notifications of Panton-Valentine leucocidin positive (PVL⁺) CA-MRSA, predominantly due to the 'Queensland Clone'. PVL⁺ CA-MRSA infections disproportionately affect younger, Aboriginal people and are associated with an increasing burden on hospital services, particularly emergency departments. It is unclear from this study if PVL⁺ MRSA are associated with more severe skin and soft-tissue infections, and further investigation is needed.