Antimicrobial resistance in northern Australia: the HOTspots surveillance and response program annual epidemiology report 2022.

Background: The HOTspots surveillance and response program monitors antimicrobial resistance (AMR) in selected bacterial pathogens across three jurisdictions in northern Australia. In 2022, the program collected data from 164 community healthcare clinics and 50 hospitals to assess AMR trends and geographic variations.

Methods: Data on resistance rates for methicillin-resistant Staphylococcus aureus (MRSA) and for Escherichia coli (E. coli) were analysed. Geographic regions were compared to identify variations in AMR across the Northern Territory, northern Western Australia and northern Queensland. Resistance rates were compared between community clinics and hospitals.

Findings: In 2022, there were 56,003 clinical isolates submitted to HOTspots. Geographic variation was evident in S. aureus methicillin resistance, with MRSA accounting for 14.4% of S. aureus isolates in the east, 53.1% in central northern Australia and 46.3% in western northern Australia. Clindamycin-resistant MRSA was highest in the Northern Territory (21.7%) compared to Western Australia (16.1%) and Queensland (5.9%), limiting treatment options for community-acquired MRSA. Ceftriaxone-resistant E. coli also varied geographically, with resistance rates ranging from 3.9% in the east to 23.4% in central and 10.1% in the west. High rates of ceftriaxone resistance were observed in both community clinics (10.6%) and hospitals (16.3%). Nitrofurantoin-resistant E. coli remained low (0.2%) and stable over the past five years.

Interpretation: HOTspots data are critical for informing local antibiotic guidelines and aiding clinical decision-making. This detailed surveillance captures geographic and healthcare-setting-specific variations in AMR, which can improve regional treatment strategies across northern Australia, with a focus on the Northern Territory, which had previously lacked comprehensive surveillance.