Australian Gonococcal Surveillance Programme Annual Report, 2016

Abstract

The Australian Gonococcal Surveillance Programme (AGSP) has continuously monitored antimicrobial resistance in clinical isolates of Neisseria gonorrhoeae from all states and territories since 1981. In 2016, there were 6,378 clinical isolates of gonococci from public and private sector sources tested for in vitro antimicrobial susceptibility by standardised methods. Current treatment recommendations for the majority of Australia is a dual therapeutic strategy of ceftriaxone and azithromycin. Decreased susceptibility to ceftriaxone (Minimum Inhibitory Concentration or MIC value 0.06-0.125 mg/L) was found nationally in 1.7% of isolates, similar to that reported in the AGSP Annual Report 2015 (1.8%). The highest proportions were reported from Queensland and Tasmania (3.7% and 3.6% respectively). Resistance to azithromycin (MIC value ≥1.0 mg/L) was found nationally in 5.0% of isolates, double the proportion reported in 2015. The highest proportions were reported from South Australia (19.5%), Tasmania (14.3%) and urban Western Australia (7.6%). High level resistance to azithromycin (MIC value ≥256 mg/L) was again reported in 5 strains. Nationally in 2016, 4 from Victoria and 1 in South Australia. There was no reported azithromycin resistance in remote Northern Territory.

The proportion of strains resistant to penicillin in urban Australia ranged from 10.7% in the Australian Capital Territory to 41.8% in New South Wales. In rural and remote Northern Territory penicillin resistance rates remain low (3.0%). In remote Western Australia penicillin resistance rates have increased (5.3%) compared to the previous years, however, there were relatively low numbers of strains available for isolate based testing. To address this and to monitor resistance and inform treatment guidelines, widespread molecular testing for penicillin resistance in Western Australia is in place, and these data are included in the AGSP.

The proportion of strains resistant to ciprofloxacin in urban Australia ranged from 16.1% in the Australian Capital Territory to 41% in South Australia. Ciprofloxacin resistance rates remain comparatively low in remote areas of the Northern Territory (3.0%) and remote areas of Western Australia (4.5%).