Trends in gonorrhoea testing and incidence among gay and bisexual men in Australia during PrEP implementation: an analysis of surveillance data (2012–2023)

Objectives Gonorrhoea incidence is increasing globally, with gay and bisexual men (GBM) over-represented in notifications. Changes in behaviour, sexual networks and screening practices associated with HIV pre-exposure prophylaxis (PrEP) uptake and treatment-as-prevention may influence gonorrhoea transmission. We describe trends in gonorrhoea testing and incidence among GBM over 12 years spanning PrEP implementation in Australia. Methods We conducted a retrospective study using surveillance data from 67 sexual health and general practice clinics between 1 January 2012 and 31 December 2023. For testing analyses, we included GBM with ≥1 visit and calculated annual test uptake (proportion of attendees tested at least once). For incidence analyses, we included GBM with ≥2 tests and calculated annual gonorrhoea incidence per 100 person-years (py). Test uptake and incidence were stratified by HIV status and PrEP use (ever vs never prescribed PrEP). Poisson regression explored factors associated with incident gonorrhoea, adjusted for calendar year and age. Results A total of 193 053 GBM attended a clinic during the study period, of which 176 244 (91.3%) had ≥1 test. Annual test uptake increased from 58.7% in 2012 to 75.2% in 2023, largely driven by increased testing among ever-PrEP-users. Among 119 741 GBM in incidence analyses, there were 61 896 gonorrhoea infections over 542 949 py (incidence rate=11.4/100 py). From 2012 to 2023, incidence among HIV-negative ever-PrEP users increased from 6.2 to 19.6/100 py (p<0.001), and among GBM with HIV increased from 8.6 to 18.8/100 py (p<0.001). GBM with recurrent infections (n=13 620; 11.4%) accounted for 69.1% of all diagnoses. Ever being prescribed PrEP (adjusted incidence rate ratio (aIRR)=2.40, 95% CI: 2.35 to 2.45) and living with HIV (aIRR=3.05, 95% CI: 2.97 to 3.13) were associated with incident gonorrhoea. Conclusions In this large cohort of GBM, gonorrhoea incidence significantly increased during PrEP implementation, although incidence was already rising before large-scale PrEP roll-out in 2016. GBM with HIV, PrEP users or those previously diagnosed with gonorrhoea should be prioritised for testing and prevention strategies.