1. Melbourne Sexual Health Centre, 580 Swanston Street, Carlton 3053, Victoria, Australia
2. School of Population Health, University of Melbourne, Victoria, Australia
3. Department of Epidemiology and Preventive Medicine, Monash University, Victoria, Australia
4. National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, Australia
5. Sydney Sexual Health Centre, Sydney Hospital, Sydney, Australia
6. Canberra Sexual Health Centre, The Canberra Hospital, Canberra, Australia