ASydney Sexual Health Centre, Sexual Health and Bloodborne Viruses, Population and Community Health, South Eastern Sydney Local Health District, Sydney, NSW, Australia.

BThe Kirby Institute, Kensington, NSW, Australia.

CSchool of Population Health and Community Medicine, University of New South Wales, Kensington, NSW, Australia.

DCentre for Population Health, Blood Borne Viruses and STI Program, NSW Health, St Leonards, NSW, Australia.

EPresent address: Cairns Sexual Health Service, Cairns and Hinterland Hospital and Health Service, 381 Sheridan Street, Cairns North, Qld4868, Australia.