Declining prevalence of undiagnosed HIV in Melbourne: results from community-based bio-behavioural studies of gay and bisexual men

OBJECTIVE: To measure changes in undiagnosed HIV among gay and bisexual men (GBM) in Melbourne. METHODS: Undiagnosed HIV was compared between GBM recruited anonymously in 2008 in gay venues only and GBM anonymously or confidentially (results delivery) recruited in 2014 at gay venues and a community festival. Surveys were completed and oral fluid specimens collected for HIV testing; positive tests among GBM reporting being HIV-negative or unknown/untested were classified as undiagnosed. Tests of proportions compared serological prevalence, undiagnosed prevalence and participant characteristics. RESULTS: HIV prevalence was 9.5% and 7.1% among 639 and 993 GBM recruited in 2008 and 2014, respectively; undiagnosed prevalence declined significantly from 31.1% to 7.1% (p