Implications for HIV prevention programs from a serobehavioural survey of men who have sex with men in Vancouver, British Columbia: the ManCount study.

BACKGROUND: We examined HIV prevalence, awareness of HIV serostatus and HIV risk behaviour among a sample of men who have sex with men (MSM) in Vancouver.
METHODS: MSM > or = 18 years were recruited from August 2008 to February 2009 through community venues. Participants completed a questionnaire and provided a dried blood spot (DBS) for HIV and other STI testing. We performed descriptive statistics and bivariate analyses of key explanatory variables.
RESULTS: A total of 1,169 participants completed questionnaires; of these, 1,138 (97.3%) provided DBS specimens suitable for testing. The median age was 33 years (IQR 26-44). A total of 206 (18%) were HIV-positive by DBS, of whom 86% were aware they were positive. HIV seropositivity increased from 7.1% in those < 30 years of age to 19% in those 30-44 years and 34% among those > or = 45 years (p < 0.001 for test of trend). Of the 933 who self-reported as HIV-negative or unknown, 28 (3.0%) tested HIV-positive. Among those not tested for HIV in the previous 2 years, the reasons for not testing differed between participants with undiagnosed HIV infection and those who were HIV-negative. A total of 62% of study participants who self-reported as HIV-negative reported using a condom the last time they had anal sex. The use of risk-reduction measures was reported by 91.1% of all study participants (72% if excluding consistent condom use).
CONCLUSION: The majority of MSM in Vancouver have adopted behaviours that reduce their HIV-related risk. However, prevention programs must continue to promote condom use, increase HIV testing, and better inform MSM of the value and limitations of other risk-reduction strategies.