A significant proportion of Montreal's MASM, some of whom are at risk of contracting HBV through sexual and parenteral transmission, have not been vaccinated for HBV. Men who have affective and sexual relations with men should be educated about the risk of HBV transmission and the seriousness of the disease.

Our data indicate that HIV-positive gay and bisexual men are more likely to be living in unstable conditions and to report more risky sexual and substance use behaviors than HIV-negative men.

Young Omega participants do not have more risky behaviors than older participants. Some predictors of recent risk behaviors with casual partners were different between the two groups. Prevention programs should be adapted consequently.

No abstract

There was a nonnegligible and consistent increase in UAI among Omega participants, between 1997 and 2003. Continuous trend analysis is important because it allows us to closely follow UAI and to implement intervention strategies that may help to stop or reduce the present trend.