Comfort Relying on HIV Pre-exposure Prophylaxis and Treatment as Prevention for Condomless Sex: Results of an Online Survey of Australian Gay and Bisexual Men.

HIV-negative and untested gay and bisexual men from Victoria, Australia (n = 771) were surveyed during August-September 2016 about their comfort having condomless sex with casual male partners in scenarios in which pre-exposure prophylaxis (PrEP) or treatment as prevention were used. Men not using PrEP were most comfortable with the idea of condomless sex with HIV-negative partners (31%), followed by partners using PrEP (23%). PrEP users were more comfortable with the idea of condomless sex with these partner types (64 and 72%, respectively). Very few men not taking PrEP were comfortable with condomless sex with HIV-positive partners (3%), even with undetectable viral loads (6%). PrEP users were more comfortable with condomless sex with HIV-positive partners (29%), and those with undetectable viral loads (48%). Being on PrEP, having recent condomless sex with casual partners or a HIV-positive regular partner were independently associated with comfort having condomless sex.