Undetectable viral load and the decision to engage in unprotected anal intercourse among HIV-positive MSM.

We investigated how often HIV-positive MSM (n = 177) decide to engage in unprotected anal intercourse (UAI) because they have an undetectable viral load (UVL). We found that 20-57% of the UAI acts were related to having UVL, varying by partner type and partner HIV status. Among HIV-concordant partners, consideration of UVL before engaging in UAI was more prevalent with sex buddies (55%) than with casual partners (20%), although marginally significant (p = 0.051). Among HIV-discordant partners, no significant difference was found in the frequency of UVL considerations before engaging in UAI: 40% with sex buddies versus 57% with casual partners. Interestingly, while the decision to engage in UAI based on UVL was frequently discussed with HIV-concordant partners (>91%), it was only discussed with HIV-discordant partners in 13-25% of the UAI cases (according to partner type), suggesting that the decision was mostly unilateral.