Scientists have revealed that after two years of study, a group of HIV positive gay men with an undetectable viral load (thanks to antiretroviral treatment) did not transmit the virus to their partners.
While previous studies had found similar results for heterosexual couples, the new research included significant numbers of gay couples for the first time.
For the study, scientists recruited 1110 European couples – almost 40% of whom were gay – in which the partners had differing HIV statuses.
They found after two years that none of the HIV positive partners who were on successful antiretroviral therapy (ART) – with a viral load under 200 copies/ml – had transmitted the virus to their HIV negative partners, whether by anal or vaginal sex.
According to Aidsmap, the couples who participated were chosen in part because they did not always use condoms. Among the gay couples there were an estimated 16,400 sexual contacts, none of which resulted in HIV transmission.
The preliminary results of the PARTNER study were released at the 2014 Conference on Retroviruses and Opportunistic Infections (CROI) in Boston, Massachusetts.
While statistically the maximum chances of infection through anal sex by a partner whose viral load is undetectable was estimated at 1% a year, researchers said that in reality this is likely to be closer to zero, or even zero.
The research adds more credibility to the strategy of treatment of HIV positive gay, bisexual or men who have sex with men as a means to prevent infection.
TAC founder Zackie Achmat commented on the study on Facebook. “Do we need more evidence that treatment is not only effective in saving lives but also as prevention?” he asked, adding, “Get tested! Get treated!”
The PARTNER study is not yet complete and is still recruiting gay male couples. Final full results are set to be released in 2017.