Ongoing research found zero linked HIV transmissions cases after mixed-HIV status couples had sex 58,000 times without condoms.
Heterosexual and gay couples, of whom one was HIV positive and took antiretroviral (ARVs) showed zero cases of infections after having sex without condoms; the study highlighted the power of ARVs ability to curtail the spread of the virus.
The Partner study (phase 2) was conducted at 75 clinical sites in 14 European countries. The new analysis, published in the Journal of the American Medical Association, examines data from September 2010 to May 2014, focusing on 888 couples, 62 percent of which were heterosexual couples and 38 percent of which were gay male couples. Between them, the couples provided 1,238 cumulative years of follow-up, or a median 1.3 years. The analysis focused on periods when the HIV-positive partner had a viral load below 200 and when the couples reported condomless sex.
When starting the study, the couples reported they had engaged in condomless sex for a median two years. A total of 108 (33 percent) of the HIV-negative gay men reported condomless sex outside their primary partnership, as did 21 (4 percent) of the HIV-negative heterosexuals.
During the study follow-up period, the couples reported a median 37 incidents of condomless sex per year, including a cumulative 22,000 such acts among the gay couples and 36,000 among the heterosexual ones.
Eleven of the HIV-negative partners contracted the virus during the follow-up period, including 10 gay and one heterosexual individuals; eight of this group reported sex outside their partnership.
However, genetic analyses showed that none of these transmissions apparently occurred within those primary partnerships. In other words, there were no HIV transmissions between partners when the HIV-positive individual had a viral load below 200.
In other words, zero transmissions from over 58,000 individual times that people had sex without condoms.
Simon Collins of HIV-I Base stated that “this [study] provides the strongest estimate of actual risk of HIV transmission when an HIV positive person has undetectable viral load – and that this risk is effectively zero.
“The results provide a dataset to question whether transmission with an undetectable viral load is actually possible. They should help normalise HIV and challenge stigma and discrimination.”
THT Medical Director, Dr Michael Brady commented: “We can now say with confidence that if you are taking HIV medication as prescribed, and have had an undetectable viral load for over six months, you cannot pass HIV onto your partner, with or without a condom
The results challenge criminalisation laws that in many countries, including Scotland, continue to criminalise HIV positive people on assumptions of them being a risk which this study results clearly disprove, even when condoms are used and viral load is undetectable.
The researchers cannot at this point rule out that there is a risk of HIV transmission with such a low viral load, particularly for anal sex and when considering how risk may accumulate over a period of several years. Greater follow-up is needed.
Study author stated: “Although these results cannot directly provide an answer to the question of whether it is safe for serodifferent [mixed-HIV status] couples to practice condomless sex, this study provides informative data (especially for heterosexuals) for couples to base their personal acceptability of risk on.”
In an accompanying editorial, Eric S. Daar, MD, and Katya Corado, MD, of the Harbor-University of California, Los Angeles, Medical Center, wrote: “For individuals who want to routinely or intermittently not use condoms with an HIV-infected partner, clinicians can indicate that the risk of HIV transmission appears small in the setting of continued viral suppression, emphasising that the duration the HIV-infected partner needs to be virologically suppressed before achieving optimal protection is unknown, although appears to be for at least 6 months, based on the best available data.”