PARIS, FRANCE – HIV-positive men who are on treatment and have undetectable viral load do not transmit HIV to their partners. This is according to new study – titled “Opposites Attract” – from the Kirby Institute at the University of New South Wales (UNSW) in Australia, and presented at the International Aids Society (IAS) Conference on HIV Science in Paris, France.
For this study, 358 serodiscordant gay male couples (where one has HIV and the other does not) from Thailand, Brazil and Australia were regularly tested from 2012 to 2016. For that period, the researchers recorded 16,889 acts of condomless anal sex, and none of those acts resulted in the transmission of HIV.
“Our research adds to the evidence from a small number of other international studies of heterosexual and homosexual couples and means that we can say, with confidence, that effectively treated HIV blocks transmission in couples of differing HIV status,” said Andrew Grulich, the study’s chief investigator and a professor at the Kirby Institute.
Already, an earlier PARTNER study found that HIV-positive people on effective HIV treatment that fully suppresses their virus cannot transmit their infection through sex.
Both the “Opposites Attract” and the PARTNER studies also found that if the HIV-positive partner is on successful treatment, even having another sexually transmitted infection (STI) does not increase the risk of HIV being transmitted. In “Opposites Attract”, participants had an STI during 6% of anal sex acts; while in the PARTNER study, 17.5% of participants had an STI at some point in the study.
Sexual positions also did not matter even though when viral load is not suppressed, transmission is 10-20 times more likely if the HIV-positive partner is the insertive one (i.e. “top”). In “Opposites Attract”, the HIV-positive partner was “top” over a third of the time.
Three men actually became infected with HIV during the “Opposites Attract” study. However, genetic analysis showed that these infections came from a partner outside the main relationship who was not virally suppressed.
The results of “Opposites Attract” strengthen the “U=U” (Undetectable=Untransmittable) campaign of the Prevention Access Campaign, whose consensus statement was signed by the International AIDS Society (IAS) and NAM, organizers of the conference in Paris.
For Kevin Robert Frost, CEO of amfAR, one of the organizations that funded the study, these results are “extremely encouraging and underscore the need to get people tested and onto treatment immediately if they are HIV positive,” he said in a statement released to the media. “This important breakthrough underscores yet again how investments in HIV research yield invaluable dividends in the global response to HIV.”
Bavinton B et al. (presenter Grulich A). HIV treatment prevents HIV transmission in male serodiscordant couples in Australia, Thailand and Brazil. 9th International AIDS Society Conference on HIV Science, Paris, abstract no TUAC0506LB, July 2017.