AMSTERDAM — Researchers at the 22nd International AIDS Conference confirmed Tuesday that the chance of any HIV-positive person with an undetectable viral load transmitting the virus to a sexual partner is scientifically equivalent to zero.
Aidsmap reported that the results were presented during the opening press conference for the event.
From Aidsmap:
Final results from the PARTNER study were presented this morning at a press conference on the opening day of AIDS 2018. Results originally announced in 2014 from the first phase, PARTNER 1, already indicated that “Undetectable equals Untransmittable” (U=U). However, the statistical certainty of this result was not quite as convincing in the case of gay men, or for anal sex, as it was for vaginal sex.
Results from PARTNER 2, the second phase, which only recruited gay couples, were presented today.
The results indicate, in the words of the researchers, “A precise rate of within-couple transmission of zero” for gay men as well as for heterosexuals.
The PARTNER study recruited HIV serodiscordant couples (one partner positive, one negative) at 75 clinical sites in 14 European countries. They tested the HIV-negative partners every six to 12 months for HIV, and tested viral load in the HIV-positive partners. Both partners also completed behavioural surveys. In cases of HIV infection in the negative partners, their HIV was genetically analysed to see if it came from their regular partner.
The study found no transmissions between gay couples where the HIV-positive partner had a viral load under 200 copies/ml – even though there were nearly 77,000 acts of condomless sex between them.
You can read the full statement on Aidsmap.