The news comes amid a raft of positive announcements made around HIV research during the Conference on Retroviruses and Opportunistic Infections (CROI) in Boston last week.
The Partner study looked at 282 serodiscordant gay male couples (where one partner is HIV-positive and one is HIV-negative) where the HIV-positive man was on effective antiretroviral treatment with an undetectable viral load and the couple were having unprotected anal sex. The study reported no HIV transmissions in these couples over the course of a year.
These results provide encouraging evidence for the “treatment as prevention” approach to HIV, which focuses on encouraging early diagnosis and treatment of HIV as a way to reduce new infections. People living with HIV on effective treatment and with a low viral load have a significantly reduced chance of passing the virus on, and increased testing and early diagnosis can lead to changes in sexual behaviour to further reduce that chance.