Researchers kept up with 358 gay male couples over four years. So far, not a single HIV positive partner has transmitted the virus. - From NBC News
From 2012 to 2016, the study regularly checked in with 358 serodiscordant gay male couples (where one has HIV and the other does not) from Thailand, Brazil and Australia.
On Tuesday, the findings of the study, titled "Opposites Attract," were presented at the International Aids Society (IAS) Conference on HIV Science in Paris.
"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," Andrew Grulich, the study's chief investigator and a professor at the Kirby Institute, said in a statement.
Kevin Robert Frost, the CEO of amfAR, one of the organizations that funded the study, found the results encouraging.
"As HIV continues to disproportionately affect gay men and other men who have sex with men worldwide, the results of this study are extremely encouraging and underscore the need to get people tested and onto treatment immediately if they are HIV positive," Frost said in a statement.