In a recent study named Opposites Attract, which was unveiled at International AIDS Society Conference on HIV science in Paris this past week, a pretty astonishing revelation was found in regards to what the medical field refers to as ‘undetectable‘ in HIV-positive patients. The term represents the viral load, or the amount of active virus cells, in the patient’s body. It means these levels are low enough that modern medical tests cannot detect the HIV virus. Until now, there was no data to support that a patient with such a low number of active cells would be unable to pass the virus along to their sexual partners. After this study, that has changed.

The study recruited 343 same-sex couples across Australia, Thailand and Brazil where one partner is HIV-negative and the other is HIV-positive, which is also known as a serodiscordant couple. In each couple, the HIV-positive partner was on successful HIV treatment, meaning they had an ‘undetectable load’.

The study that could change how we see HIV

While studying each couple and their reported data, it was found that despite 16,889 counts of unprotected sex tallied between all of the couples, not a single case of HIV transmission occurred.


The evidence from Opposites Attract supports another study from 2016 by PARTNER, which focused on HIV-positive patients who were taking certain medications that were being used to suppress the virus down to an undetectable level. Per the 2016 study: “Between September 2010 and May 2014 the PARTNER study prospectively enrolled 1166 serodifferent couples at 75 clinical sites in 14 European countries. Entry criteria included the positive partner having an undetectable viral load on ART and that the couples were not always using condoms when they had sex.”

In the PARTNER study, there were 11 people in the case study that became infected with HIV, but the transmission could not be directly linked to the partners they had within the case. This is mostly due to there being several different strains of the HIV virus and the fact that the infected person’s strain did not match that of their undetectable case partner.

The Opposites Attract study took the findings from PARTNER and refocused on dedicated monogamous couples. By setting more strict rules, the study found that it is quite possible to refrain from transmitting the virus if you choose to not be as promiscuous.

Undetectable’s new meaning

Thanks to the Opposites Attract study, the stigma around HIV-positive patients could soon be dissolved. The National AIDS Manual, more commonly known as NAM, has been a thorough supporter of Opposites Attract. “For many years, those of us with diagnosed HIV have had to live with the idea that our bodies are dangerous. This has had a profound emotional impact on many people,” said NAM’s Executive Director Matthew Hodson. “It is wonderful to consider what this news can mean to people with HIV who are too scared to have sex in case they pass their virus on, or to those in relationships with HIV-positive people whose sexual pleasure has been hampered by fear.”

By helping extinguish such stigmas around HIV, groups like PARTNER and NAM are helping pave a much smoother path forward for those of us living with the virus everyday.