A long-term clinical study conducted over a seven-year period regarding the transmission of HIV by people receiving anti-retroviral therapy (ART) was published in the Lancet earlier this month and has shown some remarkable findings. The PARTNER study, as it was called, was a prospective observational study done at 75 sites in 14 European countries. PARTNER1, which was the first phase of the study, was done on both heterosexual and gay couples with serodifferent partners (where one partner is HIV-positive and on ART and the other is HIV-negative) who indulged in unprotected sex.
PARTNER2 was the second part of the study, and it recruited and followed gay couples only up to April 30th, 2018. Study visits included testing for HIV, answering questionnaires on sexual behaviour and testing the viral load in the HIV positive partner. If a previously HIV-negative partner was found to be HIV-positive at a follow-up visit, the viral load was measured in him as well.
Of the 972 gay couples enrolled between Sept 15, 2010, and July 31, 2017, the study showed an HIV transmission rate of 0%, despite report of condomless sex between the partners. 15 new HIV positive cases were found during the study but none were in-couple transmissions themselves. The results have provided a level of evidence in line with similar findings in heterosexual couples and suggest that unprotected sex among homosexual couples with the affected partner on ART has the same risk of transmission as in heterosexual couples – effectively zero. The idea of undetectable HIV being equal to un-transmittable HIV was reinforced by this study.
This study represents a huge step forward in treatment of HIV and can make a huge difference in the lives of those affected by the disease. While there is still a long way to go in terms of awareness among the general population, the study can help expunge some of the fears that people have when it comes to unprotected sex with people suffering from HIV. The stigma that is associated with the disease tends to overshadow the fact that there is an effective treatment for it and that unlike in the past, HIV does not mean a death sentence anymore.
Importantly, the implications of this study are that it could be possible to limit the current prevalence of HIV within the general population and help in keeping the disease confined to this current generation, based off of the data that it has generated. However, the study was done in a limited population when compared to the global burden of the disease and thus, the extrapolation of this data, while will most likely lead to similar results, is something that should be approached with caution. Awareness is also a major issue that needs to be tackled because for a study like this to gain widespread foothold in the general society, the layman must have the knowledge of it and the understanding to accept the results of the study without prejudice – something that might be easier said than done.