For couples in which one partner has HIV, preventing the infection in the other partner has been successfully achieved by consistently following antiretroviral pre-exposure prohpylaxis (PrEP), according to a recent study published in PLOS Medicine.
The study, led by Dr. Jessica Haberer from Harvard Medical School, is the first to effectively monitor participants' adherence to preventative treatment and show successful outcomes as a result.
Previous studies have shown inconsistent protection against HIV efficacy, with success rates ranging from 0-75%. This discrepancy is likely due to differences in how well the participants adhered to taking the antiretroviral drugs.
But this recent study saw researchers using unannounced home-based pill counts and electronic pill bottle monitoring to actively monitor the participants' adherance.
In total, 1,147 HIV-uninfected participants who were enrolled in three Ugandan sites of the Partners PrEP Study were followed. The median age was 34 years, 53% were male and the average partnership length was 8.5 years.
Every participant had an HIV-positive partner, and if unannounced pill count adherence was below 80%, they would receive counseling on how and why to continue taking the pills.
In this particular study, which only followed heterosexual couples, adherance was very high - at 99% in unannounced pill counts and 97% via electronic monitoring - and resulted in only 14 participants becoming HIV-positive. All of these individuals were on a placebo drug.
"These data provide further support that PrEP is highly efficacious at preventing HIV acquisition when it is taken," say the authors.
They note that over 2.5 million people worldwide are infected with HIV each year.
According to the US Department of Health & Human Services, in the US alone, 1 million people are living with HIV, and 1 in 5 are unaware of their infection. Additionally, every 9.5 minutes, someone in the US is infected with HIV.
Successfully preventing the spread of HIV has been a major focus for researchers, but until now, the efficacy of PrEP in preventing spread of the infection has not been accurately documented, due to the varying adherence levels within study participants.
Moving forward, the authors say that "proper support and assessment of adherence will be critical for determining efficacy of PrEP outside of clinical trials."
"This data will be important for guiding ethical decisions about resource allocation for both prevention and treatment of HIV."
Dr. Jessica Haberer told Medical News Today:
"This study gives us confidence that PrEP is highly effective in preventing HIV acquisition, as long as it is taken as prescribed. Good adherence, however, is challenging, and PrEP may not be right for everyone.
For instance, it may make sense for serodiscordant couples in which the HIV-infected partner has not yet started effective antiretroviral therapy, but it may not be a good choice for people who are not very sexually active or who do not perceive themselves to be at risk for HIV."
She said that future research should try to determine who is a good candidate for PrEP and how to best support them.
Medical News Today recently reported that the US Food and Drug Administration (FDA) approved a rapid HIV test.