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.
