Researchers in China have shown for the first time that HIV transmission rates could be reduced markedly by providing antiretroviral therapy (ART) for the HIV-positive partners in serodiscordant couples (where only one partner is HIV-positive).
After the randomised controlled trial HPTN 052 showed in 2011 that ART treatment for the HIV-positive partner in a serodiscordant couple reduces sexual transmission of HIV, the WHO too has issued guidelines recommending that all HIV-positive partners in serodiscordant couples should be offered ART. However, until now, the real-world efficacy of this recommendation has never been tested.
A group of researchers led by Professor Yiming Shao, at the Chinese Centre for Disease Control and Prevention in Beijing, examined data from China’s national HIV and epidemiology and treatment databases on over 38,000 serodiscordant couples. Of these, 24,057 couples had received ART at the start of the study period, while 14,805 had not. Couples were followed for up to nine years (2003 – 2011). The scientists found that the rate of HIV transmission to the uninfected partner in the group that had received treatment was significantly lower than in the group that received no treatment, with ART for the HIV-positive partner conveying an overall 26% relative reduction in the risk of HIV transmission, compared to those without treatment.
“This is the first time that ART for serodiscordant couples has been shown to have an effect on reducing HIV transmission rates in a real-world setting, vindicating the results of earlier trials, and demonstrating that this approach to reducing HIV transmission is feasible and effective in practice,” said the Lancet.
However, the authors noticed that the treatment as prevention was not effective when HIV-positive partners were injecting drugs or had very high CD4 cell counts (1). Writing in a linked Comment, Professor Sten Vermund, at Vanderbilt University in Nashville, Tennessee, USA, describes the results as “encouraging”, but adds that, “For further insights, we must rely on research that is still in progress.”