In 2011, the HPTN 052 study found that successful antiretroviral (ARV) use can reduce the likelihood of HIV transmission among heterosexual serodiscordant couples by 96 percent. A new Chinese analysis of data on nearly 39,000 serodiscordant straight couples, culled from the national records spanning 2003 to 2011, found that ARVs lowered the transmission risk by 26 percent in the first year after beginning therapy.

At first glance, the comparison seems to cast doubt on the treatment-as-prevention [TasP] model. But Sten H. Vermund, MD, PhD, director of the Institute for Global Health at Vanderbilt University Medical Center in Nashville, Tennessee, thinks the Chinese study “suggests a confirmation in a real-world circumstance of the basic concept of TasP. It also cautions us about the gap between an idealized, optimized protective effect.”

Indeed, the study results question how variables such as low adherence to meds, which can lead to higher viral loads, may raise HIV-positive partners’ infectiousness and lessen the protective effects of ARVs.  

Unfortunately, the Chinese study lacked information about viral load, med adherence, or the potential that needle sharing was the source of transmission.

For more information on TasP, click here.