A new analysis of data regarding mixed HIV status heterosexual couples suggests that, although rare, the transmission of HIV while taking antiretrovirals (ARVs) may still take place, aidsmap reports. Publishing their findings in Clinical Infectious Diseases, French researchers conducted a literature review of studies of 1,672 heterosexual discordant couples in which the partner with HIV was taking ARVs.

The investigators found four cases of one partner transmitting to another during 2,773 person-years. The transmissions were proven through genetic analysis to have taken place within the couples. The various studies found that between 70 percent of the groups of HIV-positive partners were virally suppressed. Seventeen percent of the sex acts did not involve condoms.

The researchers calculated that the highest risk of transmitting HIV through condomless heterosexual intercourse was either 8.7 or 13 per 100,000 acts, depending on whether the HIV-positive partner had been taking ARVs for greater than or less than six months. (Granted, the actual risk may be much lower.) This means that if a couple were having sex an average of six times a month, after 10 years and 720 acts of intercourse, there would be a 1.85 percent or 3.7 percent risk of transmission.

To read the aidsmap story, click here.

To read the study abstract, click here.