Antiretroviral therapy dramatically cuts the risk of HIV transmissions between serodiscordant heterosexual couples, researchers report in the September 1 edition of the Journal of Acquired Immune Deficiency Syndromes. A study of 393 couples conducted between 1991 and 2003 shows that the HIV prevalence rate among the initially HIV-negative partners fell from 10% before triple-drug therapy became available to just 2% in the highly active antiretroviral therapy era, and all of those infections occurred on early, less-potent regimens. The researchers say low viral levels of HIV in the body achieved through successful antiretroviral treatment decrease the infectiousness of the positive partner.
Researchers raise a flag of caution, though, that although their study results indicate that treatment can reduce the risk of HIV transmission to a seronegative heterosexual partner, even the slightest increase in taking sexual risks could cancel out this reduction in transmission. 'The main preventive measure for HIV sexual transmission,' they stress, 'remains the avoidance of risky sexual practices.'