Does providing antiretroviral therapy to a person with human immunodeficiency virus (HIV) infection prevent transmission of HIV to a sex partner without infection?
Rates of HIV transmission are at least three times lower in HIV-discordant couples in which the partner with infection is receiving antiretroviral therapy, compared with HIV-discordant couples in which the partner with infection is not receiving therapy. Among HIV-discordant couples in which the infected partner has a CD4 cell count of 350 to 550 per mm3 (0.35 to 0.55 × 109 per L), evidence suggests that treating the infected partner with antiretroviral drugs confers a statistically significant decrease in the risk of transmission to the uninfected partner. (Strength of Recommendation: A, based on consistent, good-quality patient-oriented evidence.)
The World Health Organization recommends antiretroviral therapy for persons with HIV infection and a CD4 cell count of 350 per mm3 or less.1 Higher HIV viral loads are associated with increased risk of transmission. Providing antiretroviral therapy in pregnancy has been shown to reduce the risk of mother-to-child transmission.2 Observational data, ecologic studies, and ecologic models suggest that providing antiretroviral therapy to persons with HIV infection whose sex partner is not infected might decrease the risk of transmission to the uninfected partner. Because antiretroviral therapy is recommended for those with a CD4 cell count of 350 per mm3 or less, this Cochrane review examined whether providing antiretroviral therapy to those with a CD4 cell count greater than 350 per mm3 could reduce the risk of HIV transmission among HIV-discordant couples.
The review included one randomized controlled trial and seven observational cohort studies. These studies included heterosexual and homosexual male HIV-discordant couples. Only studies that included a treatment group and a control group were included.
The randomized controlled, multicenter trial enrolled 1,763 HIV-discordant heterosexual and male homosexual couples in sub-Saharan Africa, Asia, Latin America, and the United States.3 All patients with HIV infection had a CD4 cell count of 350 to 550 per mm3 at baseline. In this trial, antiretroviral treatment of the HIV-infected partner substantially decreased transmission rates, yielding a hazard ratio of 0.04 (95% confidence interval, 0.01 to 0.27).3 In a subgroup analysis of two observational studies from the Cochrane review that included persons with a CD4 cell count of 350 per mm3 or greater, HIV transmission occurred in 61 untreated couples compared with none of the treated couples.
Antiretroviral therapy reduces transmission among HIV-discordant couples, and this randomized controlled trial confirms that this benefit also occurs in couples in which the partner with HIV infection has a CD4 cell count of 350 to 550 per mm3.