Effect of Antiretroviral Therapy on Risk of Sexual Transmission of HIV Infection and Superinfection

The past decade has seen substantial advances in the development of antiretroviral therapy (ART)—medications used in combination to reduce the replication of HIV virus and treat HIV-infected persons. Because of these medications, many HIV-infected persons are able to reduce levels of virus in the bloodstream (plasma viral load) to undetectable levels. Data suggest that HIV-infected persons with undetectable viral load are less infectious, and may be less likely to transmit HIV via sexual contact. This fact sheet summarizes the implications of these data to individual couples and to the potential impact of ART in the prevention of HIV transmission within populations.