Heterosexual Transmission of HIV

Couple at ZEHRP

At present, RZHRG is conducting an observational study to document heterosexual transmission of HIV. The main objective of this protocol is to study the incidence and demographic, behavioral, clinical and laboratory predictors of the heterosexual transmission of HIV in discordant couples. Our findings provide information about the proportion of cohabitating heterosexual couples living in Lusaka, Zambia, and Kigali, Rwanda, who have discordant HIV results (one partner is HIV negative and one partner is HIV positive), as well as information about the rate of male-to-female and female-to-male transmission of HIV after HIV counseling and condom skills training. The research also investigates why transmission happens in some couples and not in others--and whether transmission is related to the number of unprotected contacts, the presence of other sexually transmitted diseases or other vaginal infections--and advancement of HIV disease in the HIV+ partner.

Our Work

As part of the study, a cohort of HIV-discordant couples has been established and is currently maintained for future HIV and sexually transmitted infection prevention studies.


• Approximately 25 million Africans are HIV+ and 225 million adults are HIV- and married, at risk of acquiring HIV within their marriages.

•The U.S. government spends $2.2 billion annually – 10 percent of the entire U.S. bilateral foreign aid budget -- to provide antiretroviral therapy to 3 million Africans.

•Treating one ART patient over the course of 10 years costs about $7000.

•The World Health Organization (WHO) estimates that five new people are infected by HIV for every two who receive antiretroviral therapy (ART).

Testing results from ZEHRP sites, January 2002 - June 2006. With 12, 714 couples tested, 18% were found to be discordant- meaning one couple was HIV positive and the other was HIV negative. 50% of all couples were found to both have negative results, and 32% were found to both have positive results.

Research at RZHRG