Heterosexual HIV Transmission Study (HATS)

PRIMARY: To identify sexual behaviors and biological factors associated with an increased risk of heterosexual HIV transmission. SECONDARY: To assess the effect of safer sex counseling on behavior of sexually active heterosexuals in which one member of the couple is infected with HIV. To create a repository of serum, peripheral blood mononuclear cells, semen, and cervico-vaginal washings from heterosexual couples who are concordant (both partners HIV infected) and discordant (one partner HIV infected) with respect to HIV infection. In the United States, the number of AIDS cases attributed to heterosexual transmission, although still a small percentage of the total number of reported cases, is the most rapidly growing category. The rate at which HIV is transmitted between heterosexual couples and the factors that may impede or enhance heterosexual transmission are important to understanding and slowing the worldwide HIV epidemic.