Human immunodeficiency virus transmission among heterosexual couples in Central Africa.

From February to June 1986, 150 heterosexual couples with at least one HIV-seropositive member were recruited in the 'Centre Hospitalier de Kigali', Kigali, Rwanda. Of the 138 HIV-seropositive couples in whom both members were tested, 124 (90%) were sexual unions between two antibody-positive partners, illustrating the high efficiency of the heterosexual transmission of HIV. A comparison of these 124 couples with 150 HIV-seronegative couples showed that, in the husbands, seropositivity is significantly associated with sexual contacts with prostitutes and history of sexually transmitted disease (STD) within the past 2 years. Seropositive wives were less likely to be in their first marriage and reported more episodes of STD than seronegative ones. Seropositive couples were similar to seronegatives in their history of blood transfusion, male circumcision and overall use of contraception but not in their use of oral contraceptive pills, which was more frequent; they were more often in polygamous unions. Discriminant analysis showed that STD, sexual contacts with prostitutes and the number of previous unions are the most powerful independent variables associated with the seropositivity of the couples. Most of the risk factors for the couples were the risk factors for the husband, suggesting that in most cases the husband acquired the HIV infection and passed it to his wife.