Summary:HIV infection in Africa is primarily acquired through heterosexual activity, accounting for up to 80% of cases. Prostitutes and sexually promiscuous individuals are at particularly high risk of acquiring infection via this route. In the general population, women between the ages of 18 and 30 years are at increased risk of transmission. The role of cofactors, particularly concurrent sexually transmitted diseases (STDs), appears to facilitate heterosexual spread. These groups represent opportunities for targeted prevention programs aimed at education, increased condom use, prompt treatment of STDs, and reduction in the number of sexual partners. HIV infection acquired via blood transfusion may account for up to 10% of new cases of HIV infection. Children with malaria and nutritionally induced anemias are at special risk of acquiring infection by this route. Early treatment of malaria, surveillance for and treatment of malnutrition, adoption of rigorous criteria for blood transfusion, and implementation of machine-independent, low cost HIV screening programs in transfusion centers will help prevent these infections. As the epidemiology of HIV infection becomes better understood, other opportunities for technologically appropriate, cost-effective interventions will become available and will facilitate African HIV control and prevention programs.