Human retroviral infections in The Gambia: prevalence and clinical features.

The prevalence of infection with human immunodeficiency virus type 1 (HIV 1) is lower in west Africa than in other parts of Africa. Human immunodeficiency virus type 2 (HIV 2) has been isolated from west African patients and may be transmitted by heterosexual contact. The prevalence of antibodies to HIV 1 and HIV 2 was studied by enzyme linked immunosorbent assay (ELISA) among various groups of subjects in The Gambia, west Africa--namely, prostitutes, blood donors, patients with suspected infection with HIV, patients attending clinics for sexually transmitted diseases, and patients with tuberculosis. Four cases of the acquired immune deficiency syndrome (AIDS) due to infection with HIV 1 were detected, of which three had been acquired abroad. No other subject was found to be positive for antibodies to HIV 1. The prevalence of antibodies to HIV 2 among the patients attending clinics for sexually transmitted diseases was found to have increased from 0/117 in 1984 to 10/185 (5%) in the last six months of 1986. One out of 278 blood donors was positive for antibodies to HIV 2 as were 10 out of 80 patients with suspected AIDS. HIV 2 seems to be transmitted sexually, and, although it has been present for only a short time, it seems to be endemic in The Gambia and is pathogenic.