Predominance of human immunodeficiency virus type 2 subtype B in Abidjan, Ivory Coast

We analyzed the genetic variability and phylogenetic relationships among 28 HIV-2 strains collected from patients enrolled in an HIV epidemiologic stu dy in Abidjan, Ivory Coast, during 1995-1996, Although both subtype A (n = 8; 29%) and subtype B (n = 20; 71%) were present in this sampling, the majo rity of infections were caused by subtype B viruses. These findings contras ted with the reported predominance of HIV-2 subtype A in other African coun tries. The broad genetic diversity identified among protease gene sequences for HIV-2 subtype A (6%; range 3-15%) and subtype B (7%; range, 2-12%), an d their presence in Abidjan during the 1980s, document a long coexistence o f two viral subtypes in Ivory Coast. Our data indicate that viruses of subt ypes A and B have contributed to the HIV-2 epidemic in Ivory Coast.