Presence of diverse human immunodeficiency virus type 1 viral variants in Cameroon

Phylogenetic analysis of the gp41 region of 123 HIV-1-seropositive specimen s from Cameroon showed that 89 were subtype A (71% of these sequences were IbNg-like), 12 (10%) were subtype D, 11 (9%) were subtype G, 5 (4%; closely related to subtype F2) were subtype F, 1 was subtype H, 2 (1.6%) remained unclassifiable, while 3 were group O. Further analysis of the two unclassif iable specimens in gag(p24), pol(prot), and env (C2V3 or gp41) showed that one (98CM19) was a complex mosaic between subtype A in p24 and subtype J pr ot, and unclassifiable in env (C2V3 or gp41). The second, 98CM63, clustered distinctly from all known subtypes in p24, prot, C2V3, or gp41. 98CM63 clu stered with a specimen from Cyprus and these two geographically and epidemi ologically unlinked specimens, with their distinct clustering pattern, may represent a new subcluster of subtype A. In conclusion, these findings conf irm the high HIV-1 genetic variability and further suggest the continuous a ppearance of new viral strains in this population.