Subtype G and multiple forms of A/G intersubtype recombinant human immunodeficiency virus type 1 in Nigeria

Multiple human immunodeficiency virus type 1 (HIV-1) genetic subtypes, inte rsubtype recombinants, and group O have been found in west central Africa. In Nigeria, where HIV-1 prevalence is rising rapidly, characterization of H IV-1 strains has been limited. Each of three full-length genome sequences a cquired to date shows evidence of recombination: two are largely subtype G with subtype A segments in the midgenome accessory region; the third, lbNG, is subtype G with the long terminal repeats and two segments of pol from s ubtype A. In this study, peripheral blood mononuclear cells obtained in 199 4-1995 from 10 patients hospitalized in northeastern Nigeria were evaluated by sequencing of the complete envelope and, from 7 patients, a portion of gag. Four patients harbored subtype G viruses and six patients had recombin ant viruses. Two had strains sharing the A/G recombinant structure of lbNG. Two had a previously undescribed recombinant, mostly subtype A, whose carb oxyl-terminal gp41 could not be classified. An A/G recombinant different fr om lbNG but similar to CA1, a Cameroonian strain, was found in one patient. The remaining patient had a strain that was otherwise subtype G but shared an unclassified carboxyl-terminal gp41 segment with the CA1-like strains. Other subtypes and group O were not found. (C) 1999 Academic Press.