OBJECTIVETo study the epidemic status of human immunodeficiency virus type 1 (HIV-1) subtypes and sequence variations in Henan province and to explore their epidemic characteristics and transmission sources and routes.

METHODSHIV-1 env gene was amplified by nested PRC from uncultured peripheral blood mononuclear cells (PBMCs) obtained from 1157 HIV-1 carriers confirmed in Henan from 2005 to 2006. The C2-V3 region (about 350450 bp) of HIV-1 env was sequenced.

RESULTSOf 1157 samples, there were 4 HIV-1 strains including subtype B', C and recombinant subtype BC and AE, accounting for 96.456% (1116/1157), 0.346% (4/1157), 2.593% (30/1157) and 0.605% (7/1157), respectively. In comparison with the sequences of the international strains of RL42, C.95in21068, 07BC.CN.97.C54A and 01AE.TH.90.CM240, the genetic divergence was (8.971 +/- 3.182)%, (5.109 +/- 0.112)%, (3.568 +/- 0.254)% and (4.775 +/- 0.128)%, respectively. The phylogenetic tree analysis showed that 1116 Henan B' strain was closely related to those of Thailand B' and was far different from other international subtypes. The major transmit route in subtype B' strain was mainly found among former blood donators, while sexual transmission was the major route for BC spreading. For AE, the major transmission was sex and blood transfusion, and sex was defined as the major route for C.

CONCLUSIONThere are four HIV-1 strains including subtype B', C and recombinant subtype BC and AE identified in Henan province currently, and the dominant subtype B' is closely related to HIV-1 strains of Thailand B'. While, for non-B' subtype, there exists the aggregating phenomenon in some local areas. Therefore, it is necessary to attach importance and to strengthen the HIV test and surveillance on migrant populations.