OBJECTIVETo study the epidemic status of human immunodeficiency virus type 1 (HIV-1) subtypes in Shenzhen and to study their transmission source and routes.

METHODSHIV-1 env and gag genes were amplified by nested PCR from uncultured peripheral blood mononuclear cells (PBMCs) obtained from 122 HIV-1 carriers confirmed in Shenzhen. The C2-V3 region (about 450 bp) of HIV-1 env and P17/ P24 region were sequenced.

RESULTSAmong 122 samples, 6 HIV-1 strains including 3 circulating recombinant forms (CRFs) of CRF01_AE, CRF08_BC, CRF07_BC and 3 subtypes of B', B, C were found in Shenzhen, and the percentages were 45.1% (55/122) for CRF01_AE, 31.1% (38/122) for CRF08_BC, 6.6% (8/122) for CRF07_BC, 14.8% (18/122) for B' subtype, 1.6% (2/122) for B subtype, and 0.8% (1/122) for C subtype. The intragroup genetic distances were (4.455 +/- 1.478)%, (2.997 +/- 1.345)%, (4.380 +/- 2.024)%, (5.186 +/- 2.487)%, and (4.869 +/- 2.638)%, respectively. In comparison with the sequence of respective international strains 01AE. TH. 90. CM240, 97CNGX-9F, CN. 97. C54A, B. US. 83. JRFL, and RLA2, the genetic distances were (5. 228 +/- 0.823)%, (3.634 +/- 1.073)%, (4.233 +/- 1.119)%, (4.950 +/- 2.564)%, and (5.795 +/- 2.198)%, respectively. The major subtypes found in injection drug users (IDUs) were CRF07_BC, CRF08_BC, and CRF01_AE strains. CRF01_AE and B' strains were epidemic mainly in sexual workers.

CONCLUSIONThere are 3 HIV-1 subtypes (B', B, C) and 3 CRFs (CRF01_AE, CRF08_BC, CRF07_BC) epidemics in Shenzhen. The predominant subtypes varies among different transmission routes. While CRF01_AE is predominant among sexual workers, CRF08_BC and CRF01_AE are major subtypes among IDU population.