HIV-1 Thai B strain has spread out of former plasma donors into general population through sexual contact in Henan, China.

Henan, China is characterized by the outbreak of HIV epidemic of Thai B strain in former plasma donors in 1990s. After the forbidden of paid blood donation, whether Thai B strain will spread out of former plasma donors into sexual transmitted population is unknown. To answer the question, phylogenetic analysis was used to explore relationships of HIV strains circulating in those two populations in the study. HIV-1 sero-positive drug-naïve patients infected through sexual contact were enrolled into the study. Full length gag and pol genes were amplified with nested RT-PCR followed by sequencing and phylogenetic analysis. The genotypes of anti-HIV drug resistance were also analyzed with available pol genes. HIV subtypes were determined in 249 individuals from 288 participants. Subtype B was dominant (202/249, 81.1%), followed by CRF01_AE (25/249, 10.0%), CRF07_BC (14/249, 5.6%), C (4/249, 1.6%), URF (3/249, 1.2%), and CRF08_BC (1/249, 0.4%). Most of subtype B strains belong to Thailand B lineage. All of Thai B strains identified in sexual transmitted population intermixed with those from former blood donors in phylogenetic tree, suggesting close phylogenetic relationship between strains epidemic in those two populations. TDR was identified in 9.9% individuals. Thai B strain has spread out of former blood donors in Henan province. The finding will contribute to understanding the distribution and evolution of HIV-1 in Henan province and also provide clue to behavior change intervention.