Identification of a novel HIV-1 circulating recombinant form (CRF62_BC) in western Yunnan of China.

We report here a novel HIV-1 circulating recombinant form (CRF62_BC) that was isolated from three epidemiologically unlinked individuals [one from an injecting drug user (IDU); two from heterosexuals] in Dehong prefecture of western Yunnan province. CRF62_BC harbored two subtype B segments in the pol and vpu-env regions in a subtype C backbone. Subregion tree analysis demonstrated that subtype B regions originated from a Thai-B (subtype B') lineage and the subtype C region was from an India C lineage. CRF62_BC is the fourth CRF composed of subtypes B' and C known to date after CRF07_BC, CRF08_BC, and CRF57_BC, which were originally found among IDUs in China. The emergence of CRF62_BC may indicate the continual generation of new recombinant strains in various high-risk populations in western Yunnan. This may complicate the development of effective vaccines to limit the HIV-1 epidemic and increase the difficulty of AIDS prevention and control in China.