The Identification of a Novel HIV-1 CRF01_AE/B Recombinant Based on Near Full-Length Genomic Analysis in Yunnan Province, China.

Recombination contributes substantially to the genetic diversity of HIV-1. Recently, many kinds of circulating recombinant forms (CRFs) and unique recombinant forms (URFs) were identified in China, especially in areas with multiple subtypes of HIV-1 circulating. Yunnan, which borders the "Golden triangle" region of South China, is an epicenter of HIV-1 infections in China. Multiple subtypes, including subtypes B, CRF01_AE, CRF07_BC, and CRF08_BC, were found epidemic in the area. Many URFs composed of subtypes B and C genomes were identified in Yunnan; however, CRF01_AE/B recombinant form is relatively rare. In this study, we identified a novel recombinant form of CRF01_AE/B, which was isolated from a heterosexual transmitted individual. The genomic structure of the strain is distinctly different from any previously reported URFs. Three CRF01_AE segments were inserted into the subtype B backbone genome. In the past few years, many kinds of URFs and CRFs have emerged and spread quickly in China, which implies that coinfection or super infection of more than one HIV-1 subtype might be common in China, especially in Yunnan. Therefore, more work is needed to monitor the appearance of URFs and survey the epidemiologic significance of the new recombination.