Genetic Characterization of a Novel HIV-1 Second-Generation Recombinant Form (CRF01_AE/CRF07_BC) Identified in Yan'an City, China.

Owing to co-epidemic of CRF01_AE and CRF07_BC in China, increasing numbers of the second-generation recombinants between them have been identified especially among sexual population. In this study, we identified a unique CRF01_AE/CRF07_BC recombinants from a male HIV-1 positive individual (18YA004) infected by heterosexual contact in Yan'an city, Shaanxi province. The near full-length genome analyses showed 18YA004 was divided into six fragments by five breakpoints located in the , , , and gene, respectively. Three CRF01_AE segments (segments I, III, and V) were all clustered within the cluster 4a lineage, exclusively circulating among MSM in the northern China. Coupled with our previous finding of CRF01_AE/C recombinant in Yan'an city, the emergence of CRF01_AE/CRF07_BC strain further suggested coexistence of multiple HIV-1 genotypes here. Therefore, it is necessary to continue monitoring the molecular epidemiology of HIV-1 among high-risk groups to obtain a better understanding of the genetic complexity and transmission of HIV-1 in this region.