Characterization of an imported HIV-1 A1/A7/G recombinant in China.

Background: International migration has accelerated the HIV-1 spread across national borders, gradually reducing the restrictions on the geographical distribution of HIV-1 subtypes. Subtypes A and G are globally recognized as the third and sixth most dominant HIV-1 genotypes, mainly prevalent in Africa, but rarely detected in China. Here we reported an imported HIV-1 recombinant which was composed of sub-subtypes A1 and A7 of subtype A and subtype G genes in a Chinese female. This virus was the first HIV-1 recombinant including A7 genes reported in the world.

Case Presentation: The near full-length genome (NFLG) was obtained from the plasma sample of the female in an HIV-1 molecular epidemiological survey with 853 participants in China. Phylogenetic analyses showed that this NFLG sequence contains three A7 segments, four G segments and one A1 segment with seven breakpoints, and all these segments were closely related to HIV-1 references circulating in Africa. The evidence from epidemiological investigation indicated that this female participant had a more-than-two-years heterosexual contact history with a fixed partner from Nigeria, a country in west Africa, which further supported the results of phylogenetic analyses. By the Bayesian phylogenetic analyses, the times of most recent common ancestors (tMRCA) of the partial pol gene (nt2308-3284, A7 region) and full-length vpr-vpu plus partial env gene (nt5534-6858, G region) were estimated around 1989 and 1984, respectively.

Conclusions: In this study, by using the NFLG sequencing, we identified an imported HIV-1 A1/A7/G recombinant which was estimated to originate around 1980s in Africa and introduced into China with international migration. This study highlighted the complexity of the global HIV-1 epidemic, the necessity of using genome sequences to determine HIV-1 genotypes and the importance of real-time monitoring of HIV-1 infection among international migrants and travelers.