Genome mosaic structure of two novel HIV-1 recombinant forms (CRF01_AE/B) in men who have sex with men in Hebei, China

Background Homosexual contact is the main route of human immunodeficiency virus type one (HIV-1) transmission in Cangzhou Prefecture, Hebei, China. Moreover, the number of circulating recombinant forms (CRFs) and unique recombinant forms (URFs) in this key population is ever increasing. Methods In this study, we identified two novel URFs (hcz0017 and hcz0045) from two men who have sex with men (MSM) based in Cangzhou Prefecture. Phylogenetic and recombinant breakpoint analyses, based on the near full-length genomes (NFLGs) of the two novel URFs, showed that they originated from a recombination between HIV-1 CRF01_AE and subtype B. Results HXB2 numbering revealed that the NFLGs of hcz0017 and hcz0045 each contained the following seven subregions: hcz0017: I B (790–1,171 nt), II CRF01_AE (1,172–2,022 nt), III B (2,023–4,469 nt), IV CRF01_AE (4,470–5,866 nt), V B (5,867–7,462 nt), VI CRF01_AE (7,463–8,379 nt), VII B (8,380–9,411 nt); hcz0045: I CRF01_AE (790–5,147 nt), II B (5,148–5,614 nt), III CRF01_AE (5,615–6,035 nt), IV B (6,036–6,241 nt), V CRF01_AE (6,242–7,325nt), VI B (7,326–8,254 nt), VII CRF01_AE (8,255–9,411 nt). Moreover, the two MSM from whom the novel URFs originated from were diagnosed as recently HIV-1-infected, suggesting that the high prevalence of HIV-1 among MSM was related to high-risk sexual activity such as unprotected anal sex and multiple sexual partners. Conclusions Our results highlight the need to continually monitor HIV-1 diversity in Hebei and its neighboring provinces to achieve a more effective control of HIV-1 spread within the MSM community.