Identification of a Novel HIV-1 Recombinant Form (B/C) in Men Who Have Sex with Men in Shaanxi, China

Identification of a Novel HIV-1 Unique CRF01_AE/C Recombinant in Yan'an City, Shaanxi Province

A wide variety of HIV-1 recombinants are constantly discovered in China. Comprehensively monitoring the genetic diversity of HIV-1 is very essential for understanding the molecular epidemiology and controlling the spread of the HIV-1 epidemic. In this study, we presented a novel HIV-1 unique CRF01_AE/C recombinant (19YA001) isolated from a female patient infected HIV-1 through heterosexual transmission in Yan'an city, Shaanxi province. The near full-length genome analyses showed 19YA001 was divided into two CRF01_AE and one C segments by two breakpoints observed in the vif/vpr region. To date, this is the first report revealing the characteristic of HIV-1 subtype in Yan'an city. And this unique recombinant strain might imply that the genetic diversity of HIV-1 in Yan'an city is complex. However, the sample size is too small. Further larger studies of HIV-1 molecular epidemiology are urgently needed to provide a better understanding of HIV-1 diversity and transmission in this region.

Brief Report: Onward Transmission of Multiple HIV-1 Unique Recombinant Forms Among Men Who Have Sex With Men in Beijing, China

BACKGROUND

Unique recombinant forms (URFs) were generated in dually infected or multiply infected individuals, and some of URFs can be transmitted to many people resulting in the emergence of circulating recombinant forms (CRFs). We examined whether there was evidence for onward transmission of multiple URFs among men who have sex with men (MSM) in Beijing.

METHODS

A total of 146 MSM subjects with acute/early HIV-1 infection were recruited from the Beijing PRIMO clinical cohort between September 2010 and July 2012. HIV-1 full-length gag and partial pol, env genes were amplified and sequenced separately. Phylogenetic analysis and recombination analysis were performed to determine the viral genotypes. Single genome amplification and direct sequencing were used to confirm onward transmission of URFs.

RESULTS

CRF01_AE was the most common genotype (51.9%), followed by CRF07_BC (23.0%), subtype B (14.8%), URFs (7.4%), CRF65_cpx (2.2%), and CRF55_01B (0.7%). Multiple forms of URFs were identified, including CRF01_AE/BC, CRF01_AE/B, and CRF01_AE/C. Nine of the 10 individuals harboring URFs were infected by onward transmission of URFs. The remaining one individual was coinfected with CRF01_AE and CRF07_BC variants.

CONCLUSIONS

We introduced a new method to provide evidence for onward transmission of URF strains by examining the absence of intersubtype coinfection among early infected individuals. Onward transmission of multiple URFs was found among MSM in Beijing, China. Our findings call for a program of continuous molecular surveillance and have implications to prevention programs among MSM in China.

Characterization of a Novel HIV-1 CRF01_AE/CRF07_BC Recombinant Virus Form in Guizhou, China

We identified a novel CRF01_AE and 07_BC HIV-1 recombinant form in Guizhou province in southwest China. The phylogenetic analysis of the near full-length sequence reveals that it was divided into five segments by four breakpoints, and the CRF01_AE regions of the recombinant were clustered with subcluster 4 lineage of CRF01_AE, which mainly circulated among men who have sex with men (MSM) in China. The CRF07_BC regions of the recombinant were clustered with CRF07_BC lineage, which circulated among Chinese MSM. This is the first detection of a novel HIV-1 second-generation recombinant form (CRF07_BC/CRF01_AE) in Guizhou, which shows the increasing significance of heterosexual transmission contributing to the complexity of the HIV-1 epidemic in southwest China, and more effort measures should be taken to monitor the genetic evolution of HIV-1 strains and prevent HIV-1 transmissions.