The identification of a novel HIV-1 CRF01_AE/B recombinant using the near full length genome in Jiangsu Province, China

HIV-1 genotype diversity and distribution characteristics among heterosexually transmitted population in Jiangsu province, China

Background

Heterosexual transmission has contributed greatly to the current HIV-1 epidemic in China. However, the HIV-1 genetic characteristics in the heterosexually transmitted population in Jiangsu province remained unclear.

Methods

A molecular epidemiological investigation on heterosexual transmission of HIV-1 was conducted across Jiangsu province. 301 HIV-1 patients infected through heterosexual transmission were involved in this study. The epidemiological information was investigated by trained staff via face-to-face interviews. Blood samples were taken from each patient, HIV-1 RNA was extracted from the plasma, and used for amplifying the gag and env genes followed by further products sequencing. The genotypes of HIV-1 were determined using phylogenetic tree analyses in the neighbor-joining method.

Results

A total of 262 samples were successfully taken for genotyping. The main subtypes which accounted for 90.5% of all HIV-1 strains are CRF01_AE (45.4%), CRF07_BC (21.4%), subtype B (12.6%), CRF08_BC (11.1%). Minor subtypes were also detected, such as CRF68_01B, subtype C, CRF55_01B, CRF02_AG and subtype A. Time trend analysis suggested the prevalence of subtype B and CRF08_BC decreased gradually, but the prevalence of CRF01_AE increased over time. A relatively higher prevalence of CRF07_BC in Central Jiangsu and subtype B were detected in South Jiangsu, while a relatively lower prevalence of subtype B and CRF08_BC were detected in Central Jiangsu.

Conclusion

Complex and unbalanced HIV distribution characteristics suggest that heterosexual transmission of HIV needs to be taken seriously. It is necessary to implement more effective and comprehensive intervention strategies for further control of HIV-1 dissemination.

Near Full-Length Genomic Characterization of HIV-1 CRF01_AE/B Recombinant Strains Identified in Hebei, China

This study reports a novel HIV-1 recombinant form of CRF01_AE/B that was isolated from a 22-year-old male individual (HE150308) residing in Hebei province, China. The near full-length genome (NFLG) phylogenetic tree showed that the strain was clustered with CRF01_AE reference sequences and placed at the peripheral position within the branch of CRF01_AE strains. The bootscaning and similarity plot analysis revealed that the NFLG of this novel recombinant was composed of eight interlaced segments, including four CRF01_AE and four subtype B segments separated by seven breakpoints observed in the gag, pol, and nef regions of HIV-1 genome. Phylogenetic analysis demonstrated that the CRF01_AE subregions were from the previously identified CRF01_AE cluster 5, and the B subregions were correlated with the B strains originated from Europe and America. They were all the lineages widely prevalent in men who have sex with men (MSM) population in China. In recent years, a large number of recombinants between CRF01_AE and B strains are constantly emerging in the MSM population in China. This continual and recurrent recombination between CRF01_AE and B in high-risk group people deserves more attention and further monitoring.

Geographic Distribution and Temporal Trends of HIV-1 Subtypes through Heterosexual Transmission in China: A Systematic Review and Meta-Analysis

Background: Heterosexual transmission (HST) has become the current predominant transmission pathways of the HIV-1 epidemic in China. The aim of this study was to explore the geographic and dynamic change of HIV-1 subtypes through HST in China from published studies. Methods: Several electronic databases were searched to identify the studies, and the overall prevalence of HIV-1 subtypes was estimated by a meta-analysis method. Subgroup analysis was conducted by study region and time period. Publication bias was evaluated using Egger's test. The χ² test was used to evaluate the proportion differences among subgroups. Sensitivity analysis was carried out to assess the stability of the overall prevalence estimates. Results: 42 studies were included in our final analysis. The overall prevalence of CRF01_AE was 46.34% (95% CI: 40.56-52.17%), CRF07_BC was 19.16% (95% CI: 15.02-23.66%), B/B' was 13.25% (95% CI: 9.68-17.25%), CRF08_BC was 10.61% (95% CI: 7.08-14.70%), and C was 4.29% (95% CI: 1.85-7.48%). In subgroup analysis, the prevalence of CRF01_AE and CRF07_BC increased, while the prevalence of B/B' decreased over time, whereby the prevalence of CRF07_BC and CRF08_BC have exceeded that of B/B' since 2010. A significant higher prevalence of CRF01_AE was found in the South provinces, CRF07_BC in East provinces, CRF08_BC and C in Southwest provinces, and B/B' in North provinces. Conclusions: The HIV-1 prevalent strains have evolved into complicated and diverse subtypes, and the proportion of HIV-1 subtypes through HST has changed constantly in different regions and periods in China. This highlights the urgent need to vigorously strengthen the prevention and control of the HIV-1 epidemic.