Research On Molecular Epidemiology Of HIV-1among Long Distance Truck Drivers At Ports In Yunnan Province

Acquired Immune Deficiency Syndrome (AIDS) is a serious infectious disease caused by human immunodeficiency virus (HIV) infection. HIV infection and subsequent replication destroyed cellular immune function, which lead to a variety of human conditional pathogens infection, eventually to death. Before the end of2011, the survived HIV-infected people and patient worldwide had been reached34million (31.4million-35.9million). In China, the HIV infected individuals and AIDS patients had been reached78million(62-94million) with the national rate of0.058%(0.046%-0.070%). Yunnan Province is neighbored with the world’s largest drug producer-the "Golden Triangle" region. Because of the special location, HIV was is introduced into Yunnan firstly, and then to other provinces of China through different transmission routes. In the1990s, Yunnan was presented with the co-circulating of multiple genotypes and recombinants including B’, C, CRF01-AE, etc. After nearly20years of co-evolution, numerous unique recombinants had developed in Yunnan. With the frequent personnel exchanges and trade between China and Southeast Asia countries, immigration staff and frequent cross-border foreign resident workers through ports of Yunnan was increasing. In view of the special geographical location of Yunnan Province in China, it is necessary to have the research on the actual HIV molecular epidemiological characteristics of Yunnan Province. It may contribute to our understanding on HIV epidemic situation and predicting the prevalence trend, as well on HIV infection prevention and the development of vaccine.In this study, a total of204long distance truck drivers were recruited at ports of Yunnan Province. Most of them came from Ruili prot (186/204,91.18%) and the rest from the other ports, Lincang, Puer, etc. All of them are all male,14are Chinese and the rest are Burmese. The most of drivers (197/204,96.57%) are young person with the age of20to40years old. Because of privacy consideration, most people haven’t informed their infection route. However, the sex transmission route is highly suspected. Using the reverse transcription and nested-PCR method, geg-pol gene fragments were successfully amplified. In detail, the gag-pol fragment (2.6kb) was divided into three sections including gag, gag-prot and pro-RT, they have the length of1155bp,885bp and1010bp, were amplified separately. The obtained fragments were submitted to sequencing. After the raw sequence diagram reviewing and sequence editing, phylogenetic trees was reconstructed together with derived reference sequence. Phylogenetic analysis showed that the previous genotyping methods have some limitations, parts of recombinant couldn’t be accurately determined. Here, we got the three overlapping segments splicing into gag-pol gene sequences of about2.6kb. Based on this long length sequence, phylogenetic analysis was performed. It was shown the genotyping results have the high consistence with that based on full-length sequence. This makes the genotyping more simple and believable. Among the genotype determined204samples, CRF01_AE was discovered as the predominant genotype (123/204,60.29%), followed with subtype C (35/204,17.16%), subtype B (22/204,10.78%). In addition,13cases (6.38%) were classified as CRF08-BC and CRF07-BC. Of note,4cases were determined as URFs-BC, the second generation recombinant of CRF08-BC and CRF07-BC, and7cases (3.43%) were CRF01-AE/C/B’constituted CRF-01B reorganization. Using Beast software, the origin time of major circulating CRF01-AE, C and B were analyzed. It was deduced that origins time is1983,1960,1975respectively.Due to its high variability, the occurring of many new HIV-1subtypes and recombinant is still in process.11identified cases of unique recombinant in this study were analyzed to clarify the position of breakpoints using Simplot software. It was shown that the mosaic structure of unique recombinants is similar to the structure of CRF08-BC and CRF07-BC, which taken subtype C as a skeleton, inserted1-4subtype B’gene fragment into the skeleton. The four cases of recombinant have different breakpoint locations, breakpoints of sample No.06022are at1205-1236nt,1590-1647nt,2444-2480nt (nucleotide numbering relative to HXB2) respectively. Four relative breakpoint regions were identified in sample06122at positions1183-1243nt,1697-2025nt,2344-2490nt,2721-2806nt. Sample10028also presented four relative breakpoints at1190-1250nt,2008-2208nt,2435-281lnt,2883-3048nt. Sample cl2122is special, just have one recombinant breakpoint location at2329-3063nt. The structure of10024,10115,11103consisted of CRFOl-AE and B subtype is similar to the structure of CRF52-01B, CRF55-01B, CRF59-01B. They make subtype CRFOl-AE as a skeleton, inserted B’subtype gene fragment at2532-3290nt,2609-3290nt,2509-3290nt respectively. The structure of08102,11064,11085,11103consisted of CRFOl-AE and C subtype is different from the structure of others. The structure of08102and11103are similar which inserting subtype C gene fragment at2548-3021nt and2555-3019nt respectively. The structure of11064is similar to that of11085, inserting subtype C gene fragment at1725-2449nt and1730-2363nt respectively.In summary, a simple and effective assay for genetic subtyping had been established. Using this method, the characters of HIV-1molecular epidemiology among long distance truck drivers at ports of Yunnan Province have been elucidated. The findings will definitely provide an important data for HIV-1prevention and vaccine development.