STUDY ON MOLECULAR EPIDEMIOLOGY OF HIV AND HEPATITIS VIRUS INFECTIONS IN ASIA

（A）亚洲艾滋病病毒的分子流行病学1）越南北方艾滋病病毒爆发：我们调查了最近越南-中国边境附近注射毒品使用者中艾滋病病毒爆发的性质。HIV-1 E亚型是分布在全国各地的主要毒株，无论危险因素如何。我们发现越南北方注射吸毒者中的大多数HIV-1 E亚型与邻近的中国广西凭祥市的HIV-1 E亚型具有显著的聚集性，在V3环下游12个氨基酸处共享一个独特的缬氨酸取代。数据表明，越南北方注射吸毒者中的艾滋病毒爆发是由于最近引入了一种高度同源的E亚型变异体（EV）所致，这种变异体与邻近的中国南方流行的变异体来源相近。2）缅甸中部出现了各种形式的艾滋病毒1亚型间重组体：除了在我们的研究中先前检测到的两种HIV-1亚型B'和E之外，我们还首次在中缅地区确定了HIV-1亚型C。 ...更多信息 nmar。约1/4的标本gag（p17）和env（C2/V3）亚型表达不一致。重组断裂点分析显示存在新形式的HIV-1亚型间C/B'和C/B'/E重组体。数据表明，B '、C和E多种亚型在缅甸中部共同传播，导致新形式的亚型间重组体的进化。3）影响泰国人群对HIV-1易感性和疾病进展的遗传多态性：在泰国使用不一致夫妇的横断面研究显示，CCR 5 927 T突变是与艾滋病毒抗性相关的重要遗传易感性，泰国1例感染。这是在亚洲人群中进行的首批报告之一。B）亚洲肝炎病毒的分子流行病学1）东南亚HGV新基因型的鉴定：我们最近在东南亚国家鉴定了一种新的庚型肝炎病毒（HGV）基因型。为了更详细地描述病毒基因组，我们克隆了属于新基因型的两种不同HGV分离株的全长核苷酸序列。这些分离株分别从缅甸人（命名为HGV-MY 14）和越南人（命名为HGV-VT 48）受试者的血清中回收。两株HGV均由9228个核苷酸（nt）组成，并且具有跨越8529 nt和编码2843个氨基酸残基的单个开放阅读框架。2）通过PCR进行HBV和HGV基因分型：开发了基于使用型特异性引物的PCR的简单且精确的基因分型系统，以允许确定HBV的基因型A至F和HGV的基因型1至4。通过这种新的方法，在东南亚的HBV和HGV基因型的流行情况进行了调查。结果表明，缅甸和越南最常见的病毒基因型为HBV C型和HGV 4型。有趣的是，B型HBV在越南也很流行。该检测系统被认为是HBV感染的分子诊断和大规模调查的有用工具。少

(A)Molecular epidemiology of HIV in Asia1)HIV outbreaks in northern Vietnam : We have investigated the nature of recent HIV outbreaks among injecting drug users (IDUs) near Vietnam-China border. HIV-1 subtype E was a principal strain distributed throughout country, regardless of risk factor. We found that the majority of HIV-1 subtype E among IDUs in northern Vietnam showed the significant clustering with those found in nearby Pingxiang city of China's Guangxi Province, sharing a unique valine substitution at 12 amino acids downstream of the V3 loop. The data indicated that HIV outbreaks among IDUs in northern Vietnam was caused by the recent introduction of a highly homogeneous subtype E variant(EV) of close origin of that prevailing in nearby southern China.2)Emergence of various forms of HIV-1 intersubtype recombinants in Central Myanmar : In addition to two HIV-1 subtypes B' and E previously detected in our study, we have identified HIV-1 subtype C for the first time in Central Mya … More nmar. Moreover, approximately 1/4 of specimens showed the discordance in gag (p17) and env (C2/V3) subtypes. The recombination breakpoint analyses revealed the presence of new forms of HIV-1 intersubtype C/B' and C/B'/E recombinants. The data suggest that multiple subtypes of B', C and E are co-circulating in Central Myanmar, leading to the evolution of new forms of intersubtype recombinants.3)The genetic polymorphism influencing the susceptibility to HIV-1 and disease progression in Thai population : Cross-section study using discordant couples in Thailand revealed that CCR5 927T mutation is an important genetic predisposition related to resistance to HIV-1 infection in Thai population. This is one of the first reports done in Asian population. Theses results would provide the information crucial to future vaccine strategies for this particular areas in Asia.B)Molecular epidemiology of hepatitis viruses in Asia1)Identification of novel genotype of HGV in Southeast Asia : We recently identified a novel genotype of hepatitis G virus(HGV) in Southeast Asian countries. To characterize the viral genome in more detail, we cloned the full-length nucleotide sequence of the two different HGV isolates belonging to the novel genotype. These isolates were recovered from serum of Myanmarese (designated HGV-MY14) and Vietnamese (designated HGV-VT48) subjects, respectively. Both HGV isolates were composed of 9228 nucleotides (nt) and had a single open reading frame spanning 8529 nt and encoding 2843 amino acid residues.2)HBV and HGV genotyping by PCR : A simple and precise genotyping system based on PCR using the type-specific primers was developed in order to allow for the determination of genotypes A through F of HBV and genotypes 1 through 4 of HGV. By this new method, the prevalence of genotypes of HBV and HGV was investigated in Southeast Asia. The results revealed that the most common viral genotypes were type C of HBV and type 4 of HGV in Myanmar and Vietnam. Interestingly, type B of HBV was also prevalent in Vietnam. This assay system is considered to be useful tool for molecular diagnosis of HBV infection and large-scale surveys. Less