乙型肝炎病毒（HBV）、丙型肝炎病毒（HCV）和人类免疫缺陷病毒（HIV）是经血传播的严重危害人类健康的病原体。本课题组发现重庆某地的HBV B型和C型病毒在近年来群体扩张超过10倍，或许是重庆地区HBV爆发的预警。因此，本研究将采集重庆14个区市县HBV/HCV/HIV感染者的血液样本，对有信息位点的病毒基因片段进行测序，通过测序结果分析HBV/HCV/HIV的遗传多样性并评估这三种病毒的核酸检测试剂在重庆地区能否完全有效；通过生物信息学方法计算这三种病毒在重庆的系统发育位置，亲缘地理关系和群体遗传动力；通过人口统计学信息与病毒基因型/亚型/重组型的结合分析，研究三种病毒的分子流行病学；应用分子钟检测，推断三种病毒在重庆各地的起源分化和可能的扩张爆发时间。本课题所得结论能有方向性的指导重庆地区HBV/HCV/HIV的检测方案，同时，还能为重庆地区这三种病毒的认知和防控提供地域性的指导。

Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), and Human Immunodeficiency Virus (HIV) are the most hazadous blood-borne pathogens which extremely harm to public health. Recently, based on our research, genotype B and genotype C of HBV have found a 10 fold expansion in Chongqing Dianjiang county during last 5 years. This phenomenon might be a precaution of an edemic hepatitis B virus break out. Therefore, in this research, genome fragments obtained from patients which contain informative sites will be amplified and sequenced from 14 area in Chongqing. The full validity of realtime PCR conmertial assay will be evaluated based on the genetic diversity analysis for each sequence of HBV, HCV and HIV to ensure whether the kit could cover all geneypes, subtypes and recombinant forms of those virus. Using bioinformatics tools, the phylogeny, phylogeography and population dynamics of HBV, HCV and HIV distributed in Chongqing will be determined. Based on phylogenetic analysis, the molecular epidemiology of HBV, HCV and HIV in Chongqing will be performed with the demographics information of patients. The conceivable origin and expantion time, as well as the genetic structure and historical demographics of each virus population will be investigated by molecular clock inference under certain evolutionary models and universal rates. We anticipate that, according to this investigation, the results of this study may provide a guidience to the detection plan for HBV, HCV and HIV circulated in Chongqing. At the same time, the results will also shed lights on prevention , control and vigilance of HBV, HCV and HIV in Chongqing.