HCV Transmission among Young IDUs in NYC

描述(由申请人提供)：这项研究的目的是确定曼哈顿下东区一群年轻的、高风险的注射吸毒者(IDU)与特定注射做法相关的感染丙型肝炎病毒(HCV)的风险，以及先前存在的丙型肝炎病毒特异性免疫反应的可能保护作用。丙型肝炎是人类免疫缺陷病毒(HIV)感染者中上升最快的机会性感染，已经成为艾滋病毒/丙型肝炎混合感染者死亡的主要原因。由于丙型肝炎病毒在注射吸毒者中比艾滋病毒更普遍，也更容易传播，预防丙型肝炎病毒成为预防注射吸毒者中艾滋病毒和其他血液传播感染的敏感模式。尽管我们对丙型肝炎病毒及其传播的了解取得了进展，但丙型肝炎病毒继续在注射吸毒者中迅速传播，这些注射吸毒者现在是发达国家大多数新的丙型肝炎病毒感染的原因。需要更好地了解与共用注射器和其他注射设备有关的风险，以及在准备和注射毒品期间出现的许多其他血液接触机会，以指导制定更有效的预防干预措施。这项拟议的研究将每两周采访100名未感染丙型肝炎病毒的高危注射吸毒者，并收集有关他们注射做法的详细信息，以检查与特定注射做法相关的风险。具体目的是：(1)确定与增加丙型肝炎病毒感染风险相关的具体注射做法，并估计每一种做法(A)风险的大小，(B)剂量-反应关系，以及(C)每一行为的传播率；(2)检查与研究采访者的长时间频繁互动如何影响采访者与计算机管理问题的相对表现；(3)检查某些背景因素对注射方法和丙型肝炎病毒传播的影响；以及(4)4.检查在基线水平的受试者中观察到的丙型肝炎病毒特异性细胞免疫反应是否起到保护作用，并估计任何这种作用的强度。这项研究的发现将有助于指导基于证据的丙型肝炎病毒预防干预措施的发展，允许更准确地模拟丙型肝炎病毒流行，并增强我们对丙型肝炎病毒特异性免疫的理解。

DESCRIPTION (provided by applicant): The purpose of this study is to determine the risks of acquiring hepatitis C virus (HCV) infection associated with specific injection practices in a cohort of young, high-risk injection drug users (IDUs) on the Lower East Side of Manhattan, and the possible protective effect of pre-existing HCV-specific immune responses. Hepatitis C is the most rapidly rising opportunistic infection in persons with human immunodeficiency virus (HIV) infection and already the leading cause of death in persons with HIV/HCV co-infection. Because it is more prevalent and more readily transmitted among IDUs than HIV, HCV prevention serves as a sensitive model for the prevention of HIV and other bloodborne infections among IDUs. Despite advances in our understanding of HCV and its transmission, HCV continues to spread rapidly among IDUs, who now account for most new HCV infections in the developed world. A better understanding of the risks associated with the sharing of syringes and other injection equipment and many other opportunities for blood contact that arise during the preparation and injection of drugs is needed to guide the development of more effective prevention interventions. The proposed study will interview 100 high-risk, HCV-uninfected IDUs every two weeks and collect detailed information about their injection practices in order to examine the risks associated with specific injection practices. The specific aims are to: (1) Determine the specific injection practices associated with an increased risk of HCV infection, and estimate for each (a) the magnitude of the risk, (b) the dose-response relationship, and (c) the per-act transmission rate; (2) Examine how a prolonged period of frequent interaction with a research interviewer affects the relative performance of interviewer- vs. computer- administered questions; (3) Examine the impact of certain contextual factors characterizing injection settings on injection practices and HCV transmission; and (4) 4. Examine whether HCV-specific cellular immune responses observed in subjects at baseline exert a protective effect, and estimate the strength of any such effect. The findings from this study will help guide the development of evidence-based HCV prevention interventions, permit more accurate modeling of the HCV epidemic, and enhance our understanding of HCV- specific immunity.