HCV Transmission among Young IDUs in NYC

描述（由申请人提供）：本研究的目的是确定曼哈顿下东区一组年轻、高风险注射吸毒者（IDUs）中与特定注射实践相关的获得丙型肝炎病毒（HCV）感染的风险，以及预先存在的HCV特异性免疫应答的可能保护作用。丙型肝炎是人类免疫缺陷病毒（HIV）感染者中增长最快的机会性感染，并且已经是HIV/HCV合并感染者死亡的主要原因。由于HCV在注射吸毒者中比艾滋病毒更流行，更容易传播，因此预防HCV是预防注射吸毒者中艾滋病毒和其他血液传播感染的一种敏感模式。尽管我们对HCV及其传播的了解有所进展，但HCV继续在注射吸毒者中迅速传播，他们现在占发达国家大多数新的HCV感染。需要更好地了解与共用注射器和其他注射器具有关的风险以及在制备和注射药物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名高风险、未感染HCV的注射吸毒者，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。具体目标是：（1）确定与HCV感染风险增加相关的特定注射实践，并估计每种注射实践的（a）风险程度，（B）剂量-反应关系，和（c）每次行为传播率;（2）检查与研究访问者长时间频繁互动如何影响访问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实践和HCV传播的影响;以及（4）4.检查基线时在受试者中观察到的HCV特异性细胞免疫应答是否发挥保护作用，并估计任何此类作用的强度。这项研究的结果将有助于指导循证HCV预防干预措施的发展，允许更准确地模拟HCV流行，并提高我们对HCV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.