HIV Risk and Neighborhood Networks of New IDUs

描述（由申请人提供）：新的注射吸毒者（IDUs）在开始注射后的最初几年内有感染丙型肝炎病毒（HCV），乙型肝炎病毒（HBV）和艾滋病毒的风险。然而，新注射者的感染风险因种族/民族而异，非洲裔美国人比白人新注射者感染风险更高。风险行为本身并不能充分解释为什么非裔美国注射吸毒者有更大的感染风险。新注射者感染风险的种族/民族差异可能与接触感染风险的不同概率有关，这可能源于以社会为中心（直接和间接连接的注射吸毒者群体）和以自我为中心（直接连接的注射吸毒者群体）传播网络的差异。新注射吸毒者传播网络的种族/族裔差异也可能受到社区在提供减少危害和其他保健服务方面的差异以及社区社会和自然环境的其他差异的影响，因为注射吸毒者往往按种族/族裔在地理上分隔在不同的社区。在本研究中，我们将调查纽约市两个高危社区中HIV、HCV和HBV感染的社会中心和自我中心网络风险，其中一个社区以非洲裔美国人为主，另一个社区以新注射吸毒者为主。采用嵌入前瞻性队列的连续横断面设计，我们将比较以非洲裔美国人为主的新注射人群和以白人为主的新注射人群，以确定以下方面的差异：(1)HIV、HCV和HBV的患病率和发病率；(2)社会中心和自我中心网络与HIV、HCV和HBV传播的关系；(3)以社会为中心和以自我为中心的网络与风险和降低风险行为、感染风险和预防知识、减少伤害和其他卫生服务的获取和利用之间的关系；(4)社会中心和自我中心网络、风险和降低风险的行为和做法维持或改变的相关因素，以及这些因素与HIV、HCV和HBV血清转换率的关系；(5)利用民族志方法和地理信息系统，探讨社区因素与网络和行为感染风险的关系。了解社区环境、网络特征和行为在多大程度上影响新注射者感染或传播艾滋病毒、丙型肝炎病毒和乙型肝炎病毒的风险，有助于制定针对高危社区新注射者及其注射伴和性伴侣的结构性干预措施。

DESCRIPTION (provided by applicant): New injecting drug users (IDUs) are at risk of becoming infected with the hepatitis C virus (HCV), the hepatitis B virus (HBV) and HIV within the first few years after they start to inject. However, the risk of infection among new injectors varies by race/ethnicity, with African Americans at greater risk of infection than white new IDUs. Risk behaviors alone do not sufficiently explain why African American IDUs are at greater risk of infection. Racial/ethnic differences in the risk of infection among new injectors may be related to different probabilities in the risk of exposure to infection, which may stem from differences in sociocentric (groups of directly and indirectly connected IDUs) and egocentric (groups of directly connected IDUs) transmission networks. Variation by race/ethnicity in the transmission networks of new IDUs may also be influenced by neighborhood differences in the provision of harm reduction and other health services, as well as other differences in the social and physical environment of neighborhoods, since IDUs are often geographically separated by race/ethnicity into different neighborhoods. In this study, we will investigate the sociocentric and egocentric network risks for infection with HIV, HCV and HBV in two high-risk neighborhoods in New York City, one of which is predominantly African-American and the other in which new IDUs are predominantly white. Using a sequential cross-section design with an imbedded prospective cohort, we will compare a predominantly African-American group of new injectors and a predominantly white group of new injectors m geographically separate neighborhoods to determine differences in: (1) The prevalence and incidence of HIV, HCV and HBV; (2) The relationship of sociocentric and egocentric networks to HIV, HCV, and HBV transmission; (3) The relationship of sociocentric and egocentric networks to risk and risk reduction behaviors, knowledge of infection risk and prevention, and access to and utilization of harm reduction and other health services; (4) Factors associated with the maintenance or change in sociocentric and egocentric networks and risk and risk reduction behaviors and practices, and the relationship of these factors to the rate of HIV, HCV, and HBV seroconversions; and (5) using ethnographic methods and Geographic Information Systems, to explore the relationship of neighborhood factors to network and behavioral infection risk. Understanding the extent to which the multi-level influences of neighborhood context, network characteristics and behavior shape the risk of acquiring or transmitting HIV, HCV and HBV among new injectors can contribute towards the development of structural interventions targeted at new injectors and their injecting and sex partners in high-risk neighborhoods.