The Role of Dead Space Syringes in HIV Epidemics Amount IDU's - Drug Abuse Aspect

描述（由申请人提供）：艾滋病毒继续在世界许多国家的注射毒品使用者（IDUs）中传播。近年来，东欧、俄罗斯联邦、印度、中国和亚洲其他地区的城市注射吸毒者中艾滋病毒流行率迅速上升，而在其他城市，尽管注射风险很高，但注射吸毒者中艾滋病毒流行率仍然较低且稳定。艾滋病毒在注射吸毒者中流行已经25年了，研究人员仍然不知道为什么这种病毒在某些地方比其他地方传播得更快。共用注射器和无保护性行为的简单比率并不能解释不同程度的艾滋病毒传播。一个被广泛忽视的因素是注射吸毒者使用的注射器类型，这可能是造成艾滋病毒传播差异的重要原因。拟议的研究是评估注射器类型在注射吸毒者中艾滋病毒流行中的作用的过程中的一个步骤。到目前为止，我们已经确定，这是生物学上合理的，注射器的类型可能在艾滋病毒传播中发挥作用，证明高死腔注射器（HDSS）保留超过1,000倍的血液后，使用和冲洗比低死腔注射器（LDSS）保留。我们已经将共享HDSS的历史与流行的HIV和HCV感染联系起来，并且我们已经开发了数学模型，表明如果少于10%的注射吸毒者使用HDSS，则城市中可能不会发生注射相关的HIV流行病。下一步是收集经验数据来验证这一发现。需要进行大型多地点纵向艾滋病毒发病率研究，收集注射吸毒者个人使用的注射器类型的数据，以确定注射吸毒者中HDSS与艾滋病毒感染之间的因果关系。然而，这些研究将需要大量的时间和金钱投资。因此，我们建议进行一项小型探索性研究，以确定欧洲、俄罗斯和亚洲注射吸毒者中艾滋病毒流行率高的城市和注射吸毒者中艾滋病毒流行率低的城市。我们会搜集这些城市注射吸毒者使用的针筒种类的资料。拟议的研究有可能以最少的投资获得极有价值的数据。拟议研究的具体目的是：将注射吸毒者中艾滋病毒流行率高（&gt;30%）或正在增加（&gt;3年，每年&gt;5%）的城市中注射吸毒者使用的注射器类型与艾滋病毒流行率低和稳定的城市（5年）中注射吸毒者使用的注射器类型进行比较<5% for >。如果我们发现HDSS的使用与HIV流行之间存在生态关联，我们将提出更大规模的研究，目的是更好地描述因果推断，包括性传播的作用。 公共卫生相关性：本项目所获得的信息可能会大大增加我们对注射毒品使用者中艾滋病毒传播的了解。如果我们发现注射吸毒者使用的注射器类型会影响艾滋病毒的传播，这可能会导致相对直接的干预措施，从而大大减少艾滋病毒在这一高危群体中的传播。这反过来又可以减少艾滋病毒从注射吸毒者向一般人群的性传播。

DESCRIPTION (provided by applicant): HIV continues to spread among injecting drug users (IDUs) in many countries around the world. In recent years, cities in Eastern Europe, the Russian Federation, India, China, and other parts of Asia have experienced rapid increases in HIV prevalence among IDUs, while HIV prevalence has remained low and stable among IDUs in other cities despite high levels of injecting risk. Twenty-five years into the HIV epidemic among IDUs, researchers still do not really know why the virus spreads more in some places than others. Simple rates of syringe sharing and unprotected sex do not account for varying degrees of HIV transmission. One widely overlooked factor that could significantly contribute to these differences in HIV spread is the type of syringes that IDUs are using. The proposed study represents one step in the process of assessing the role of syringe type in HIV epidemics among IDUs. To date, we have established that it is biologically plausible that the type of syringe may play a role in HIV transmission by demonstrating that high dead-space syringes (HDSSs) retain over 1,000 times more blood after use and rinsing than low dead-space syringes (LDSSs) retain. We have linked a history of sharing HDSSs with prevalent HIV and HCV infection, and we have developed mathematical models that suggest injection-related HIV epidemics may not occur in cities, if fewer than 10% of IDUs are using HDSSs. The next step is to collect empirical data to test this finding. Large multisite longitudinal HIV incidence studies that collect data from individual IDUs on the types of syringes that they are using will be needed to establish a causal relationship between HDSSs and HIV infection among IDUs. However, these studies would require a considerable investment in time and money. Thus, we propose to conduct a small exploratory study to identify cities in Europe, Russia, and Asia where HIV prevalence among IDUs is high and cities where HIV prevalence among IDUs is low. We will seek to obtain information on the types of syringes that IDUs are using in these cities. The proposed study has the potential for yielding extremely valuable data for minimal investment. The specific aim of the proposed study is: To compare the types of syringes used by IDUs in cities where HIV prevalence among IDUs is high (>30%) or increasing (>5% per year for >3 years) with the types of syringes that IDUs are using in a matched comparison group of cities with low and stable HIV prevalence (<5% for >5 years). Should we find an ecological association between use of HDSSs and HIV prevalence, we will propose larger studies with the purpose of better delineating causal inference, including the role for sexual transmission. PUBLIC HEALTH RELEVANCE: The information obtained in this project may substantially increase our knowledge of HIV transmission among injecting drug users (IDUs). If we find that the types of syringes used by IDUs influence HIV transmission, this could lead to relatively straightforward interventions that could substantially reduce HIV transmission in this high risk group. This in turn could reduce sexual transmission of HIV from IDUs to the general population.