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吸毒者（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的注射吸毒者中艾滋病毒流行率迅速上升，而其他城市的注射吸毒者中艾滋病毒流行率保持低水平和稳定，尽管注射风险很高。艾滋病毒在注射吸毒者中的流行已经有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广。共用注射器和无保护的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可能会显著导致艾滋病毒传播的差异，那就是注射吸毒者使用的注射器类型。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过程中的一步。迄今为止，我们已经通过证明高死区注射器（HDSSs）在使用和冲洗后保留的血液比低死区注射器（LDSSs）多1000多倍，从生物学上讲，这种类型的注射器可能在艾滋病毒传播中发挥作用是合理的。我们将共用HDSSs的历史与流行的艾滋病毒和丙型肝炎病毒感染联系起来，并建立了数学模型，表明如果使用HDSSs的注射吸毒者少于10%，那么与注射相关的艾滋病毒流行病可能不会在城市发生。下一步是收集实证数据来验证这一发现。需要进行大型的多地点纵向艾滋病毒发病率研究，从各个注射吸毒者收集他们正在使用的注射器类型的数据，以便在注射吸毒者中建立艾滋病毒感染与艾滋病毒感染之间的因果关系。然而，这些研究需要大量的时间和金钱投入。因此，我们建议开展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感染率高的城市和注射吸毒者中艾滋病毒感染率低的城市。我们将设法获得有关这些城市中注射吸毒者使用的注射器类型的信息。拟议的研究有可能以最小的投资获得极有价值的数据。拟议研究的具体目的是：比较注射吸毒者中艾滋病毒感染率高（每年30%）或增加（每年5%，持续3年）的城市中注射吸毒者使用的注射器类型与匹配对照组中艾滋病毒感染率低且稳定（<5%，持续5年）的城市中注射吸毒者使用的注射器类型。如果我们发现HDSSs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，以更好地描述因果推论，包括性传播的作用。

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.