Epidemiologic Study on Changing HIV Risks Among FSW-IDUs on the Mexico-US Border

描述（由申请人提供）：在全球范围内，注射毒品的FSW-IDUs （FSW-IDUs）是重要的“桥梁”人群，可以将艾滋病毒/性传播感染传播给一般人群；然而，缺乏减少注射和性行为风险的干预措施。本流行病学研究的总体目标是同时降低墨西哥-美国两个地区FSW-IDUs吸毒者的高危性行为和注射行为。边境城市，其中艾滋病毒流行率最近从2%上升到14%；46%的人至少有一种活跃的性传播感染。我们的具体目标是：目的1)评估行为干预减少FSW-IDUs共用注射器和注射用具的效果。我们假设在主动实验性注射风险降低条件下，fsw - idu将报告：(a)更少接受和分配针头共享；(b)减少共用注射用具；(c)从较安全的来源取得注射器和注射用具。目的2)评价行为干预在持续吸毒的FSW-IDUs中增加安全套使用的效果。我们假设在积极的实验性风险降低条件下，FSW-IDUs将：(a)报告较少的无保护的阴道和肛交；(b)特定性传播感染个案减少。目的3)评估这两种行为干预措施在增加安全套使用和减少共用针头/注射用具方面的联合效果。我们假设，与单独干预相比，这些干预的联合效应将产生更大的风险降低。目标4)确定干预措施中理论上重要的组成部分（即自我效能感、结果预期、态度、意图）在多大程度上代表了主要结果（即性行为和注射相关风险降低）变化的潜在机制。目的5)探讨基于背景特征、环境因素、社会因素和个人因素的a)性风险降低干预和b)注射风险降低干预疗效的亚组差异。为了实现这些目标，我们将招募600名艾滋病毒阴性的fswi注射者（蒂华纳和华雷斯Cd各300名），并将妇女随机分为三个时间相等的组（第一组：注射风险干预和说教性安全性教育；第二组：性风险干预和说教性安全注射教育；第三组：积极注射和性干预）。在每个城市，将采用聚类随机化来减少污染。所有妇女都接受免费性传播感染治疗，并将在4、8和12个月时进行随访。我们的设计允许我们“拆解”干预措施，以确定其组成部分是否在减少注射和/或性风险方面同样有效，或者是否需要更密集的条件来改变艾滋病毒/性传播感染的流行病学，从而对墨西哥和美国具有直接，切实的政策影响。减少外来注射吸毒者艾滋病毒风险的干预措施可能会遏制美墨边境地区迅速蔓延的艾滋病毒流行，并适用于其他资源贫乏的国家。在全球范围内，注射毒品的妇女是可以将艾滋病毒/性传播感染传播给一般人群的重要“桥梁”人群；然而，缺乏减少注射和性行为风险的干预措施。本流行病学研究的总体目标是同时降低墨西哥-美国两个地区FSW-IDUs吸毒者的高危性行为和注射行为。这些城市的艾滋病毒流行率最近急剧上升。据我们所知，这是在任何国家进行的同类研究中的首次测试，其结果与资源受限的环境特别相关。

DESCRIPTION (provided by applicant): Globally, FSWs who inject drugs (FSW-IDUs) are important `bridge' populations that can transmit HIV/STIs to the general population; however, interventions to reduce both their injection and sexual risks are lacking. The overall goal of this epidemiologic study is to simultaneously reduce high risk sexual and injection behaviors among FSW-IDUs in two Mexico-U.S. border cities, among whom HIV prevalence has recently increased from 2% to 14%; 46% had at least one active STI. Our specific aims are: Aim 1) To evaluate the efficacy of a behavioral intervention to decrease sharing of syringes and injection paraphernalia among FSW-IDUs. We hypothesize that FSW-IDUs in the active experimental injection risk reduction condition will report: (a) less receptive and distributive needle sharing; (b) less sharing of injection paraphernalia; (c) obtaining syringes and injection paraphernalia from safer sources. Aim 2) To evaluate efficacy of a behavioral intervention to increase condom use among FSW-IDUs in the context of ongoing drug use. We hypothesize that FSW-IDUs in the active experimental sexual risk reduction condition will: (a) report less unprotected vaginal and anal sex; (b) have fewer incident cases of specific STIs. Aim 3) To evaluate the joint effects of these two behavioral interventions to increase condom use and reduce sharing of needles/injection paraphernalia among FSW- IDUs. We hypothesize that the joint effect of these interventions will generate greater risk reductions compared to either intervention alone. Aim 4) To determine the extent to which theoretically-important components of our interventions (i.e., self-efficacy, outcome expectancies, attitudes, intentions) represent underlying mechanisms of change in primary outcomes (i.e., sexual and injection-related risk reductions). Aim 5) To explore subgroup differences in the efficacy of a) the sexual risk reduction intervention and b) the injection risk reduction intervention based on background characteristics, contextual factors, social factors and intrapersonal factors. To meet these aims, we will recruit 600 HIV-negative FSW-IDUs (300 each in Tijuana and Cd. Juarez) and randomize women to one of three time-equivalent groups (Group 1: injection risk intervention and didactic safer sex education; Group 2: sexual risk intervention and didactic safer injection education; Group 3: Both active injection and sexual interventions). In each city, cluster randomization will be used to minimize contamination. All women receive free STI treatment and will be followed-up at 4, 8 and 12 months. Our design allows us to `unpack' the intervention to determine whether its components are just as effective in reducing injection and/or sexual risks, or if the more intensive conditions are needed to alter the epidemiology of HIV/STIs, thus having direct, tangible policy implications for Mexico and the US. Interventions that reduce HIV risks among FSW-IDUs may curtail the burgeoning HIV epidemic in the U.S-Mexico border region, and have applicability to other resource-poor countries.Globally, FSWs who inject drugs (FSW-IDUs) are important `bridge' populations that can transmit HIV/STIs to the general population; however, interventions to reduce both their injection and sexual risks are lacking. The overall goal of this epidemiologic study is to simultaneously reduce high risk sexual and injection behaviors among FSW-IDUs in two Mexico-U.S. border cities, among whom HIV prevalence has recently increased dramatically. To our knowledge, this is the first study of its kind to be tested in any country, findings from which have particular relevance to resource-constrained environments.