Drug tourism to Mexico: Impact of Mexicos new drug law on HIV-HCV-TB in US IDUs

描述（由申请人提供）：拟议的5年流行病学研究的目标是评估墨西哥新毒品法对美国注射毒品使用者（IDUs）行为和疾病发生率的影响。2009年8月，墨西哥颁布了一项有争议的法律，将拥有个人大小数量的毒品（包括海洛因、可卡因、甲基苯丙胺和大麻）合法化。美国加利福尼亚州圣地亚哥和墨西哥不列颠哥伦比亚省蒂华纳的姐妹城市共享世界上最繁忙的陆地边境，拥有近400万居民。通过与加州大学圣地亚哥分校和合作伙伴在蒂华纳的研究合作，我们发现：i）蒂华纳的药物使用和艾滋病毒流行率增加; ii）丙型肝炎病毒（HCV）和M.结核病（Mtb）感染的注射吸毒者在蒂华纳与圣地亚哥;和，iii）注射在墨西哥报告的21%的注射吸毒者在圣地亚哥。圣迭戈注射吸毒者前往墨西哥的“毒品旅游”可能是墨西哥放松毒品法的意外后果，可能增加他们感染丙型肝炎病毒、结核病和艾滋病毒的风险。本流行病学研究的目的是：1）确定圣地亚哥注射吸毒者在社会人口学、行为和健康状况方面的差异，2）描述圣地亚哥注射吸毒者对墨西哥毒品政策的知识、态度和经验的变化，并评估其对墨西哥注射决策的影响;和3）确定在墨西哥注射的圣地亚哥注射吸毒者是否增加了发生HCV和Mtb感染的风险，并确定感染的风险因素。为了实现这些目标，我们将使用混合方法的设计，涉及定量和定性数据收集。定量方法包括在圣地亚哥通过应答者驱动抽样招募750名注射吸毒者队列，进行半年一次的行为评估和24个月随访期间的HIV、HCV和Mtb感染血清学检测。将使用标准实践对血清进行HIV和HCV抗体检测;将通过QuantiFERON TB-Gold检测试剂盒检测Mtb感染。定性方法包括在每次评估访问后选择20名参与者（共计100人）进行深入访谈，以便：㈠探讨在对定量数据进行初步分析时得出的新结论; ㈡确定可在定量评估之外进行调查的新领域;以及iii）通过在定性访谈中向研究参与者提供定量研究结果以供解释，评估定量研究结果的有效性。使用定性和定量数据的迭代过程，以告知方法和解释每种方法的结果，有利于全面理解的概念模型，描述墨西哥的新法律将如何影响注射吸毒者在圣地亚哥的行为和健康结果。这项研究符合NIDA的优先事项，支持对艾滋病毒/艾滋病合并症（包括HCV和结核病）的流行病学研究，以及在弱势人群中预防艾滋病毒。这项研究利用了一个罕见的自然实验来评估反对毒品政策对相互关联的边境社区的影响，并将为未来的政策提供重要的见解。 公共卫生相关性：注射毒品使用者（IDUs）不成比例地受到艾滋病毒，丙型肝炎和结核病的影响，最近认识到这些疾病在蒂华纳，墨西哥-圣地亚哥，加利福尼亚州的姐妹城市-表明，如果没有有效的干预措施，疾病的进展和传播率将增加。2010年8月，墨西哥颁布了新的立法，将拥有个人数量的麻醉药品非刑事化（例如，甲基苯丙胺、海洛因、可卡因和大麻），人们担心这将鼓励更多的美国注射吸毒者前往墨西哥购买和使用毒品。在与NIDA资助的研究，将评估法律的影响注射吸毒者在蒂华纳平行，我们将进行纵向队列研究，以检查法律的影响注射吸毒者的行为和疾病风险在圣地亚哥谁可以很容易地越过边境，从墨西哥。

DESCRIPTION (provided by applicant): The goal of the proposed 5-year epidemiologic study is to assess the impact of Mexico's new drug laws on behaviors and disease incidence among injection drug users (IDUs) in the U.S. In August, 2009, Mexico enacted a controversial law decriminalizing possession of personal-sized quantities of drugs including heroin, cocaine, methamphetamine and cannabis. The sister-cities of San Diego, CA, USA and Tijuana, BC, Mexico share the world's busiest land border crossing and are home to nearly 4 million residents. Through research collaborations with the University of California, San Diego and partners in Tijuana, we found: i) increasing drug use and HIV prevalence in Tijuana; ii) dramatically higher prevalence of hepatitis C virus (HCV) and M. tuberculosis (Mtb) infections among IDUs in Tijuana versus San Diego; and, iii) injecting in Mexico reported by 21% of IDUs in San Diego. "Drug tourism" to Mexico among San Diegan IDUs may be an unintended consequence of Mexico's relaxed drug laws and could increase their risk for HCV, Mtb and HIV infections. This epidemiologic study aims to: 1) identify sociodemographic, behavioral, and health status differences between IDUs in San Diego who do and do not inject in Mexico; 2) describe changes in San Diegan IDUs' knowledge, attitudes, and experiences related to Mexican drug policies and assess their influences on decisions about injecting in Mexico; and 3) determine whether San Diegan IDUs who inject in Mexico are at increased risk for incident HCV and Mtb infection and identify risk factors for infection. To achieve these aims, we will use a mixed-methods design involving quantitative and qualitative data collection. Quantitative methods include recruiting a cohort of 750 IDUs in San Diego via respondent driven sampling for semi-annual behavioral assessments and serologic testing for HIV, HCV, and Mtb infections over 24 months of follow-up. HIV and HCV antibody testing will be performed on serum using standard practices; Mtb infection will be detected by QuantiFERON TB-Gold assay. Qualitative methods involve selecting 20 participants after each assessment visit (total=100) for in-depth interviews that will be used to: i) explore novel findings that emerge in preliminary analysis of the quantitative data; ii) identify new areas of inquiry for addition to the quantitative assessments; and iii) assess the validity of quantitative findings by presenting them for interpretation to study participants in qualitative interviews. The iterative process of using qualitative and quantitative data to inform methods and interpret findings of each approach facilitates a comprehensive understanding of the conceptual model describing how Mexico's new law will impact the behaviors and health outcomes of IDUs in San Diego. This study meets NIDA priorities supporting epidemiologic research on HIV/AIDS co-morbidities including HCV and tuberculosis, and the prevention of HIV among vulnerable populations. This study exploits a rare natural experiment to evaluate the impact of opposing drug policies on interconnected, bordering communities, and will provide important insights for future policies. PUBLIC HEALTH RELEVANCE: Injection drug users (IDUs) are disproportionately affected by HIV, hepatitis C, and tuberculosis, and, the recently recognized convergence of these diseases in Tijuana, Mexico-sister city to San Diego, CA- suggests that progression of disease and rates of transmission will increase without effective interventions. In August, 2010 Mexico enacted new legislation decriminalizing possession of personal-size quantities of narcotic drugs (e.g., methamphetamine, heroin, cocaine, and cannabis), which it is feared will encourage more U.S. IDUs to visit Mexico to buy and use drugs. In parallel with a NIDA-funded study that will assess the law's impact on IDUs in Tijuana, we will conduct a longitudinal cohort study to examine the law's impact on the behaviors and disease risks among IDUs in San Diego who can readily cross the border to and from Mexico.