Once Bitten: Detecting the World's Most Common Vector-Borne Pathogens

描述（由申请人提供）：登革热和疟疾是世界上传播最广泛的媒介传播的人类病原体，世界上一半以上的人口生活在流行地区。这些感染导致非特异性临床表现，其严重程度从自限性发热性疾病到感染性休克和死亡不等。依赖于准确的实验室检查的确诊与患者预后的改善有关。然而，对这些药物的现有诊断测试往往缺乏常规使用所需的灵敏度或性能特征。此外，尽管在流行地区和这些感染的临床表现有重大重叠，但尚未开发出区分登革热和疟疾的多重检测方法。当前应用的目标是利用登革热的敏感诊断测试，以确定与严重疾病相关的患者和病毒因素，进一步划定登革热流行病学在流行地区的范围，并开发基于综合征的登革热和疟疾多重测试。为了实现这些目标，将对尼加拉瓜和津巴布韦患者队列的样本进行研究。将利用因登革热住院的尼加拉瓜儿童，确定预示严重疾病风险增加的病毒载量阈值和患者风险因素。将对诊断为非登革热疾病的2900名尼加拉瓜发热儿童进行单独队列登革热检测，以确定需要进行特定登革热检测的非典型临床综合征。这组患者还将使我们能够确定血清学反应对漏诊登革热感染检测的敏感性。最后，我们开发了一种登革热和疟疾多重检测方法，将用于在津巴布韦的洪得谷研究这些病原体。在过去十年中，该地区的疟疾卷土重来。这项研究将建立在我在斯坦福大学传染病研究期间开始的工作基础上。在过去两年中，我设计并验证了两种实时登革热rt - pcr，这两种方法都被证明比流行的诊断方法更敏感。我现在正在寻求利用这些分析来研究登革热流行病学和病理生理学。其中一项检测是用于泛登革热检测的内部控制RT-PCR，它是上述登革热-疟疾多重检测的起点。我的共同导师包括分子诊断专家Benjamin Pinsky博士和登革热病理生理学和流行病学专家Eva Harris博士。我还组建了一个在全球卫生、流行病学和诊断发展方面具有丰富经验的合作者和顾问团队。斯坦福大学是追求临床导向研究和国际研究的理想环境。虽然我们的实验室包含完成本提案中概述的研究所需的设备，但我仍然可以使用校园内的19个核心设施来解决可能出现的问题。斯坦福大学促进跨学科合作，并为专注于新诊断技术开发的领先学术研究人员和生物技术公司提供机会。该建议还包括位于登革热流行地区（尼加拉瓜马那瓜国家诊断参考中心）和疟疾流行地区（津巴布韦哈拉雷生物医学研究和培训研究所）的两个国际站点。这些站点不仅提供了获得研究登革热和疟疾所需的临床材料的途径，还允许在资源有限的情况下与国际医学专家和能力建设方面进行合作。该提案的预期成果包括：对两个流行地区登革热流行病学的深入了解，对重症登革热临床预测规则的验证，以及对全世界最常见的媒介传播病原体开发近护理多重检测。为追求这些目标而进行的研究代表了我职业发展的下一步，将传染病研究与独立的全球卫生调查员的职业联系起来。我的共同导师和合作者是唯一有资格支持这项研究的人，三个有免费资源的研究地点最大限度地提高了成功的机会。

DESCRIPTION (provided by applicant): Dengue and malaria are the most widespread vector-borne human pathogens worldwide, with over half of the world's population living in endemic areas. These infections result in non-specific clinical manifestations that range in severity from a self-limited febrile illness to septic shock and death. A confirmed diagnosis, which relies on accurate laboratory tests, is associated with improved patient outcomes. Available diagnostic tests for these agents, however, often lack sensitivity or the performance characteristics necessary for routine use. Furthermore, multiplex assays that distinguish between dengue and malaria have not been developed, despite significant overlap in the endemic area and clinical presentation of these infections. The objectives of the current application are to utilize sensitive diagnostic tests for dengue in order to identify patient and vral factors associated with severe disease, further delineate dengue epidemiology in endemic regions, and develop a syndrome-based multiplex test for dengue and malaria. In order to accomplish these objectives, samples from cohorts of patients in Nicaragua and Zimbabwe will be studied. Using Nicaraguan children admitted to the hospital for dengue, viral load thresholds and patient risk factors will be identified that portend an increased risk of severe disease. A separate cohort of 2,900 febrile Nicaraguan children diagnosed with a non-dengue illness will be tested for dengue to identify atypical clinical syndromes that warrant specific dengue testing. This cohort of patients will also allow us to establish the sensitivity of serological responses fo the detection of missed dengue infections. Finally, we have developed a dengue and malaria multiplex test that will be employed in the study of these pathogens in the Honde Valley of Zimbabwe, which has experienced a resurgence of malaria over the past decade. This research will build off of work started during my fellowship in infectious diseases at Stanford University. During the past two years, I have designed and validated two real-time dengue RT-PCRs, which have both proven more sensitive than prevailing diagnostics. I am now seeking to employ these assays to study dengue epidemiology and pathophysiology. One of these tests, an internally con- trolled RT-PCR for pan-dengue detection, served as the starting point for the dengue-malaria multiplex assay mentioned above. My co-mentors for this proposal include experts in molecular diagnostics, Dr. Benjamin Pinsky, and dengue pathophysiology and epidemiology, Dr. Eva Harris. I have also assembled a team of collaborators and consultants with a wealth of experience in global health, epidemiology, and diagnostics development. Stanford University represents an ideal environment for the pursuit of clinically oriented research and international studies. While our laboratory contains the equipment necessary for the completion of the research outlined in this proposal, I will still have access to nineteen core facilities on campus o address questions that may arise. Stanford fosters cross-disciplinary collaborations and provides access to leading academic researchers and biotechnology companies focused on the development of new diagnostics. This proposal also includes two international sites located in areas endemic for dengue (Centro Nacional de Diagnostico y Referencia, Managua, Nicaragua) and malaria (Biomedical Research and Training Institute, Harare, Zimbabwe). These sites not only provide access to the clinical material necessary for the study of dengue and malaria, they allow for collaboration with experts in international medicine and capacity building in resource limited settings. The expected outcomes of this proposal include a refined understanding of dengue epidemiology in two endemic regions, the validation of a clinical prediction rule for severe dengue, and the development of a near-care multiplex assay for the most common vector-borne pathogens worldwide. Research performed in pursuit of these aims represents the next step in my professional development, bridging infectious disease fellowship with a career as an independent global health investigator. My co-mentors and collaborators are uniquely qualified to support this research, and three study sites with complimentary resources maximize the opportunities for success.