The Burden of Chikungunya and Dengue Transmission, Infection and Disease in Kenya

肯尼亚基孔肯雅热和登革热传播、感染和疾病的负担

• 批准号: 9066231
• 负责人: Angelle Desiree LaBeaud
• 金额: $ 32.53万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-05 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9066231
• 关键词: Burden; Chikungunya; Dengue; Transmission; Infection

PROJECT ABSTRACT Outbreaks of arthropod-borne viruses, such as dengue (DENV) and chikungunya (CHIKV) viruses, demonstrate the substantial cost and health burden of these emerging/re-emerging health threats to the developing and developed world. In sub-Saharan Africa, routine passive surveillance for these diseases detects only a fraction of their impact, given the high probability of misdiagnosis and unknown levels of transmission across different landscapes and within different susceptible populations. Known and unknown entomologic, environmental, and behavioral factors differentially drive transmission in different habitats. We hypothesize that a significant burden of human disease due to DENV and CHIKV is undetected in the clinical setting, leading to missed opportunities for prevention and heightened risk for large- scale outbreaks. Preliminary data demonstrate that Kenyan children and adults are frequently exposed to DENV and CHIKV, both between and during known outbreaks, although acute arboviral infections are rarely diagnosed in this setting. Our objectives are to assess the true burden of human disease related to DENV strains 1-4 and for CHIKV across Kenya, and then to determine the drivers of viral circulation, estimate the thresholds for outbreak initiation, and provide improved outbreak risk assessment. We will investigate transmission of CHIKV and DENV1-4 in two regions of Kenya that represent heterogeneous degrees of urbanization with varied landscape, climate, and populations. Using several novel approaches, we address the following aims: 1) Quantify the incidence of human infection and disease due to CHIKV and DENV1-4 and determine their relative contribution to acute febrile illness; 2) Measure the level of CHIKV and DENV1- 4 circulation in Aedes mosquito vectors and non-human primate reservoirs and estimate the amount of human-vector contact in Kenya; and 3) Detect and predict spatial and temporal patterns of CHIKV and DENV transmission in rural and urban settings by integrating data on circulation in humans (Aim 1) and vectors (Aim 2) with environmental and weather/climate data collected both in situ and using satellite imagery. This research involves cohorts in and near Msambweni (coastal) and Kisumu (western), Kenya, where there is year-round transmission of arboviruses, and is based on 10 years of collaborative longitudinal studies. Methodologies include analyses of the relationship between well-defined entomologic, clinical, epidemiologic, and climatologic findings and immune biomarkers of virus and mosquito exposure. These studies will fill knowledge gaps about the persistence of CHIKV and DENV in local habitats and the factors that contribute to persistence during inter-epidemic periods and to regional variation during epidemic periods. The data will also answer fundamental questions about arboviral etiologies in severe fever syndromes among at-risk populations while providing better estimates of related disease burden and long- term sequelae.

项目摘要 节肢动物传播的病毒，如登革热病毒和基孔肯雅病毒的爆发， 证明这些新出现/重新出现的健康威胁给人们带来的巨大成本和健康负担， 发展中国家和发达国家。在撒哈拉以南非洲，对这些疾病的常规被动监测 由于误诊的可能性很高，而且诊断水平未知， 在不同景观和不同易感人群中传播。已知和未知 昆虫学、环境和行为因素在不同生境中不同地驱动传播。我们 假设由于DENV和CHIKV引起的人类疾病的显著负担未在 临床环境，导致错过预防机会，增加了大- 大规模爆发初步数据显示，肯尼亚儿童和成人经常接触到 DENV和CHIKV，两者之间和期间已知的爆发，虽然急性虫媒病毒感染很少 在这种情况下确诊。我们的目标是评估与DENV相关的人类疾病的真实负担 菌株1-4和肯尼亚的CHIKV，然后确定病毒循环的驱动因素，估计 爆发启动阈值，并提供改进的爆发风险评估。我们将调查 CHIKV和DENV 1 -4在肯尼亚两个地区的传播，代表了不同程度的 城市化与不同的景观，气候和人口。使用几种新的方法，我们解决 1）量化由于CHIKV和DENV 1 -4引起的人类感染和疾病的发生率 并确定它们对急性发热性疾病的相对贡献; 2）测量CHIKV和DENV 1 - 1的水平， 4在伊蚊病媒和非人灵长类宿主中的循环，并估计 肯尼亚人-病媒接触;以及3）检测和预测CHIKV的空间和时间模式， 通过整合人体内传播数据在农村和城市环境中传播DENV（目标1）， 矢量（目标2），包括现场和利用卫星收集的环境和天气/气候数据 意象这项研究涉及肯尼亚Msambweni（沿海）和基苏穆（西部）及其附近的队列， 那里全年都有虫媒病毒的传播， 纵向研究。方法学包括分析定义明确的昆虫学， 临床、流行病学和气候学发现以及病毒和蚊子暴露的免疫生物标志物。 这些研究将填补关于CHIKV和DENV在当地栖息地的持久性以及 在两次流行病期间造成持续性和在流行病期间造成区域差异的因素 时期这些数据还将回答关于严重发热的虫媒病毒病因学的基本问题 综合征，同时提供更好的估计相关疾病负担和长期 长期后遗症。