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 节肢动物传播病毒的爆发，例如登革热（DENV）和Chikungunya（Chikv）病毒， 证明这些新兴/重新出现对健康的健康威胁的巨额成本和健康负担 发展和发达的世界。在撒哈拉以南非洲，这些疾病的常规被动监测 鉴于误诊的可能性很高和未知水平，仅检测其影响的一小部分 跨不同景观和不同易感人群的传播。已知和未知 昆虫学，环境和行为因素在不同栖息地中差异地驱动传播。我们 假设由于DENV和CHIKV引起的人类疾病的重大负担未被发现 临床环境，导致预防机会错过机会，并增加了大量风险 扩展暴发。初步数据表明，肯尼亚儿童和成人经常暴露于 尽管急性弧病毒感染很少 在此环境中诊断。我们的目标是评估与DENV有关的人类疾病的真正负担 菌株1-4和整个肯尼亚的CHIKV，然后确定病毒循环的驱动因素，估计 爆发启动的阈值，并提供改进的爆发风险评估。我们将调查 CHIKV和DENV1-4在肯尼亚的两个区域的传播，代表异质程度 城市化，风景，气候和人口各不相同。使用几种新颖的方法，我们解决 以下目的：1）量化CHIKV和DENV1-4引起的人类感染和疾病的发生率 并确定它们对急性发热疾病的相对贡献； 2）测量chikv和denv1-的水平 4艾德斯蚊子媒介和非人类灵长类动物的循环，并估计 肯尼亚的人类媒介接触； 3）检测和预测chikv的空间和时间模式 通过整合人类流通的数据（AIM 1）和 矢量（AIM 2）与原位和使用卫星收集的环境和天气/气候数据 图像。这项研究涉及MSAMBWENI（沿海）和Kisumu（肯尼亚西部）的同伙， 全年都有arboviruses的传播，并基于10年的协作 纵向研究。方法论包括分析定义明确的昆虫学之间的关系， 病毒和蚊子暴露的临床，流行病学和气候发现以及免疫生物标志物。 这些研究将填补有关当地栖息地以及Chikv和Denv持续性以及 在流行期间和流行期间有助于持久性的因素 时期。这些数据还将回答有关严重发烧中弧病毒病因的基本问题 高危人群中的综合征，同时提供了更好的相关疾病负担和长期估计 术语后遗症。