Spatio-temporally explicit estimation of R0 for pathogens with environmentally-mediated transmission

环境介导传播病原体的 R0 时空显式估计

• 批准号: 9119040
• 负责人: Jason K Blackburn
• 金额: $ 36.18万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9119040
• 关键词: Anthrax disease; Area; Bacillus anthracis; Behavior; Breathing; Brucellosis; Chronic Wasting Disease; Data Set; Demography; Disease; Environmental Risk Factor; Health; Human; Individual; Infection; Ingestion; Link; Livestock; Mediating; Modeling; Movement; Pattern; Resources; Spatial Distribution; System; Zoonoses; computerized tools; disorder control; high risk; human disease; life history; mathematical methods; novel; pathogen; transmission process

 DESCRIPTION (provided by applicant): Indirect pathogen transmission can be vectored or environmentally-mediated. The latter is the primary mode of infection for a number of important multi-host diseases in wildlife and livestock, including several zoonoses (diseases that spillover into humans) and is explicitly linked to host movements and foraging in areas where the pathogen is maintained in environmental reservoirs. Calculating R0 in such systems requires that we estimate the contribution of each reservoir to new cases. To do this we must unpack the transmission process into its pathogen shedding, environmental persistence, and host contact (pathogen ingestion or inhalation) components. Such contact rates can be characterized from a combination of local host movement and foraging patterns driven by larger-scale seasonal resource selection. Persistent environmental pathogen reservoirs can be modeled as individual, local infectious zones with their own demography and spatial distribution; life history of these zones influence host foraging locally. In this 4-year EEID project, we provide a novel combined geospatial and mathematical approach for estimating R0 for environmentally-mediated transmission. We will then assess efficacies of control strategies impacting different components of the transmission process. Toward this, we propose the following specific aims: Specific Aim 1: Derive functions to describe host-specific contact rates with local infectious zones by quantifying host movement and foraging behavior, characterizing the spatial distribution and demography of local infectious zones, characterizing the environmental factors controlling host foraging and pathogen persistence; Specific Aim 2: Apply these functions to estimating R0 for anthrax (indirect transmission of Bacillus anthracis) using empirical datasets from two regions with active anthrax in free ranging herbivores-contrasting systems with and without disease control; Specific Aim 3: Evaluate the conceptual and practical impact of our novel R0 estimates as related to disease control strategies for wildlife and livestock systems, including those where human disease remains a major threat.

 描述（由申请人提供）：病原体间接传播可以是媒介传播或环境介导的。后者是野生动物和牲畜中许多重要的多宿主疾病的主要感染方式，包括几种人畜共患疾病（蔓延到人类的疾病），并且与宿主在环境储存库中病原体的移动和觅食明显相关。在此类系统中计算 R0 需要我们估计每个水库对新病例的贡献。为此，我们必须将传播过程分解为病原体脱落、环境持久性和宿主接触（病原体摄入或吸入）组成部分。这种接触率可以通过大规模季节性资源选择驱动的当地宿主移动和觅食模式的组合来表征。持久性环境病原体储存库可以建模为具有自己的人口统计和空间分布的单独的局部感染区；这些区域的生活史影响当地宿主的觅食。在这个为期 4 年的 EEID 项目中，我们提供了一种新颖的地理空间和数学组合方法来估计环境介导传播的 R0。然后，我们将评估影响传输过程不同组成部分的控制策略的有效性。为此，我们提出以下具体目标： 具体目标 1：通过量化宿主运动和觅食行为、表征当地感染区的空间分布和人口特征、表征控制宿主觅食和病原体持久性的环境因素，导出描述宿主与当地感染区特定接触率的函数；具体目标 2：使用这些函数来估计炭疽病（炭疽杆菌的间接传播）的 R0，使用来自两个活跃炭疽病区域的经验数据集，在自由放养的食草动物对比系统中进行和不进行疾病控制；具体目标 3：评估我们新的 R0 估计值与野生动物和牲畜系统（包括人类疾病仍然是主要威胁的系统）疾病控制策略相关的概念和实际影响。