Predicting disease risk from community context and host phenotype: A trait-based approach

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该项目将测试一个人感染传染病的风险是否由宿主个体的少数容易测量的生态特征决定（即，宿主表型），以及作为潜在感染源的其他宿主物种（群落环境）。 将使用多宿主病媒病原体的模型系统进行实验：大麦黄矮病毒、传播它们的蚜虫（昆虫）病媒和20种野草宿主物种。 首先，温室实验将量化这些草种在低和高氮（养分）可用性的表型。 表型将基于一套生理性状进行定量，包括光合作用速率、叶片中营养物质的浓度、叶片生长速率和叶片寿命。 具有高营养浓度的宿主预计也具有高代谢率（包括快速返回或QR表型），而具有低营养浓度的宿主将具有低代谢率（缓慢返回或SR表型）。 温室实验还将测试QR表型是否比SR表型更容易被蚜虫取食，更容易受到蚜虫的感染，并且能够更好地承受感染的负面影响。 田间实验将测试QR表型是否比SR表型经历更大的风险，从其他宿主物种的疾病传播，以及这种风险是否取决于社区环境。 田间试验将测试人类活动的主要结果-增加的养分供应是否会改变疾病风险。 预测疾病风险是一个重要的生态、农业和公共卫生目标。 特别令人关切的是感染多种宿主物种的病媒传播疾病。 例如，西尼罗河病毒主要通过以受感染鸟类（宿主）为食的蚊子（病媒）传播给人类（宿主）。同样，大多数农作物病原体也感染野生植物宿主物种。 了解风险来源将改善对野生和家养动植物以及人类疾病的管理。 该项目将涉及本科生和研究生，其结果将传达给从当地高中生到公共卫生专业人员的公民。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This project will test whether an individual's risk of acquiring an infectious disease is determined by a handful of easily measured ecological traits of the host individual (i.e., host phenotype), and of other host species that are potential sources of infection (community context). Experiments will be conducted using a model system for multi-host vector-borne pathogens: barley yellow dwarf viruses, aphid (insect) vectors that transmit them, and 20 wild grass host species. First, greenhouse experiments will quantify the phenotypes of these grass species at low and high nitrogen (nutrient) availability. Phenotypes will be quantified based on a suite of physiological traits including rate of photosynthesis, concentration of nutrients in leaves, leaf growth rate, and leaf lifespan. Hosts with high nutrient concentrations are expected to also have high metabolic rates (comprising quick-return or QR phenotypes) while hosts with low nutrient concentrations will have low metabolic rates (slow-return or SR phenotypes). Greenhouse experiments will also test whether QR phenotypes are more heavily fed upon by aphids, are more susceptible to infection by feeding aphids, and are better able to withstand the negative impacts of infection than SR phenotypes. Field experiments will test whether QR phenotypes experience greater risk than SR phenotypes of disease transmission from other host species, and whether that risk depends on community context. The field experiments will test whether increased nutrient availability, a major result of human activities, alters disease risk. Predicting risk of disease is a critical ecological, agricultural, and public health goal. Of particular concern are vector-borne diseases that infect multiple host species. For example, West Nile virus is transmitted to humans (hosts) chiefly by mosquitoes (vectors) that fed on infected birds (hosts). Similarly, most pathogens of crops also infect wild plant host species. Understanding sources of risk will improve management of diseases in wild and domestic plants and animals, as well as humans. This project will involve both undergraduate and graduate students, and results will be communicated to citizens ranging from local high school students to public health professionals.