CAREER: Intraspecific variation in pathogen load in virus-infected birds: role of extrinsic and intrinsic factors

在上个世纪，新出现的传染病数量出现了前所未有的增长，对野生和家养动物以及人类种群构成了重大风险。此外，超过60%的人类传染病起源于动物，包括西尼罗河病毒和禽流感病毒，鸟类是其来源。疾病流行病学的一个突出知识缺口是对影响个体传染性变化的因素的理解。该项目有四个主要目标：（1）以美洲知更鸟（Turdus migratorius）为重点物种，测试宿主身体状况的变化如何通过食物限制影响鸟类对西尼罗河病毒的反应。(2)使用全基因组技术，研究基因表达如何介导低致病性禽流感病毒和两种水禽（绿头鸭（Anas platyrhynchos）和蓝翅鸭（A. discors）。(3)开发模拟模型，用实验中收集的数据进行参数化，以研究个体变异对种群水平病原体动态的影响。(4)调整模型，让普通科学的大学非STEM学生了解疾病动力学。 通过用户友好的计算机界面，学生将能够操纵与气候变化和/或其他人为干扰相关的环境压力源，然后跟踪宿主和病原体特异性的疾病结果。实施计算机模拟练习，说明整个学期教授的概念，并允许学生回答相关和发人深省的问题，将改善学生在大班环境中的学习体验。总的来说，这个CAREER项目将增加对病原体载量变化的基础的理解，以及哪些个体可能会排出最高的病原体载量（即“超级排出者”），从而可以开发更现实的流行病学模型，从而产生具有成本效益的，有针对性的预防和控制策略。

In the last century, there has been an unprecedented increase in the number of emerging infectious diseases that pose significant risks to wild and domestic animal and human populations. Moreover, greater than 60% of all human infectious diseases have originated in animals, including West Nile virus and avian influenza virus, for which birds serve as the sources. A prominent knowledge gap in disease epidemiology is an understanding of the factors that influence variation in infectiousness of individuals. This project has four main objectives: (1) Test how variation in host body condition, through food restriction, affects how a bird responds to West Nile virus, using American robin (Turdus migratorius) as a focal species. (2) Use genome-wide technologies to investigate how gene expression mediates variation in viral shedding using low pathogenic avian influenza virus and two species of waterfowl, the mallard (Anas platyrhynchos) and blue-winged teal (A. discors). (3) Develop simulation models that are parameterized with the data collected in experiments to investigate the effects of individual variation on pathogen dynamics at the population level. (4) Adapt the models to allow college, non-STEM students in general sciences to learn about disease dynamics. Through a user-friendly computer interface students will be able to manipulate environmental stressors associated with climate change and/or other anthropogenic disturbances, and then track disease outcomes that are host and pathogen specific. Implementing a computer simulation exercise that illustrates concepts taught throughout the semester and allows students to answer relevant and thought-provoking questions will improve a student's learning experience in the large class environment. Overall this CAREER project will increase the understanding about the basis for variation in pathogen load and also which individuals may shed the highest pathogen loads (i.e. 'supershedders'), allowing development of more realistic epidemiological models that lead to cost-effective, targeted prevention and control strategies.