DISSERTATION RESEARCH: Influences of host variation on pathogen prevalence and disease dynamics in free-living communities

媒介传播和人畜共患疾病（如莱姆病、西尼罗河病毒）已成为美国和全球日益关注的公共卫生和野生动物管理问题。最近在疾病生态学方面的研究大大提高了我们对寄生虫和病原体的行为和动力学的理解。虽然有证据表明，一些宿主比其他宿主更容易感染或传播病原体，但大多数描述疾病动态的理论模型都忽略了个体之间的差异。个体差异的来源，如性别、年龄、病原体合并感染状态、既往感染和免疫功能，影响宿主感染的方式。综合群体和个人层面的方法可以更好地描述病原体如何受到宿主的小规模环境和宿主、媒介和病原体的大规模社区的影响，从而更好地评估疾病风险和病原体流行情况。本研究解决了以下问题：1)个体宿主之间的差异如何影响寄生虫负荷和感染概率？2)宿主感染概率的变化如何决定人群和社区水平上病原体的流行？为了解决这些问题，将在蜱虫活动高峰期对蜱虫和小型哺乳动物宿主进行重复采样，并评估宿主和蜱虫的共同感染状况以及宿主的免疫反应。下一代高通量测序将用于分析蜱虫和宿主微生物的共同感染模式。一般的功能性免疫测定和宿主细胞因子谱的详细测量相结合，将用于了解免疫系统如何与媒介和媒介传播感染相互作用。本项目利用生物科学多个领域的技术，研究了从细菌到载体、宿主和环境等多个层面的多样性。这一研究项目的结果可能有助于更好地实地评估人患病媒传播疾病的风险。这项研究的跨学科性质为本科生的研究项目提供了许多机会，从动物行为到媒介和病原体遗传学，使这个项目对广泛的学生来说是令人兴奋的。将为当地DNR、公园和娱乐团体设计有关蜱传疾病和降低风险的教育文献。

Vector-borne and zoonotic diseases (e.g. Lyme Disease, West Nile virus) have become an increased public health and wildlife management concern in the US and globally. Recent research in disease ecology has greatly improved our understanding of the behavior and dynamics of parasites and pathogens. While evidence shows some hosts become infected or transmit pathogens more than others, most theoretical models describing disease dynamics have ignored differences among individuals. Sources of individual variability such as sex, age, pathogen co-infection status, previous infection, and immune function influence how hosts become infected. Integrating population- and individual-level approaches can better describe how pathogens are affected by the small-scale environment of the host and the larger-scale community of hosts, vectors, and pathogens, leading to better assessment of disease risk and pathogen prevalence. This research addresses the following questions: 1) How does variation among individual hosts affect parasite load and probability of infection? 2) How does variation in the probability of host infection determine pathogen prevalence at the population and community level? To address these questions, ticks and small mammal hosts will be repeatedly sampled across the season of peak tick activity, and the co-infection status of hosts and ticks, as well as the host immune response, will be evaluated. Next-generation, high throughput sequencing will be used to analyze tick and host microbial co-infection patterns. A combination of a general, functional immune assay and detailed measurement of host cytokine profiles will be used to inform how the immune system interacts with vectors and vector-borne infection.This project investigates many levels of diversity, from bacterial to vector, host, and environment, using techniques from multiple fields of biological science. The results of this research project may lead to better on the ground assessment of human risk for vector-borne disease. The interdisciplinary nature of this research provides many opportunities for undergraduate research projects, from animal behavior to vector and pathogen genetics, making this project exciting to a broad diversity of students. Educational literature on tick-borne disease and minimizing risk will be designed for local DNR, parks and recreation groups.