RUI: Linking Ecology, Behavior, and Immunology to Spatio-Temporal Variation in Helminth Transmission

寄生虫经常在空间中不均匀地传播，在那里，一些宿主种群几乎没有寄生虫，而另一些宿主种群感染严重。这种模式很常见，但仍然知之甚少，对准确预测和管理疾病构成了相当大的障碍。对于生活周期复杂或在不同寄主物种之间迁徙的寄生虫来说，情况尤其如此。这包括许多寄生虫(蠕虫)，它们感染了全世界20多亿人，并导致牲畜患上严重疾病，但历史上对它们的研究还不够充分。该项目将经验数据与数学模型联系起来，以了解和预测每个寄主物种内的行为、免疫学和生态如何影响寄生虫跨空间和跨时间的传播。这项研究的重点是一种经过充分研究的绦虫系统，该系统感染淡水湖中的食鱼鸟类(龙)、桡足类和三刺鱼。通过整合所有三个宿主和寄生虫本身的实地研究、实验室实验、遗传研究和数学模型，该项目提供了对复杂生活史寄生虫传播的详细了解，并建立了一个可应用于其他寄生虫的建模工具包。为了分享这项工作，研究人员建立了一个艺术-科学合作项目，让本土艺术家和一名理科新闻专业的学生参与进来，制作一个专注于这个项目的巡回展览。研究也通过基于课程的本科生研究体验纳入课堂，这是一门跨学科的本科课程，专注于艺术和科学之间的联系，是高中的暑期科学计划，并通过出版的教案广泛提供。寄生虫传播是由生态、行为和免疫因素的复杂相互作用形成的，但我们对这些因素如何相互作用及其对疾病流行的相对影响的理解仍然支离破碎。该项目根据经验数据开发了一个通用框架，用于了解和预测这些不同的过程如何在多个宿主内运行，并影响寄生虫在空间和时间上的传播和分布。这项工作解决了四个主要问题：(1)寄生虫暴露(剂量-反应)和免疫对传播动力学的相对贡献是什么？(2)暴露和免疫对环境变化，即资源和宿主种群结构的敏感性如何？(3)寄生虫的丰度在多大程度上是由当地因素或寄生虫传播的景观模式驱动的？(4)寄生虫的不均匀分布更多地是由第一、第二或第三宿主的特征驱动的？使用模型绦虫系统，S.solidus，这项研究开发和应用尖端的统计和数学方法，以及对跨越多个生物组织水平的大型时间和空间数据集的全局敏感性分析。这个项目建立在我们对三刺鱼寄主的充分研究的基础上，并填补了该系统中其他两种寄主(翼足类和桡足类)的重要缺失信息。这项研究产生了一个通用但机械的建模框架，以更好地了解该系统中的传播，并为其他复杂生命周期寄生虫的工作提供信息。该项目得到了环境生物学部门、综合组织系统部门和数学科学部门的支持。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Parasites are often spread unevenly across space, where some host populations have few parasites and others are heavily infected. This pattern is common, but still poorly understood and poses a considerable barrier to accurately predicting and managing diseases. This is especially true for parasites that have complex life cycles or move between different host species. This includes many parasitic worms (helminths), which infect over two billion people worldwide and cause serious disease in livestock, yet have been historically understudied. This project connects empirical data with mathematical models to understand and predict how behavior, immunology, and ecology within each host species shapes parasite transmission across space and through time. This research focuses on a well-studied tapeworm system which infects fish-eating birds (Loons), copepods, and threespine stickleback fish in freshwater lakes. By integrating field studies, laboratory experiments, genetic studies, and mathematical models across all three hosts and the parasite itself, this project provides a detailed understanding of the transmission of a complex-life cycle parasite and builds a modeling toolkit that can be applied to other parasites. To share this work, the investigators have developed an art-science collaboration involving indigenous artists and a science journalism student to produce a traveling exhibition focused on this project. Research is also being incorporated into the classroom through a course-based undergraduate research experience, an interdisciplinary undergraduate course focused on the connections between art and science, a high school summer science program, and is being made broadly available through published lesson plans.Parasite transmission is shaped by a complex interplay of ecological, behavioral, and immunological factors, yet our understanding of how these factors interact and their relative impacts on disease prevalence across scales remains fragmented. The project develops a general framework, informed by empirical data, for understanding and predicting how these different processes operate within multiple hosts and shape parasite transmission and distribution across space and time. This work addresses four main questions: (1) What are the relative contributions of parasite exposure (a dose-response) versus immunity on transmission dynamics? (2) How sensitive are exposure and immunity to environmental variation, namely resources and host population structure? (3) To what extent is parasite abundance driven by local factors or landscape-level patterns of parasite dispersal? (4) Is the uneven distribution of parasites driven more by traits of the first, second, or tertiary host? Using the model tapeworm system, S. solidus, this research develops and applies cutting-edge statistical and mathematical approaches and a global sensitivity analysis to large temporal and spatial datasets spanning multiple levels of biological organization. This project builds on our knowledge of the well-studied threespine stickleback host and filling in important missing information for the other two hosts in this system (loons and copepods). This research produces a general, yet mechanistic, modeling framework to better understand transmission in this system, as well as inform work with other complex life cycle parasites.This project is supported by the Division of Environmental Biology, Division of Integrative Organismal Systems, and Division of Mathematical Sciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.