Collaborative Research: Community Ecology as a Framework for Understanding Disease Dynamics

尽管在几乎每个群落中都发现了寄生虫，但群落与疾病生态学之间的关系仍然知之甚少。我们的目标是确定物种相互作用和常见环境压力因素影响疾病特性和群落动态的机制。我们的重点宿主是两栖动物，这是一个受到全球保护关注的群体，受到最近出现的传染病的影响。局灶性寄生虫为吸虫（扁虫）、水蛭和细棘虫。它们从蜗牛传播给两栖动物，分别导致与肢体畸形和肾脏损伤相关的死亡。我们的假设是，吸虫传播、相关死亡率和两栖动物适应性将取决于群落组成和非生物压力源。我们将开展调查，以确定两栖动物吸虫感染与湿地及其周围景观的生物和非生物特征之间的关系。我们将使用中生态群落来研究竞争和捕食（生物压力源）、农药和与气候变化相关的条件（非生物压力源）如何独立和联合影响两栖动物的适应性和疾病特性。此外，我们将阐明两栖动物免疫反应与生物和非生物应激源和感染风险之间的关系，通过对我们每个实验的两栖动物进行免疫学分析。最后，我们将为人类改变的环境中吸虫的传播制定预测数学模型。该项目是将社区生态学、免疫学和流行病学结合起来的一项开创性努力，将通过阐明宿主-寄生虫相互作用的一般原则，提高我们预测未来媒介传播疾病暴发的能力。

Despite parasites being found in nearly every community, the relationship between community and disease ecology remains poorly understood. Our goal is to determine the mechanisms by which species interactions and common environmental stressors influence disease properties and community dynamics. Our focal hosts are amphibians, a group of global conservation concern that has been impacted by the recent emergence of infectious diseases. The focal parasites are the trematodes (flatworms) Ribeiroia ondatrae and Echinostoma trivolvis. They are transmitted from snails to amphibians and induce mortality associated with limb deformities and kidney damage, respectively. Our hypothesis is that trematode transmission, associated mortality, and amphibian fitness will depend upon community composition and abiotic stressors. We will conduct surveys to identify relationships among amphibian trematode infections and biotic and abiotic characteristics of wetlands and their surrounding landscape. We will use mesocosm communities to examine how the independent and combined effects of competition and predation (biotic stressors) and pesticides and conditions associated with climate change (abiotic stressors) influence amphibian fitness and disease properties. Additionally, we will elucidate the relationships among amphibian immune responses and biotic and abiotic stressors and infection risk by conducting immunological assays on amphibians from each of our experiments. Finally, we will formulate predictive mathematical models for the spread of trematodes in human-altered environments. This project represents a pioneering effort in the integration of community ecology, immunology, and epidemiology that will improve our ability to forecast future vector-borne disease outbreaks by shedding light on general principles governing host-parasite interactions.