Sit-and-wait pathogens: Consequences of heterogeneity in pathogen exposure dynamics for environmentally persistent pathogens

静坐等待病原体：环境持久性病原体的病原体暴露动态异质性的后果

• 批准号: 10813429
• 负责人: Joseph Hoyt
• 金额: $ 45.68万
• 依托单位: VIRGINIA POLYTECHNIC INST AND ST UNIV
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10813429
• 关键词: Affect; Behavior; Biological Process; Biology; Communicable Diseases; Complex; Data; Disease; Disease Outbreaks; Disease Outcome; Dose; Ecology; Environment; Epidemic; Event; Evolution; Frequencies; Health; Heterogeneity; Human; Infection; Interdisciplinary Study; Microbiology; Modeling; Probability; Research; Role; Route; Snakes; System; Variant; Virulence; Work; experimental study; exposure route; field study; infection risk; infectious disease evolution; insight; mathematical model; pathogen; pathogen exposure; pathogenic fungus; success; transmission process

Transmission is a fundamental component of host-pathogen systems. Despite complex biological processes interacting to determine whether a pathogen successfully infects a host, transmission parameters often assume a constant per-contact transmission probability. Factors that can influence risk of infection include the frequency of exposures, duration of a contact, and dose acquired during an interaction, which are collectively referred to as transmission determinants. These determinants of infection can vary among hosts and between routes of transmission (e.g. direct and indirect) and have profound effects on disease dynamics. Ultimately, a mechanistic understanding of how heterogeneity in transmission probabilities among exposure events contributes to disease dynamics remains an important outstanding question in the ecology and evolution of infectious diseases. Here we seek to elucidate how factors determining transmission success influence the probability of acquiring infection, epidemic dynamics, and pathogen evolution. Specifically, we will investigate how transmission determinants (pathogen dose, contact duration, and contact frequency) vary among exposure routes (direct and indirect) and ultimately contribute to the dynamics of an emerging multi-host disease of snakes. Snake fungal disease (SFD) is caused by, Ophidiomyces ophidiicola, which is an environmentally persistent fungal pathogen that, to date, has been documented in more than 42 species of wild snakes on three continents, and has contributed to the severe declines of several species. O. ophidiicola is transmitted through direct and indirect contacts, and the behavior of snake species affected by SFD naturally vary along an exposure duration and contact intensity gradient, making this an ideal system for understanding the effects of variation in exposure events on disease dynamics. This work will highlight important mechanisms that contribute to variation in snake declines, and more broadly, provide insight into the theoretical underpinnings and profound effects that factors determining successful transmission can have on infectious disease outbreaks. This proposal will leverage our recent advances in this multi-host system and use a combination of field, experimental, and modeling approaches to provide critical insight into how the dynamics of exposure events have cascading effects on infectious disease.

传播是宿主-病原体系统的基本组成部分。尽管生物体复杂 相互作用以确定病原体是否成功感染宿主、传播的过程 参数通常假设每次接触的传输概率恒定。影响风险的因素 感染包括接触频率、接触持续时间以及接触期间获得的剂量 相互作用，统称为传输决定因素。这些感染的决定因素 可能因主机和传播途径（例如直接和间接）而异，并且具有深远的影响 对疾病动态的影响。最终，对传输中的异质性如何产生机械性的理解 暴露事件之间的概率对疾病动态的影响仍然是一个重要的突出问题 传染病的生态学和进化问题。在这里，我们试图阐明因素如何 确定传播成功与否影响感染概率、流行病 动力学和病原体进化。 具体来说，我们将研究传播的决定因素（病原体剂量、接触持续时间和 接触频率）因暴露途径（直接和间接）而异，并最终导致 一种新出现的蛇多宿主疾病的动态。蛇真菌病（SFD）是由以下原因引起的： Ophidiomyces ophidiicola 是一种环境持久性真菌病原体，迄今为止， 据记录存在于三大洲超过 42 种野生蛇中，并导致了严重的 几个物种的衰退。 O. ophidiicola 通过直接和间接接触传播， 受 SFD 影响的蛇类行为自然会随着暴露时间和接触强度而变化 梯度，使其成为了解曝光事件变化对 疾病动态。这项工作将强调导致蛇变异的重要机制 更广泛地说，提供了对理论基础和深远影响的深入了解 决定成功传播的因素可能对传染病的爆发产生影响。 该提案将利用我们在多主机系统方面的最新进展，并结合使用 现场、实验和建模方法，提供关于暴露动态如何变化的重要见解 事件对传染病具有连锁效应。