Marine infectious disease dynamics and outbreak thresholds: contact transmission, pandemic infection, and the potential role of filter feeders
Marine infectious disease dynamics and outbreak thresholds: contact transmission, pandemic infection, and the potential role of filter feeders
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DOI：
10.1002/ecs2.1286
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发表时间：
2016-04-01
期刊：
影响因子：
2.7
通讯作者：
Hofmann, Eileen E.
中科院分区：
文献类型：
--
作者：
Bidegain, Gorka;Powell, Eric N.;Hofmann, Eileen E.
致病生物可对海洋物种和群落产生重大影响。然而，海洋生态系统中疾病暴发的动力学仍然缺乏陆地系统中常规存在的同等水平的描述、概念理解和建模背景。在这里，我们提出了一个理论基础，从简单的传染病传播模型开发的海洋传染病（MID）的传播建模。这些模型代表了各种宿主-病原体系统的动态，包括海洋系统特有的宿主-病原体系统，其中疾病的传播是通过直接和通过滤食过程与水媒病原体接触来实现的。总体而言，对动物流行病模型的分析集中在相互作用以驱动动物流行病开始和结束的最相关过程上。先验地，具有多步疾病感染的系统（例如，感染-死亡-颗粒释放-过滤-传播）减少了对个体参数的依赖性，导致固有的较慢的传播速率。事实证明并非如此;因此，这些替代传播途径也必须大大增加传播过程的速度。清除者清除死亡的受感染动物可以抑制基于接触和基于水媒病原体的疾病的传播。高度感染的动物，无论是活的还是死的，都有能力将大量的感染性元素释放到水体中，使它们能够被悬浮饲养者利用，这导致这种疾病具有高度传染性，只有一个非常小的“低丰度避难所”。在这些系统中，病原体的身体负荷以及宿主组织或水柱中病原体的释放和去除速率之间的相对重要性变得至关重要。两个过程具有抑制动物流行病的潜在后果。第一，海底易感种群上方的大量水可以作为病原体的汇。其次，与接触性疾病模型不同，在接触性疾病模型中，人群中易感个体数量的增加会增加传播和动物流行病发展的可能性，而大量滤食性动物可以通过感染性颗粒的过度过滤来降低这种可能性。
Disease-causing organisms can have significant impacts on marine species and communities. However, the dynamics that underlie the emergence of disease outbreaks in marine ecosystems still lack the equivalent level of description, conceptual understanding, and modeling context routinely present in the terrestrial systems. Here, we propose a theoretical basis for modeling the transmission of marine infectious diseases (MIDs) developed from simple models of the spread of infectious disease. The models represent the dynamics of a variety of host-pathogen systems including those unique to marine systems where transmission of disease is by contact with waterborne pathogens both directly and through filter-feeding processes. Overall, the analysis of the epizootiological models focused on the most relevant processes that interact to drive the initiation and termination of epizootics. A priori, systems with multi-step disease infections (e.g., infection-death-particle release-filtration-transmission) reduced dependence on individual parameters resulting in inherently slower transmissions rates. This is demonstrably not the case; thus, these alternative transmission pathways must also considerably increase the rates of processes involved in transmission. Scavengers removing dead infected animals may inhibit disease spread in both contact-based and waterborne pathogen-based diseases. The capacity of highly infected animals, both alive and dead, to release a substantial number of infective elements into the water column, making them available to suspension feeders results in such diseases being highly infective with a very small "low-abundance refuge". In these systems, the body burden of pathogens and the relative importance between the release and the removal rate of pathogens in the host tissue or water column becomes paramount. Two processes are of potential consequence inhibiting epizootics. First, large water volumes above the benthic susceptible populations can function as a sink for pathogens. Second, unlike contact-based disease models in which an increase in the number of susceptible individuals in the population increases the likelihood of transmission and epizootic development, large populations of filter feeders can reduce this likelihood through the overfiltration of infective particles.