Theoretical Epidemiology, Faculty of Veterinary Medicine, Utrecht University, the Netherlands.
J Theor Biol. 2011 Apr 21;275(1):12-20. doi: 10.1016/j.jtbi.2011.01.032. Epub 2011 Jan 27.
Persistence of an infectious agent in a population is an important issue in epidemiology. It is assumed that spatially fragmenting a population of hosts increases the probability of persistence of an infectious agent and that movement of hosts between the patches is vital for that. The influence of migration on persistence is however often studied in mean-field models, whereas in reality the actual distance travelled can be limited and influence the movement dynamics. We use a stochastic model, where within- and between-patch dynamics are coupled and movement is modelled explicitly, to show that explicit consideration of movement distance makes the relation between persistence of infectious agents and the metapopulation structure of its hosts less straightforward than previously thought. We show that the probability of persistence is largest at an intermediate movement distance of the host and that spatially fragmenting a population of hosts is not necessarily beneficial for persistence.
传染病原体在人群中的持续存在是流行病学中的一个重要问题。人们认为，将宿主种群的空间分割会增加传染病原体持续存在的可能性，而宿主在斑块之间的移动对于这种持续存在至关重要。然而，迁移对持久性的影响通常在平均场模型中进行研究，而在现实中，实际的移动距离可能是有限的，并会影响移动动态。我们使用一个随机模型，其中斑块内和斑块间的动态是耦合的，并且明确地建模了移动，以表明明确考虑移动距离会使传染病原体的持久性与其宿主的集合种群结构之间的关系变得不那么简单。我们表明，宿主的中间移动距离下的持久性概率最大，并且将宿主种群的空间分割不一定有利于持久性。
