Department of Chemistry, University of Cambridge, Cambridge, UK.
J R Soc Interface. 2010 Jul 6;7(48):1083-92. doi: 10.1098/rsif.2009.0475. Epub 2010 Jan 14.
One of the challenges in epidemiology is to account for the complex morphological structure of hosts such as plant roots, crop fields, farms, cells, animal habitats and social networks, when the transmission of infection occurs between contiguous hosts. Morphological complexity brings an inherent heterogeneity in populations and affects the dynamics of pathogen spread in such systems. We have analysed the influence of realistically complex host morphology on the threshold for invasion and epidemic outbreak in an SIR (susceptible-infected-recovered) epidemiological model. We show that disorder expressed in the host morphology and anisotropy reduces the probability of epidemic outbreak and thus makes the system more resistant to epidemic outbreaks. We obtain general analytical estimates for minimally safe bounds for an invasion threshold and then illustrate their validity by considering an example of host data for branching hosts (salamander retinal ganglion cells). Several spatial arrangements of hosts with different degrees of heterogeneity have been considered in order to separately analyse the role of shape complexity and anisotropy in the host population. The estimates for invasion threshold are linked to morphological characteristics of the hosts that can be used for determining the threshold for invasion in practical applications.
在流行病学中，面临的挑战之一是当传染病在相邻宿主之间传播时，需要解释和考虑宿主（如植物根系、农田、农场、细胞、动物栖息地和社交网络）复杂的形态结构。形态复杂性给种群带来了固有异质性，并影响了病原体在这些系统中的传播动态。我们分析了真实复杂的宿主形态对 SIR（易感-感染-恢复）传染病模型中入侵和流行病爆发阈值的影响。结果表明，宿主形态中的无序和各向异性降低了流行病爆发的可能性，从而使系统更能抵抗流行病爆发。我们获得了入侵阈值最小安全边界的一般分析估计值，并通过考虑分支宿主（蝾螈视网膜神经节细胞）的宿主数据示例来说明其有效性。为了分别分析宿主种群中形状复杂性和各向异性的作用，考虑了不同异质性程度的宿主的几种空间排列。入侵阈值的估计值与宿主的形态特征相关联，这些特征可用于确定实际应用中的入侵阈值。
