Travelling waves and spatial hierarchies in measles epidemics
Travelling waves and spatial hierarchies in measles epidemics
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DOI：
10.1038/414716a
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发表时间：
2001-12-13
期刊：
影响因子：
64.8
通讯作者：
Kappey, J
中科院分区：
文献类型：
--
作者：
Grenfell, BT;Bjornstad, ON;Kappey, J
时空行波是捕食者-猎物和宿主-寄生虫动力学的显著表现。然而，很少有系统被充分记录，既能探测到重复波，又能解释它们与人口结构和人口统计的时空变化的相互作用。在这里，我们展示了在详尽的时空数据集麻疹在英格兰和威尔士反复流行的行波。我们使用小波相位分析，它允许动态非平稳性-解释这些和许多其他生态时间序列的时空模式的复杂性。在预防接种时代，明显的分层感染波从大城市转移到小城镇；麻疹疫苗接种的引入限制了这种分层传染，但没有消除这种传染。一个机械随机模型提出了一种动态解释——通过传染性“火花”从大型“核心”城市传播到较小的“卫星城”。因此，宿主种群结构的空间层次是这些感染波的先决条件。
Spatio-temporal travelling waves are striking manifestations of predator-prey and host-parasite dynamics. However, few systems are well enough documented both to detect repeated waves and to explain their interaction with spatio-temporal variations in population structure and demography. Here, we demonstrate recurrent epidemic travelling waves in an exhaustive spatio-temporal data set for measles in England and Wales. We use wavelet phase analysis, which allows for dynamical nonstationarity-a complication in interpreting spatio-temporal patterns in these and many other ecological time series. In the prevaccination era, conspicuous hierarchical waves of infection moved regionally from large cities to small towns; the introduction of measles vaccination restricted but did not eliminate this hierarchical contagion. A mechanistic stochastic model suggests a dynamical explanation for the waves-spread via infective 'sparks' from large 'core' cities to smaller 'satellite' towns. Thus, the spatial hierarchy of host population structure is a prerequisite for these infection waves.