Finkenstädt B, Grenfell B
Department of Zoology, University of Cambridge, UK.
Proc Biol Sci. 1998 Feb 7;265(1392):211-20. doi: 10.1098/rspb.1998.0284.
A key issue in metapopulation dynamics is the relative impact of internal patch dynamics and coupling between patches. This problem can be addressed by analysing large spatiotemporal data sets, recording the local and global dynamics of metapopulations. In this paper, we analyse the dynamics of measles meta-populations in a large spatiotemporal case notification data set, collected during the pre-vaccination era in England and Wales. Specifically, we use generalized linear statistical models to quantify the relative importance of local influences (birth rate and population size) and regional coupling on local epidemic dynamics. Apart from the proportional effect of local population size on case totals, the models indicate patterns of local and regional dynamic influences which depend on the current state of epidemics. Birth rate and geographic coupling are not associated with the size of major epidemics. By contrast, minor epidemics--and especially the incidence of local extinction of infection--are influenced both by birth rate and geographical coupling. Birth rate at a lag of four years provides the best fit, reflecting the delayed recruitment of susceptibles to school cohorts. A hierarchical index of spatial coupling to large centres provides the best spatial model. The model also indicates that minor epidemics and extinction patterns are more strongly influenced by this regional effect than the local impact of birth rate.
集合种群动态中的一个关键问题是内部斑块动态与斑块间耦合的相对影响。这个问题可以通过分析大型时空数据集来解决，这些数据集记录了集合种群的局部和全局动态。在本文中，我们分析了英格兰和威尔士疫苗接种前时代收集的大型时空病例通报数据集中麻疹集合种群的动态。具体来说，我们使用广义线性统计模型来量化局部影响（出生率和种群规模）和区域耦合对局部疫情动态的相对重要性。除了局部种群规模对病例总数的比例效应外，模型还显示了取决于当前疫情状态的局部和区域动态影响模式。出生率和地理耦合与重大疫情的规模无关。相比之下，小规模疫情——尤其是局部感染灭绝的发生率——受到出生率和地理耦合的影响。滞后四年的出生率拟合效果最佳，反映了易感人群进入学龄队列的延迟情况。与大型中心的空间耦合分层指数提供了最佳空间模型。该模型还表明，小规模疫情和灭绝模式受这种区域效应的影响比出生率的局部影响更强。
