Lucey B T, Russell C A, Smith D, Wilson M L, Long A, Waller L A, Childs J E, Real L A
Department of Biology, Rollins School of Public Health, Emory University, Atlanta, Georgia 30345, USA.
Vector Borne Zoonotic Dis. 2002 Summer;2(2):77-86. doi: 10.1089/153036602321131878.
The quantitative analysis of pathogen transmission within its specific spatial context should improve our ability to predict and control the epizootic spread of that disease. We compared two methods for calibrating the effect of local, spatially distributed environmental heterogeneities on disease spread. Using the time-of-first-appearance of raccoon rabies across the 169 townships in Connecticut, we estimated local spatial variation in township-to-township transmission rate using Trend Surface Analysis (TSA) and then compared these estimates with those based on an earlier probabilistic simulation using the same data. Both the probabilistic simulation and the TSA reveal significant reduction in transmission when local spatial domains are separated by rivers. The probabilistic simulation suggested that township-to-township transmission was reduced sevenfold for townships separated by a river. The global effect of this sevenfold reduction is to increase the time-to-first-appearance in the eastern townships of Connecticut by approximately 29.7% (spread was from west to east). TSA revealed a similar effect of rivers with an overall reduction in rate of local propagation due to rivers of approximately 22%. The 7.7% difference in these two estimates reveals slightly different aspects of the spatial dynamics of this epizootic. Together, these two methods can be used to construct an overall picture of the combined effects of local spatial variation in township-to-township transmission on patterns of local rate of propagation at scales larger than the immediate nearest neighboring townships.
在特定空间背景下对病原体传播进行定量分析，应能提高我们预测和控制该疾病 epizootic 传播的能力。我们比较了两种校准局部空间分布环境异质性对疾病传播影响的方法。利用浣熊狂犬病在康涅狄格州 169 个乡镇首次出现的时间，我们使用趋势面分析（TSA）估计了乡镇间传播率的局部空间变化，然后将这些估计值与基于相同数据的早期概率模拟结果进行比较。概率模拟和 TSA 均显示，当局部空间区域被河流分隔时，传播显著减少。概率模拟表明，被河流分隔的乡镇间传播减少了七倍。这种七倍减少的总体效果是使康涅狄格州东部乡镇的首次出现时间增加约 29.7%（传播方向是从西向东）。TSA 揭示了河流的类似影响，由于河流，局部传播速率总体降低了约 22%。这两个估计值 7.7% 的差异揭示了这种 epizootic 空间动态的略有不同的方面。这两种方法一起可用于构建一幅总体图景，展示乡镇间传播的局部空间变化对大于紧邻乡镇尺度的局部传播速率模式的综合影响。
