Epidemiological risk assessment using linked network and grid based modelling: Phytophthora ramorum and Phytophthora kernoviae in the UK
Epidemiological risk assessment using linked network and grid based modelling: Phytophthora ramorum and Phytophthora kernoviae in the UK
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DOI：
10.1016/j.ecolmodel.2009.08.014
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发表时间：
2009-12-10
影响因子：
3.1
通讯作者：
Shaw, Michael W.
中科院分区：
文献类型：
--
作者：
Harwood, Thomas D.;Xu, Xiangming;Shaw, Michael W.
我们开发了一个随机模拟模型，将大多数过程可能是重要的疫霉ramorum和类似的疾病在英国的景观（包括杜鹃ponticum在林地和苗圃，越橘在石楠）的传播。该模拟允许在一个逼真的贸易网络和长距离的自然扩散的患病植物的运动。一系列的模拟实验运行的模型，代表一个实验不同的流行压力和自然植被和园艺贸易之间的联系，有或没有疾病传播的商业贸易，有或没有检查与根除，给一个2x2 x2 x2阶乘开始在10个任意地点遍布英格兰。在每组参数值下进行50次重复模拟。由于整个模型中的随机效应，个体流行病的规模变化很大。在一系列流行病压力下，如果将植物的商业转移包括在内，流行病的规模将扩大5-13倍。系统中一个关键的未知因素是苗圃系统外的易感栖息地面积。检查，检测的概率和受感染的植物去除效率为80%，并在90天的间隔，减少了约60%的流行病的大小在三个部门的密度为1%的易感植物在阔叶林和石南荒原。将这一密度降低到0.1%在很大程度上隔离了贸易网络，因此检查将最终的流行规模减少了90%以上，大多数流行病在没有逃逸到自然界的情况下结束了。然而，即使在这种情况下，也只有百分之几的病例发生了重大的野生流行病。如果新引进的数量仍然很低，目前的检查政策将控制大多数流行病。然而，随着引进率的增加，它可能压倒任何合理的视察制度，这主要是由于在发现之前就扩散了。(C)2009 Elsevier B. V.保留所有权利。
We developed a stochastic simulation model incorporating most processes likely to be important in the spread of Phytophthora ramorum and similar diseases across the British landscape (covering Rhododendron ponticum in woodland and nurseries, and Vaccinium myrtillus in heathland). The simulation allows for movements of diseased plants within a realistically modelled trade network and long-distance natural dispersal. A series of simulation experiments were run with the model, representing an experiment varying the epidemic pressure and linkage between natural vegetation and horticultural trade, with or without disease spread in commercial trade, and with or without inspections-with-eradication, to give a 2 x 2 x 2 x 2 factorial started at 10 arbitrary locations spread across England. Fifty replicate simulations were made at each set of parameter values. Individual epidemics varied dramatically in size due to stochastic effects throughout the model. Across a range of epidemic pressures, the size of the epidemic was 5-13 times larger when commercial movement of plants was included. A key unknown factor in the system is the area of susceptible habitat outside the nursery system. Inspections, with a probability of detection and efficiency of infected-plant removal of 80% and made at 90-day intervals, reduced the size of epidemics by about 60% across the three sectors with a density of 1% susceptible plants in broadleaf woodland and heathland. Reducing this density to 0.1% largely isolated the trade network, so that inspections reduced the final epidemic size by over 90%, and most epidemics ended without escape into nature. Even in this case, however, major wild epidemics developed in a few percent of cases. Provided the number of new introductions remains low, the current inspection policy will control most epidemics. However, as the rate of introduction increases, it can overwhelm any reasonable inspection regime, largely due to spread prior to detection. (C) 2009 Elsevier B.V. All rights reserved.