Velthuis A G J, Mourits M C M
Business Economics, Wageningen University, Hollandseweg 1, 6706 KN Wageningen, The Netherlands.
Prev Vet Med. 2007 Dec 14;82(3-4):262-81. doi: 10.1016/j.prevetmed.2007.05.023. Epub 2007 Jul 12.
After the foot-and-mouth disease (FMD) outbreak in 2001 the Dutch government implemented movement-prevention regulations to reduce the number of contacts between farms and consequently the risk of spread of highly contagious animal infections in the future. We studied the efficacy of these regulations by comparing registered cattle-movement data from 2000 to those from 2002. We also used the spatial and stochastic simulation model InterFMD to evaluate the consequences of the observed alterations in cattle-contact structure on the spread and control of a FMD epidemic. There was a significant decrease in the number of cattle movements "for live use", no difference in the number of group movements "for live use" and a distinct change in the overall contact structure. The most important structure changes were a decrease in the number of group movements from dairy farms to cattle-collection centres (-44%), and an increase in the number of group movements from dairy farms to beef farms (111%). Our simulations demonstrated that the implemented regulations result in a concentration of the FMD-affected area and therefore in a reduction in size of the epidemics. Based on the intended Dutch strategy to control future FMD outbreaks, the decrease in extreme epidemics (95th percentiles) went from 31 infected farms in an epidemic-length of 65 days to 8 infected farms in an epidemic-length of 53 days in sparsely populated areas. In densely populated areas this decrease went from 135 infected farms to 103, while the duration reduced from 88 days to 81.
2001年口蹄疫爆发后,荷兰政府实施了移动预防规定,以减少农场之间的接触次数,从而降低未来高传染性动物感染传播的风险。我们通过比较2000年和2002年的注册牛移动数据,研究了这些规定的效果。我们还使用空间和随机模拟模型InterFMD来评估观察到的牛接触结构变化对口蹄疫疫情传播和控制的影响。“用于活体用途”的牛移动次数显著减少,“用于活体用途”的群体移动次数没有差异,整体接触结构发生了明显变化。最重要的结构变化是从奶牛场到牛收集中心的群体移动次数减少(-44%),以及从奶牛场到肉牛场的群体移动次数增加(111%)。我们的模拟表明,实施的规定导致口蹄疫感染区域集中,从而使疫情规模减小。根据荷兰控制未来口蹄疫爆发的既定策略,在人口稀少地区,极端疫情(第95百分位数)的减少从疫情持续65天时有31个感染农场降至疫情持续53天时有8个感染农场。在人口密集地区,这一减少从135个感染农场降至103个,而持续时间从88天降至81天。