Model of Selective and Non-Selective Management of Badgers (Meles meles) to Control Bovine Tuberculosis in Badgers and Cattle

Bovine tuberculosis (bTB) causes substantial economic losses to cattle farmers and taxpayers in the British Isles. Disease management in cattle is complicated by the role of the European badger (Meles meles) as a host of the infection. Proactive, non-selective culling of badgers can reduce the incidence of disease in cattle but may also have negative effects in the area surrounding culls that have been associated with social perturbation of badger populations. The selective removal of infected badgers would, in principle, reduce the number culled, but the effects of selective culling on social perturbation and disease outcomes are unclear. We used an established model to simulate non-selective badger culling, non-selective badger vaccination and a selective trap and vaccinate or remove (TVR) approach to badger management in two distinct areas: South West England and Northern Ireland. TVR was simulated with and without social perturbation in effect. The lower badger density in Northern Ireland caused no qualitative change in the effect of management strategies on badgers, although the absolute number of infected badgers was lower in all cases. However, probably due to differing herd density in Northern Ireland, the simulated badger management strategies caused greater variation in subsequent cattle bTB incidence. Selective culling in the model reduced the number of badgers killed by about 83% but this only led to an overall benefit for cattle TB incidence if there was no social perturbation of badgers. We conclude that the likely benefit of selective culling will be dependent on the social responses of badgers to intervention but that other population factors including badger and cattle density had little effect on the relative benefits of selective culling compared to other methods, and that this may also be the case for disease management in other wild host populations.

牛结核病（Bovine tuberculosis，简称bTB）给不列颠群岛的养牛户与纳税人造成了巨额经济损失。由于欧洲獾（Meles meles）是该感染的宿主，牛群的疾病防控工作变得更为复杂。主动开展的非选择性獾捕杀虽可降低牛群结核病发病率，但在捕杀区域周边可能引发负面效应，这与獾种群的社会扰动现象密切相关。理论上，选择性捕杀感染个体可减少总捕杀量，但选择性捕杀对种群社会扰动及疾病转归的影响尚不明确。
我们采用已成熟的模型，针对英格兰西南部与北爱尔兰两个不同区域，分别模拟了非选择性獾捕杀、非选择性獾疫苗接种，以及选择性诱捕-接种或移除（selective trap and vaccinate or remove, TVR）的獾管理方案。在模拟TVR方案时，我们分别纳入与排除了社会扰动效应。
尽管北爱尔兰的獾种群密度更低，所有场景下感染獾的绝对数量均更少，但管理策略对獾种群的影响并未出现质的改变。不过，可能由于北爱尔兰的牛群密度存在差异，模拟的獾管理方案导致后续牛群bTB发病率出现了更大波动。
模型中的选择性捕杀使獾的致死数量减少约83%，但仅当獾种群未发生社会扰动时，该方案才能为牛结核病发病率带来整体收益。
我们得出结论：选择性捕杀的潜在收益将取决于獾对干预措施的社会响应；但相较于其他管理方案，獾与牛群密度等种群因素对选择性捕杀的相对收益影响极小，且该结论或同样适用于其他野生宿主种群的疾病防控工作。