White P C, Lewis A J, Harris S
Environment Department, University of York, Heslington, UK.
Proc Biol Sci. 1997 Dec 22;264(1389):1737-47. doi: 10.1098/rspb.1997.0241.
A spatial stochastic simulation model was used to assess the potential of fertility control, based on a yet-to-be-developed oral bait-delivered contraceptive directed at females, for the control of bovine tuberculosis in badger populations in south-west England. The contraceptive had a lifelong effect so that females rendered sterile in any particular year remained so for the rest of their lives. The efficacy of fertility control alone repeated annually for varying periods of time was compared with a single culling operation and integrated control involving an initial single cull followed by annually repeated fertility control. With fertility control alone, in no instance was the disease eradicated completely while a viable badger population (mean group size of at least one individual) was still maintained. Near eradication of the disease (less than 1% prevalence) combined with the survival of a minimum viable badger population was only achieved under a very limited set of conditions, either with high efficiency of control (95%) over a short time period (1-3 years) or a low efficiency of control (20%) over an intermediate time period (10-20 years). Under these conditions, it took more than 20 years for the disease to decline to such low levels. A single cull of 80% efficiency succeeded in near eradication of the disease (below 1% prevalence) after a period of 6-8 years, while still maintaining a viable badger population. Integrated strategies reduced disease prevalence more rapidly and to lower levels than culling alone, although the mean badger group size following the onset of control was smaller. Under certain integrated strategies, principally where a high initial cull (80%) was followed by fertility control over a short (1-3 year) time period, the disease could be completely eradicated while a viable badger population was maintained. However, even under the most favourable conditions of integrated control, it took on average more than 12 years following the onset of control for the disease to disappear completely from the badger population. These results show that whilst fertility control would not be a successful strategy for the control of bovine tuberculosis in badgers if used alone, it could be effective if used with culling as part of an integrated strategy. This type of integrated strategy is likely to be more effective in terms of disease eradication than a strategy employing culling alone. However, the high cost of developing a suitable fertility control agent, combined with the welfare and conservation implications, are significant factors which should be taken into account when considering its possible use as a means of controlling bovine tuberculosis in badger populations in the UK.
基于一种尚未研发出来的针对雌性獾的口服诱饵避孕药，运用空间随机模拟模型来评估生育控制对英格兰西南部獾群中牛结核病的防控潜力。这种避孕药具有终身效果，即任何特定年份绝育的雌性獾在其余生都保持不育状态。将每年在不同时间段重复进行的单纯生育控制的效果，与单次捕杀行动以及包括初始单次捕杀随后每年重复生育控制的综合控制措施进行了比较。仅采用生育控制时，在仍维持一个有生存能力的獾种群（平均群体规模至少为一只个体）的情况下，疾病从未被完全根除。只有在非常有限的一组条件下，才能实现疾病的近乎根除（患病率低于1%）并维持最小生存獾种群，这些条件要么是在短时间内（1 - 3年）具有高效率的控制（95%），要么是在中等时间段（10 - 20年）具有低效率的控制（20%）。在这些条件下，疾病需要超过20年才能降至如此低的水平。一次效率为80%的捕杀行动在6 - 8年后成功使疾病近乎根除（患病率低于1%），同时仍维持一个有生存能力的獾种群。与单纯捕杀相比，综合策略能更快地降低疾病患病率并降至更低水平，尽管控制开始后獾的平均群体规模较小。在某些综合策略下，主要是在高初始捕杀率（80%）之后紧接着在短时间（1 - 3年）内进行生育控制，疾病可以在维持一个有生存能力的獾种群的同时被完全根除。然而，即使在最有利的综合控制条件下，控制开始后平均需要超过12年疾病才会从獾种群中完全消失。这些结果表明，虽然单纯使用生育控制不是控制獾群中牛结核病的成功策略，但如果与捕杀作为综合策略的一部分一起使用，它可能是有效的。这种类型的综合策略在根除疾病方面可能比单纯采用捕杀的策略更有效。然而，开发一种合适的生育控制剂的高成本，再加上福利和保护方面的影响，是在考虑将其作为控制英国獾群中牛结核病的一种手段时应予以考虑的重要因素。
