Classical sheep scrapie in Great Britain: spatial analysis and identification of environmental and farm-related risk factors

Author:

Stevens Kim B,Del Río Vilas Victor J,Guitián Javier

Abstract

Abstract Background Previous studies suggest that the spatial distribution of classical sheep scrapie in Great Britain is uneven and that certain flock characteristics may be associated with occurrence of the disease. However, the existence of areas of high and low disease-risk may also result from differences in the spatial distribution of environmental characteristics. In this study we explored the spatial pattern of classical scrapie in Great Britain between 2002 and 2005 and investigated the association between disease occurrence and various environmental and farm-related risk factors. Results Exploratory spatial analysis: South Wales was found to have a higher density of scrapie-positive farms than the rest of Great Britain. In addition, a small cluster of high-risk farms was identified in the center of this region in which clustering of scrapie-positive farms occurred up to a distance of approximately 40 km. Spatial modelling: A mixed-effects regression model identified flock-size and soil drainage to be significantly associated with the occurrence of scrapie in England and Wales (area under the curve (AUC) 0.71 ± 0.01, 95% CI 0.68 - 0.74). The predictive risk map based on the estimated association between these factors and disease occurrence showed most of Wales to be at risk of being confirmed positive for scrapie with areas of highest risk in central and south Wales. In England, areas with the highest risk occurred mainly in the north and the midlands. Conclusion The observed distribution of scrapie in Great Britain exhibited a definite spatial pattern with south Wales identified as an area of high occurrence. In addition both flock (flock size) and environmental variables (soil drainage) were found to be significantly associated with the occurrence of the disease. However, the model's AUC indicated unexplained variation remaining in the model and the source of this variation may lie in farm-level characteristics rather than spatially-varying ones such as environmental factors.

Publisher

Springer Science and Business Media LLC

Subject

General Veterinary,General Medicine

Reference35 articles.

1. Stamp JT: Scrapie: a transmissible disease of sheep. The Veterinary Record. 1962, 74: 357-362.

2. Parry HB: Scrapie. London: Academic Press; 1984.

3. Anonymous: Council Directive 91/68/EEC of 28 January 1991 on animal health conditions governing intra-community trade in ovine and caprine animals. Official Journal of the European Union. 1991, L046 (19/02/1991): 19-36.

4. Green DM, Del Rio Vilas VJ, Birch CP, Johnson J, Kiss IZ, McCarthy ND, Kao RR: Demographic risk factors for classical and atypical scrapie in Great Britain. J Gen Virol. 2007, 88 (Pt 12): 3486-3492. 10.1099/vir.0.83225-0.

5. Benestad SL, Arsac J-N, Goldmann W, Nöremark M: Atypical/Nor98 scrapie: properties of the agent, genetics, and epidemiology. Vet Res. 2008, 39 (4): 19-10.1051/vetres:2007056.

Cited by 20 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3