Hopp Petter, Omer Mohamed K, Heier Berit T
National Veterinary Institute, PO Box 8156 Dep, NO-0033 Oslo, Norway.
J Gen Virol. 2006 Dec;87(Pt 12):3729-3736. doi: 10.1099/vir.0.81951-0.
Scrapie is a fatal, neurological disease of sheep and goats and belongs to the transmissible spongiform encephalopathies. In 1998, a new type of scrapie, designated scrapie Nor98, was detected in Norway. Scrapie Nor98 differs from classical scrapie in the distribution of pathological changes and of the scrapie prion protein, the Western blot profile of the prion protein, and with isolated cases usually being observed in the case flocks. In 2004, a case-control study was conducted on scrapie Nor98 with 28 cases and 102 randomly selected controls. The questionnaire included questions on demographic data, animal contact between sheep flocks, indirect contact with equipment, use of concentrate feed and supplemental feeds, and use of medicines and vaccines. The data were analysed by using logistic regression with the sheep flock as the statistical unit. In the final model, the detection of scrapie Nor98 was related to the practice of not removing all afterbirths, the use of vitamin and mineral feed supplements, the absence of concentrate feed of swine or poultry on the farm and the presence of dogs on the farm. The results show that the epidemiology of scrapie Nor98 differs from that of classical scrapie in that no risk factors that indicate transmission of scrapie Nor98 between flocks by movement or direct contact between animals were found. Furthermore, the association between scrapie Nor98 and mineral intake shown herein should be explored further. Although the possibility that scrapie Nor98 has a low transmissibility between animals under natural conditions cannot be ruled out, the results would also be in accordance with a spontaneous aetiology.
羊瘙痒症是绵羊和山羊的一种致命性神经疾病，属于传染性海绵状脑病。1998年，在挪威检测到一种新型羊瘙痒症，命名为Nor98型羊瘙痒症。Nor98型羊瘙痒症在病理变化分布、瘙痒病朊病毒蛋白、朊病毒蛋白的蛋白质印迹图谱方面与经典羊瘙痒症不同，并且在病例羊群中通常观察到个别病例。2004年，针对Nor98型羊瘙痒症开展了一项病例对照研究，有28个病例和102个随机选择的对照。调查问卷包括有关人口统计学数据、羊群之间动物接触、与设备的间接接触、浓缩饲料和补充饲料的使用以及药品和疫苗使用的问题。以羊群作为统计单位，采用逻辑回归分析数据。在最终模型中，Nor98型羊瘙痒症的检测与未清除所有产后胎盘的做法、维生素和矿物质饲料补充剂的使用、农场不存在猪或家禽的浓缩饲料以及农场存在狗有关。结果表明，Nor98型羊瘙痒症的流行病学与经典羊瘙痒症不同，因为未发现表明Nor98型羊瘙痒症通过动物移动或直接接触在羊群之间传播的风险因素。此外，本文所示的Nor98型羊瘙痒症与矿物质摄入之间的关联应进一步探究。尽管不能排除Nor98型羊瘙痒症在自然条件下在动物之间具有低传播性的可能性，但结果也符合自发病因。
