Marsh R F, Bessen R A
Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison 53706.
Dev Biol Stand. 1993;80:111-8.
Transmissible mink encephalopathy (TME) is a rare foodborne disease of ranch-raised mink produced by an as yet unidentified contaminated feed ingredient. Because of the clinicopathologic similarities to scrapie and the indistinguishable physicochemical properties of their transmissible agents, it was initially assumed that TME was caused by feeding mink scrapie-infected sheep. However, subsequent studies testing the oral susceptibility of mink to scrapie were unsuccessful. Epidemiologic investigations of individual incidents of TME have not identified an association between the occurrence of disease and the feeding of any particular ingredient. However, there are two incidents in which the rancher was confident that sheep were not fed. The most recent of these was in Stetsonville, Wisconsin in 1985 where the meat portion of the diet was composed almost exclusively of downer dairy cows. To examine the possibility that cattle may have been the source of infection on the Stetsonville ranch, mink brain was experimentally inoculated intracerebrally into two Holstein steers. Both of these animals developed fatal spongiform encephalopathies 18 and 19 months after inoculation. These findings are compatible with the Stetsonville incident of TME being caused by feeding mink infected cattle tissue and they suggest the presence of an unrecognized BSE-like disease in the United States. Further experimental studies on the Stetsonville source of TME have identified two distinct strains of the transmissible agent in Syrian hamsters. These strains vary in length of incubation period, clinical signs, endstage brain infectivity titre, and pathogenicity for mink.(ABSTRACT TRUNCATED AT 250 WORDS)
传染性水貂脑病（TME）是一种罕见的食源性疾病，发生在牧场饲养的水貂身上，由一种尚未确定的受污染饲料成分引起。由于其临床病理学与羊瘙痒症相似，且其传播因子的物理化学性质无法区分，最初人们认为TME是由于给水貂喂食感染了羊瘙痒症的绵羊所致。然而，随后测试水貂对羊瘙痒症口服易感性的研究并未成功。对TME个别事件的流行病学调查并未发现疾病发生与任何特定成分的喂食之间存在关联。然而，有两起事件中牧场主确信没有喂过羊。其中最近的一起发生在1985年威斯康星州的斯特森维尔，当时日粮的肉类部分几乎完全由淘汰奶牛组成。为了研究牛可能是斯特森维尔牧场感染源的可能性，将水貂脑通过脑内接种的方式接种到两头荷斯坦公牛体内。这两头动物在接种后18个月和19个月都患上了致命的海绵状脑病。这些发现与斯特森维尔的TME事件是由给水貂喂食受感染的牛组织引起的这一观点相符，并且表明美国存在一种未被识别的类似疯牛病的疾病。对斯特森维尔TME来源的进一步实验研究在叙利亚仓鼠中鉴定出了两种不同的传播因子菌株。这些菌株在潜伏期长度、临床症状、终末期脑感染滴度以及对水貂的致病性方面存在差异。（摘要截取自250字）
