Wilesmith J W, Wells G A, Cranwell M P, Ryan J B
Epidermiology Unit, Central Veterinary Laboratory, New Haw, Weybridge, Surrey.
Vet Rec. 1988 Dec 17;123(25):638-44.
This study, initiated in June 1987, describes the epidemiology of bovine spongiform encephalopathy (BSE), a recently described novel neurological disease of domestic cattle first identified in Great Britain in November 1986. Records suggested that the earliest suspected cases occurred in April 1985. There was variability in the presenting signs and the disease course, but the majority of cases developed behavioural disorders, gait ataxia, paresis and loss of bodyweight; pruritus was not a predominant sign. The form of the epidemic was typical of an extended common source in which all affected animals were index cases. The use of therapeutic or agricultural chemicals on affected farms presented no common factors. Specific genetic analyses eliminated BSE from being exclusively determined by simple mendelian inheritance. Neither was there any evidence that it was introduced into Great Britain by imported cattle or semen. The study supports previous evidence of aetiological similarities between BSE and scrapie of sheep. The findings were consistent with exposure of cattle to a scrapie-like agent, via cattle feedstuffs containing ruminant-derived protein. It is suggested that exposure began in 1981/82 and that the majority of affected animals became infected in calfhood.
这项始于1987年6月的研究描述了牛海绵状脑病（BSE）的流行病学情况，这是一种最近发现的新型家牛神经疾病，于1986年11月在英国首次被确认。记录显示最早的疑似病例出现在1985年4月。该病的症状表现和病程存在差异，但大多数病例出现行为障碍、步态共济失调、轻瘫和体重减轻；瘙痒并非主要症状。疫情形式为典型的广泛共同来源，所有受影响动物均为指示病例。在受影响农场使用治疗性或农用化学品未发现共同因素。特定的基因分析排除了BSE完全由简单孟德尔遗传决定的可能性。也没有任何证据表明它是通过进口牛或精液传入英国的。该研究支持了之前关于BSE与绵羊瘙痒病病因相似性的证据。研究结果表明，牛通过含有反刍动物来源蛋白质的牛饲料接触到类似瘙痒病的病原体。据推测，接触始于1981/1982年，大多数受影响动物在幼年时受到感染。
