Williams E S
Department of Veterinary Sciences, University of Wtoming, Laramie, USA.
Vet Pathol. 2005 Sep;42(5):530-49. doi: 10.1354/vp.42-5-530.
Chronic wasting disease (CWD) is a unique transmissible spongiform encephalopathy (TSE) of mule deer (Odocoileus hemionus), white-tailed deer (O. virginianus), and Rocky Mountain elk (Cervus elaphus nelsoni). The natural history of CWD is incompletely understood, but it differs from scrapie and bovine spongiform encephalopathy (BSE) by virtue of its occurrence in nondomestic and free-ranging species. CWD has many features in common with scrapie, including early widespread distribution of disease-associated prion protein (PrP(d)) in lymphoid tissues, with later involvement of central nervous system (CNS) and peripheral tissues. This distribution likely contributes to apparent efficiency of horizontal transmission and, in this, is similar to scrapie and differs from BSE. Clinical features and lesions of CWD are qualitatively similar to the other animal TSEs. Microscopically, marked spongiform lesions occur in the central nervous system (CNS) after a prolonged incubation period and variable course of clinical disease. During incubation, PrP(d) can be identified in tissues by antibody-based detection systems. Although CWD can be transmitted by intracerebral inoculation to cattle, sheep, and goats, ongoing studies have not demonstrated that domestic livestock are susceptible via oral exposure, the presumed natural route of exposure to TSEs. Surveillance efforts for CWD in captive and free-ranging cervids will continue in concert with similar activities for scrapie and BSE. Eradication of CWD in farmed cervids is the goal of state, federal, and industry programs, but eradication of CWD from free-ranging populations of cervids is unlikely with currently available management techniques.
慢性消耗病（CWD）是骡鹿（Odocoileus hemionus）、白尾鹿（O. virginianus）和落基山麋鹿（Cervus elaphus nelsoni）特有的一种传染性海绵状脑病（TSE）。人们对CWD的自然史了解并不完全，但由于它发生在非家养和自由放养的物种中，与羊瘙痒病和牛海绵状脑病（BSE）不同。CWD与羊瘙痒病有许多共同特征，包括疾病相关朊病毒蛋白（PrP(d)）在淋巴组织中早期广泛分布，随后累及中枢神经系统（CNS）和外周组织。这种分布可能有助于水平传播的明显效率，在这方面，它与羊瘙痒病相似，与BSE不同。CWD的临床特征和病变在性质上与其他动物TSE相似。在显微镜下，经过长时间的潜伏期和临床疾病的可变病程后，中枢神经系统（CNS）会出现明显的海绵状病变。在潜伏期，可以通过基于抗体的检测系统在组织中识别PrP(d)。虽然CWD可以通过脑内接种传播给牛、羊和山羊，但正在进行的研究尚未证明家畜通过口服接触（这是TSE假定的自然接触途径）易感。对圈养和自由放养的鹿科动物进行CWD监测的工作将与针对羊瘙痒病和BSE的类似活动协同继续。在养殖的鹿科动物中根除CWD是州、联邦和行业计划的目标，但使用目前可用的管理技术不太可能从自由放养的鹿科动物种群中根除CWD。
