Thomsen Bruce V, Schneider David A, O'Rourke Katherine I, Gidlewski Thomas, McLane James, Allen Robert W, McIsaac Alex A, Mitchell Gordon B, Keane Delwyn P, Spraker Terry R, Balachandran Aru
National Veterinary Services Laboratories, U.S. Department of Agriculture, 1920 Dayton Avenue, Ames, IA 50010, USA.
J Vet Diagn Invest. 2012 Sep;24(5):878-87. doi: 10.1177/1040638712453582.
An effective live animal diagnostic test is needed to assist in the control of chronic wasting disease (CWD), which has spread through captive and wild herds of white-tailed deer (Odocoileus virginianus) in Canada and the United States. In the present study, the diagnostic accuracy of rectal mucosa biopsy sample testing was determined in white-tailed deer from 4 CWD-infected captive herds. Specifically, the current study compared the immunohistochemical detection of disease-associated prion protein in postmortem rectal mucosa biopsy samples to the CWD status of each deer as determined by immunodiagnostic evaluations of the brainstem at the obex, the medial retropharyngeal lymph node, and the palatine tonsil. The effects of age, sex, genotype, and disease progression were also evaluated. Diagnostic sensitivity on rectal biopsy samples for CWD in white-tailed deer ranged from 63% to 100%; the pooled estimate of sensitivity was 68% with 95% confidence limits (95% CLs) of 49% and 82%. However, diagnostic sensitivity was dependent on genotype at prion protein gene (PRNP) codon 96 and on disease progression as assessed by obex grade. Diagnostic sensitivity was 76% (95% CLs: 49%, 91%) for 96GG deer but only 42% (95% CLs: 13%, 79%) for 96GS deer. Furthermore, diagnostic sensitivity was only 36% for deer in the earliest stage of disease (obex grade 0) but was 100% for deer in the last 2 stages of preclinical disease (obex grades 3 and 4). The overall diagnostic specificity was 99.8%. Selective use of antemortem rectal biopsy sample testing would provide valuable information during disease investigations of CWD-suspect deer herds.
需要一种有效的活体动物诊断测试来协助控制慢性消耗病（CWD），该病已在加拿大和美国的圈养和野生白尾鹿（Odocoileus virginianus）群体中传播。在本研究中，对来自4个感染CWD的圈养鹿群的白尾鹿进行了直肠黏膜活检样本检测的诊断准确性测定。具体而言，本研究将死后直肠黏膜活检样本中疾病相关朊病毒蛋白的免疫组织化学检测结果与通过延髓、咽后内侧淋巴结和腭扁桃体的免疫诊断评估确定的每只鹿的CWD状态进行了比较。还评估了年龄、性别、基因型和疾病进展的影响。白尾鹿CWD直肠活检样本的诊断敏感性范围为63%至100%；敏感性的合并估计值为68%，95%置信区间（95%CLs）为49%至82%。然而，诊断敏感性取决于朊病毒蛋白基因（PRNP）密码子96处的基因型以及通过延髓分级评估的疾病进展。96GG基因型的鹿诊断敏感性为76%（95%CLs：49%，91%），但96GS基因型的鹿仅为42%（95%CLs：13%，79%）。此外，疾病最早阶段（延髓分级0）的鹿诊断敏感性仅为36%，但临床前疾病最后两个阶段（延髓分级3和4）的鹿诊断敏感性为100%。总体诊断特异性为99.8%。在对疑似感染CWD的鹿群进行疾病调查期间，选择性地使用生前直肠活检样本检测将提供有价值的信息。
