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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #314836

Title: Clinical stage of infection is critical in the antemortem diagnosis of chronic wasting disease in deer and elk

item SIEPKER, CHRIS - Kansas State University
item HALEY, NICHOLAS - Kansas State University
item WALTER, W. DAVID - Us Geological Survey (USGS)
item HOON-HANKS, LAURA - Colorado State University
item MONELLO, RYAN - Us National Park Service
item POWERS, JENNY - Us National Park Service
item Greenlee, Justin
item THOMSEN, BRUCE - Animal And Plant Health Inspection Service (APHIS)
item LEHMKUHL, AARON - Animal And Plant Health Inspection Service (APHIS)
item MITCHELL, GORDON - Canadian Food Inspection Agency
item NICHOLS, TRACY - Colorado State University
item HOOVER, EDWARD - Colorado State University
item RICHT, JUERGEN - Kansas State University

Submitted to: Prion
Publication Type: Abstract Only
Publication Acceptance Date: 3/5/2015
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Chronic wasting disease (CWD) is an efficiently transmitted spongiform encephalopathy of cervids (e.g. deer, elk, and moose), and is the only known prion disease affecting both free-ranging wildlife and captive animals. The antemortem detection of CWD and other prion diseases has proven difficult, due in part to difficulties in identifying an appropriate peripheral tissue specimen and complications with conventional test sensitivity. At present, biopsies of the recto-anal mucosal-associated lymphoid tissues (RAMALT) have shown promising sensitivity and are practical to collect in live animals. Nasal brush collections have likewise proven both sensitive and practical for identification of prion infections in humans. In this study, we evaluated both RAMALT and nasal brush collections by real time quaking-induced conversion (RT-QuIC), and compared our findings to RAMALT immunohistochemistry as well as conventional postmortem evaluation of obex and retropharyngeal lymph node tissues from over 700 captive and free-ranging deer and elk in areas with endemic CWD. We correlated our results with various clinical findings, including pathological stage of infection as determined by obex scoring, PrP genotype, age, and sex. While the sensitivity of RAMALT RT-QuIC analyses exceeded that of RAMALT IHC (69-80% vs. >44%) and nasal brush collections (15-30%), the sensitivity of both biopsy and nasal brush analyses were dependent primarily on clinical stage of disease, although PrP genotype was also an important predictor of sample positivity. Our findings further demonstrate the potential and limitations of antemortem sample analyses by RT-QuIC in the identification and management of prion diseases.