Abstract
Avian scavengers, such as American crows (Corvus brachyrhynchos), have potential to translocate infectious agents (prions) of transmissible spongiform encephalopathy (TSE) diseases including chronic wasting disease, scrapie, and bovine spongiform encephalopathy. We inoculated mice with fecal extracts obtained from 20 American crows that were force-fed material infected with RML-strain scrapie prions. These mice all evinced severe neurological dysfunction 196–231 d postinoculation ( = 198; 95% CI: 210–216) and tested positive for prion disease. Our results suggest a large proportion of crows that consume prion-positive tissue are capable of passing infectious prions in their feces ( = 1.0; 95% CI: 0.8–1.0). Therefore, this common, migratory North American scavenger could play a role in the geographic spread of TSE diseases.
Highlights
Transmissible spongiform encephalopathies (TSE) are most likely caused by pathogenic isoforms (PrPRes) of prion proteins [1] that naturally occur across many classes of animals, including mammals and birds [2]
Mule deer (Odocoileus hemionus), white-tailed deer (O. virginianus), elk (Cervus elaphus), and moose (Alces alces) are susceptible to chronic wasting disease (CWD); domestic sheep and goats are susceptible to scrapie; and domestic cattle are susceptible to bovine spongiform encephalopathy (BSE)
American crows (Corvus brachyrhynchos) are significant avian scavengers of deer carcasses [4], they are migratory, and their overall range [5] includes most areas where TSE diseases occur in North America [6]
Summary
Transmissible spongiform encephalopathies (TSE) are most likely caused by pathogenic isoforms (PrPRes) of prion proteins [1] that naturally occur across many classes of animals, including mammals and birds [2]. Mule deer (Odocoileus hemionus), white-tailed deer (O. virginianus), elk (Cervus elaphus), and moose (Alces alces) are susceptible to chronic wasting disease (CWD); domestic sheep and goats are susceptible to scrapie; and domestic cattle are susceptible to bovine spongiform encephalopathy (BSE) ( this disease is rare in North America [3]). These TSE diseases are always fatal to infected animals, and upon death, carcasses allowed to remain in the environment can be scavenged by an array of avian and mammalian scavengers [4]. Residual contamination of soil with PrPRes caused recurrence of CWD in confined mule deer in Colorado [7] and lateral transmission via environmental contamination is likely an important route of infection [9]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call