Prion Remains Infectious after Passage through Digestive System of American Crows (Corvus brachyrhynchos)

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 (x̄ = 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 (p̂ = 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.