Potential for American Crows to spread infectious prions in the environment

Photo courtesy María Mejía-Salazar

What role do scavengers have on the spread of prion diseases in the environment?  A recent study has shown that fecal extracts from American Crows that were fed scrapie prions were able to cause clinical disease in mice.

Prions are the causative agents of diseases such as mad cow disease, scrapie, chronic wasting disease and Creutzfeldt-Jakob disease.  This is a group of diseases known as transmissible sprongiform encephalopathies (TSE).

Other studies have suggested that scavengers may carry prions without themselves developing disease, but this is the first study to show that the prions may remain infectious when shed in feces by these animals.  This suggests that scavengers like crows may play a role in the geographic spread of TSE diseases.

For full article, please visit: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0045774