mad cow / scrapie / Creutzfeldt-Jakob are possibly bacterial or viral

[Guest guest]

It is still possible, Priola said, that these bad proteins are a

product of viral or bacterial infection -- possibly the real cause of

mad cow, scrapie or other transmissable spongiform encephalopathies.

[...]

" Everybody says no virus or bacteria has ever been found, but really

nobody is looking for it anymore, " Priola said. " It's difficult to get

funding for such a project. "

[...]

It's not been proven what causes any of these diseases, if it is truly

a protein or a stealthy virus. But it is clearly a disease that

involves the accumulation of bad proteins in the brain, similar to

other neurodegenerative -- but non-infectious [sic] and clinically

distinct -- diseases such as Alzheimer's or Parkinson's.

http://seattlepi.nwsource.com/national/157828_rockylab.html