Prions cause spongiform encephalopathies which are uniformly fatal. They have a long period from exposure to manifestation of disease (1-2 years). A variant form of the prion protein PrP-27C called PrP-27Scis required for transmission. Prions are not, however, themselves immunogenic so there is no antibody development against them. This variant is B pleated rather than an alpha helical as in the normal protein. These B-sheets polymerize and form fibers in the brain.

Among the human forms of encephalopathies caused by prions are:

Kuru which is the result of cannabalism and found in the Fore tribe of New guinea.

Creutzfeldt-Jakob disease is sporadic with an unkown source. However, there was an outbreak in Great Britain in the 1980s which was traced to the fact that people ate beef from cattle who had BSE/”mad cow disease”.

Among the encephalopathies caused by prions in animals are:

BSE or “Mad Cow Disease”

Scrapie occurs naturally in sheep and is transmissible to mice. 

Transmissible mink encephalopathy