Courteney Higgs Sally Murphy 2B October 20, 2014 Creutzfeldt-Jakob Disease Creutzfeldt-Jakob Disease, referred to as CJD, is a prion-based disease in which severe brain damaging occurs. The disease is known as a transmissible spongiform encephalopathies. Spongiform refers to the characteristic appearance of infected brains, which become filled with holes until they resemble sponges under a microscope. Prions are proteins that were not folded properly in the folding process. They replicate by converting properly folded proteins in the host to look like the same misfolded structure that they have. Which means that healthy brain tissue deteriorates into an abnormal protein that the body cannot break down.