: transmissible spongiform encephalopathyThe causative agent of the transmissible spongiform encephalopathies (TSE) or prion diseases, which include sheep scrapie, mad cow disease, and human variant Creutzfeldt-Jakob disease (vCJD), is still hotly debated.— Suzette A. Priola et al., Science, 9 May 2003While the methods of transmission of TSEs are not well understood … the effects of the diseases are the same whether the victim is sheep, deer, cow or human. The brain slowly erodes, with holes developing that give the organ a "spongy" appearance …— Shannon Thompkins, The Houston Chronicle, 2 June 2002
