Kuru victims usually remained mentally aware for several years, while losing their abilities at coordination. Prion diseases apparantly run throughout the animal world. Sheep scrapie, mink encephalopathy, and elk diseases are examples. Pigs and chickens do not appear to get prion diseases because they are usually sent to market before such diseases would appear. However, there is some experimental evidence that they can be, and sometimes actually may be infected.
Prion diseases can jump species.
The infection is through the food chain, rather than by contact. There is no way of absolutely preventing infection. Prions keep their shape even if boiled, steamed, hammered, and autoclaved for hours. They may cling to sterile instruments previously used in brain surgery or may be transmitted by corneal transplants. The issue is not so far removed from genetics.