It is enormously dificult to disinfect a prion!

"It is enormously dificult to disinfect a prion. What kills viruses and bacteria barely affects them. Boiling will not disinfect them, nor will heat. You can't reliably "kill" a prion with radiation. You can't pour formaldehyde on it to render it harmless-in fact formaldehyde makes prions tougher. Not all bleaches can kill prions and those that can need to be highly concentrated. Prions bond to metal. They can be spread, for instance, when doctors reuse the electrodes planted in patients' brains for EEGs or by dental equipment. To be on the safe side now, some hospitals discard the tools they use to operate on or autopsy those with CJD after a single use. Prions endure in soil too. After a flock of sheep in Iceland came down with scrapie, they were killed, and the land left unoccupied for ten years. At that point, farmers brought in a new flock, which picked up the disease. Researchers once opened up a container with the preserved brain of a person who had died of a prion disease twenty years earlier and injected the tissue into lab animals. The animals contracted the disease."