BSE is spread by contact with brain or other nervous-system tissue from an infected individual. Contact can be from eating food or food by-products that have been contaminated with nervous tissue, or from instruments that have contacted diseased nervous tissue. Once the infectious agent enters the brain, it can lie dormant for several years (even as long as 10 to 15 years). When activated, the agent kills brain cells, leaving large areas of spongy holes. Also, large clumps of abnormal prion proteins (plaques) are found in brain cells. Once the agent is activated, the disease runs its course in less than one year, and ultimately results in death.
We don't know the agent that causes BSE, but we do know the following:
- The agent must be small - The agent's size must be as small or smaller than a virus.
- You can't kill it by cooking or freezing - Much higher temperatures than those used in cooking or sterilizing are required to kill it.
- Disinfectants don't work - Normal chemicals that you would use to disinfect surfaces for bacteria and viruses (Lysol, Betadine) are not effective.
- It does not appear to have genetic information (nucleic acids) - This finding has been questioned.