Mad Cow Disease, or bovine spongiform encephalopathy (BSE), is a fatal brain disorder disease of cattle that affect the central nervous system and causes staggering and agitation. Some unknown transmissible agent causes mad Cow Disease. Currently, the most accepted theory is that the agent is a modified form of a normal cell surface component known as prion protein. In BSE, the unknown agent causes the cow 's brain cells to die, forming sponge-like holes in the brain. The cow behaves strangely and eventually dies. The connection between BSE and humans was uncovered in Great Britain in the 1990s when several young people died of a human brain disorder, a new variation of a rare brain disorder called Creutzfeldt-Jakob Disease (CJD), which typically strikes elderly people. The new variation is called new variant Creutzfeldt-Jakob Disease (nvCJD). Eating meat from cows that have been contaminated with Mad Cow Disease also exposed humans to the disease.
BSE is thought to have come from a similar disease in sheep called scrapie. In the 1980s, producers of cattle feed (which often included ground meat and bone meal by-products from sheep) changed the way they processed feed. The change somehow allowed the scrapie disease agent to survive the cattle feed production process. The contaminated food was fed to cattle, which then came down with BSE.
Neither scrapie nor BSE were thought to affect humans. Therefore, meat (nervous tissue) from BSE-infected cows made it into the food supply. Humans who ate the infected meat (probably hamburger or other processed meats) contracted the BSE-causing agent and developed nvCJD.
The agent that causes BSE is currently unknown. The following information is know about the agent:
The agent must be small - The agent 's size must be as small or smaller than a virus.
It cannot kill it by cooking or freezing - Much higher temperatures than those used in cooking or sterilizing are required to kill it.
References: How Stuff Works, Retrieved January 6, 2004 from the World Wide Web: http://science.howstuffworks.com/mad-cow-disease.htm National Center for Infectious Disease, Retrieved January 6, 2004 from the World Wide Web: http://www.cdc.gov/ncidod/diseases/cjd/bse_cjd_qa.htm Organic Consumers Association, Retrieved January 6, 2004 from the World Wide Web: http://www.organicconsumers.org/madcow/GregerBSE.cfm