What is Mad Cow Disease?
FREDRICKA WHITFIELD, CNN ANCHOR: Well, as we've told you all morning, the U.S. Department of Agriculture has quarantined a farm near Mabton, Washington, where a cow tested positive for mad cow disease. Inspectors are tracking the meat, but it is not in the food supply, say officials. Here to talk more about this is Dr. Sandra Fryhofer. And let's begin with the basics. What is mad cow disease?</s>DR. SANDRA FRYHOFER, CNN CORRESPONDENT: Well, Fredricka, mad cow disease is a degenerative disorder that affects the neurological systems of cattle. It's called, the scientific name is Bovine Spongiform Encephalopathy, or BSE. Now, it first occurred in Britain in 1986 and was thought to be spread through contaminated cow feed. Experts think it's caused by exposure to a cell protein called a prion protein. There's also strong evidence linking mad cow with a rare form of a human disease called Variant Creutzfeldt-Jakob Disease. And in humans it causes a fatal brain disorder. It's thought to occur after eating cattle products contaminated with this prion protein. And even though there's never been a case transmitted person to person, the Red Cross will not accept blood donations from anyone who's spent at least three months in the United Kingdom or other certain European countries since 1980.</s>WHITFIELD: And even though the Department of Agriculture assures the American public that that one case, or apparent case, is not in the food supply, what would be the symptoms if, you know, mad cow disease were to, indeed, be a real threat to humans?</s>FRYHOFER: Well, Fredricka, understand that the incubation period is really long. In cattle, it's about six years. In humans it may be years to decades. And you're absolute risk of getting this is very, very small. There have been only 140 cases worldwide ever. But the symptoms in humans are, first, psychiatric symptoms, things like anxiety, depression, social withdrawal, painful sensory symptoms and then later other neurological abnormalities, including things like slurred speech, tremor, problems with walking and, finally, dementia. But, again, the incubation in human -- the incubation period in humans is absolutely years, possibly even decades.</s>WHITFIELD: All right, Dr. Sandy Fryhofer, thanks very much. We'll be talking again about this throughout the day because it is rather confusing and somewhat alarming information to hear from the U.S. Department of Agriculture.</s>FRYHOFER: Well, just stay tuned. Don't be alarmed, just stay tuned.</s>WHITFIELD: Right. All right, good advice. Thanks very much.