Mad cow in humans: How afraid should you be?
By Betsy Anderson
Mad cow belongs to a family of diseases called prions, which little is known about.
(CNN) -- Could that burger you're eating have a deadly secret? Or could Fido's dog food bring mad cow disease into your home?
Many questions, concerns and maybe some urban myths have been surfacing across the country since mad cow disease stampeded back into the U.S. headlines again late last month.
The announcement on December 23 that a cow infected with bovine spongiform encephalopathy, or BSE, had been discovered in Washington state mobilized the U.S. government to step up cattle screening procedures in efforts to protect the nation's beef supply.
It was the first time the disease has been found in the United States since it was first reported in Great Britain in the mid-1980s.
BSE is a transmissible, degenerative and fatal disease affecting the central nervous system of adult cattle. The disease is of concern to public health officials because it can cause variant Creutzfeldt-Jakob disease , or vCJD, a fatal brain disorder in humans.
So far, 153 people worldwide have contracted vCJD, with one case in the United States, according to the Centers for Disease Control and Prevention.
The infected tissue in animals with BSE is concentrated in the brain, spinal cord and some parts of the central nervous system. It can be spread to humans who eat these parts of the cow.
The CDC says the chance of actually contracting mad cow disease is extremely slim -- less than one in 10 billion, if at all.
But if you are concerned about your burger, the Web-based consumer advocacy group Consumeraffairs.com has come up with some precautions when you eat meat:
• Avoid brains, neck bones and beef cheeks
• Avoid bone marrow and cuts of beef that are sold on the bone
• Choose boneless cuts of meat, and for ground beef, choose only meat that is ground on-site in the store.
The group also says that unlike most other meat-borne illnesses such as E. coli bacteria, cooking does not kill mad cow disease.
But can mad cow disease be a danger to pets?
The Food and Drug Administration says that with the exception of cats, no pets are known to be able to contract mad cow disease.
Cats are susceptible to a feline version of BSE. The FDA reports that about 90 cats in the United Kingdom have contracted the disease, probably through cat food and meat scraps.
In the United States, though, safeguards put into place years ago to protect cattle have also protected cats, according to the FDA.
Some dog food also contains beef and meat by-products. In May 2003, about 1,300 bags of dog food were recalled, prompted by the possibility that the food contained parts of an infected cow in Canada.
Even though dogs cannot contract mad cow disease, the concern was that the dog food could accidentally be mixed into cattle or other animal feeds, which can then spread the disease.
Several countries have blocked imports of beef from the United States since the discovery of the infected cow, but U.S. officials say there is no reason to be alarmed and that American beef is safe.
Since the discovery of the infected cow, the USDA announced several new safeguards.
The government will no longer allow meat from "downer" animals -- cattle unable to walk without assistance -- to enter the food supply.
Also, new restrictions have been put on meat processing to make sure certain parts of the cow do not end up in the final meat product.