Health officials are starting to connect the dots on how the first cow infected with mad cow disease entered the United States.
The Department of Agriculture says they believe the cow was one of 74 others imported from Canada more than 2 years ago.
They add a search is now going on to find the others and should be completed within the next several days.
The discovery of the disease has halted most exports of American beef and caused food and restaurant company stocks to tumble.
People who eat brain and spinal matter from an infected cow can develop a fatal brain disease themselves. But Dr. Ron DeHaven, of the Department of Agriculture, says dairy products are safe.
"There is no scientific evidence to suggest that milk or diary products carry the agent that causes BSE and, therefore, no scientific evidence to suggest that milk or diary products will be responsible for transmitting the disease to other animals or to people."
Mad cow disease is the unofficial name for bovine spongiform encephelopathy or BSE.
Colorado's Agriculture Commissioner says the state is ready to act if authorities determine the disease has spread.
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Mad Cow Disease
What is Mad Cow Disease?
- Mad cow, also known as bovine spongiform encephalopathy (BSE), is a disease found in cattle. Found in humans it is named Creutzfeldt-Jakob disease (VCJD).
What is Mad cow (BSE)?
- Bovine spongiform encephalopathy (BSE) is a progressive neurological disorder.
- The disease can be transmitted between cattle when infected meat is digested by the animal.
- The disease has now cure in cattle.
Transmission to Humans
- Although the risk is very small, humans can contract the disease, which is known as VCJD.
- The disease is fatal and causes brain disorders with unusually long incubation periods measured in years.
- From 1995 through June 2002, a total of 124 human cases of VCJD were reported in the United Kingdom, 6 cases in France, and 1 case each in Ireland, Italy, and the United States. The case-patients from Ireland and the United States had each lived in the United Kingdom for more than 5 years.
- Milk and milk products from cows are not believed to pose any risk for transmitting the BSE agent.
- Staying alert to U.S. government warnings during times of outbreak is very important. The U.S. government will say if avoiding beef all together is necessary.
- Selecting beef, such as solid pieces of muscle meat (versus calf brains or beef products such as burgers and sausages), which might have a reduced opportunity for contamination with tissues that may harbor the BSE agent.
Symptoms of VCJD
- The duration of CJD from the onset of symptoms to the inevitable death is usually one year; however, shorter duration periods of several months are common, and longer duration periods of two or more years have been noted.
- The initial stage of the disease can be subtle with ambiguous symptoms of:
- Personality and behavioral changes
- Strange physical sensations
- Problems with memory, coordination and sight
- As the disease advances, the patient experiences a rapidly, progressive dementia and in most cases, involuntary and irregular jerking movements known as myoclonus.
- Problems with language, sight, muscular weakness, and coordination worsen. The patient may appear startled and become rigid.
- In the final stage of the disease, the patient loses all mental and physical functions. The patient may lapse into a coma and usually dies from an infection like pneumonia precipitated by the bedridden, unconscious state.
Sources: http://www.cdc.gov/od/oc/media/fact/cjd.htm (The Center for Disease Control Web site) and http://cjdfoundation.org/CJDInfo.html (The Creutxfeldt-Jakob Disease Foundation Web site)