WASHINGTON (AP) - Some deer and elk in several Western states have been diagnosed with an illness similar to brain-destroying mad cow disease, but so far there is no evidence that people can catch the disease, the government's scientific advisers ruled Friday.
This ``chronic wasting disease'' was first identified in the 1960s, and spreads slowly through herds.
It raised concern because it is a relative of mad cow disease. People can get a similar disease called ``Creutzfeldt-Jakob disease,'' but only a new version of that illness, called ``new variant CJD,'' has been linked to eating infected beef.
The Food and Drug Administration asked experts on these brain-destroying illnesses, called ``spongiform encephalopathies,'' to gauge whether chronic wasting disease could be spread to people, either through infected meat or when hunters field-dress kills in the wild.
So far, the FDA's scientific advisers decided, the risk to people is theoretical.
``To date there's no identified instance of disease in human beings attributable to chronic wasting disease, either through contact (with sick animals) or through consumption,'' said panel chairman Dr. Paul Brown of the National Institutes of Health.
Among evidence the panel considered was microscopic and molecular biological testing of three CJD patients who were hunters. The testing diagnosed regular CJD, not the new kind linked to diet. Nor did epidemiological studies find signs of problems, Brown said.
Still, he suggested people hunting elk and deer in areas where infection occurs take caution, advising against, for example, eating the brains of such animals.
So far, chronic wasting disease has been found among deer in the wild in northeast Colorado, southeast Wyoming and parts of Nebraska. It also has been found in some commercial elk farms in Colorado, Montana, South Dakota, Nebraska and Oklahoma, and in Saskatchewan, Canada.
Sick animals lose weight, are lethargic or listless and may excessively salivate. But wildlife officials say the disease may be present up to 18 months before symptoms appear.
Most elk breeders slaughter an entire herd as a precaution when a case of chronic wasting is found, an important protective step, Brown noted.
Wildlife officials also have been tracking chronic wasting disease, asking hunters to submit the heads of kills so the brains can be tested for the illness.