Britain’s Mad Cow Disease Cited as Reason to Reject Blood Donors

ROCKVILLE, Md. — Blood banks in the United States and Canada were ordered Tuesday to stop collecting donations from people who lived in or frequently visited Britain during the mad cow disease outbreak.

The U.S. Food and Drug Administration said it took the step to prevent donors who ate tainted British beef from possibly passing along the human version of mad cow disease, a fatal degenerative brain disorder, through blood transfusions.

Canada’s health department on Tuesday ordered a similar ban.

The FDA, the agency charged with ensuring blood safety, called the move “a precautionary measure.” No case of mad cow disease or its human equivalent has ever been documented in the United States, and scientists do not even know if the disease can be transmitted through blood.

U.S. blood banks said they would adopt the policy but were worried about the impact on the nation’s blood supply, which even before the ban was projected to fall short of demand in 2000.