Former residents of Saudi Arabia, or Canadians who spent more than six months in Saudi Arabia during the 1980s or early ‘90s, will no longer be allowed to donate blood because of fears of mad cow disease.

Health Canada, in consultation with the Canadian Blood Services and Héma-Québec, announced the protective measure on Tuesday. The ban comes after the discovery of a "probable case" of variant Creutzfeldt-Jakob disease, which is a rare but fatal degenerative brain disease.

The patient had lived in Saudi Arabia between 1980 and 1996 and is believed to have contracted the disease while living there.

This case, along with two others, brings the total number of vCJD cases tied to current or former residents of Saudi Arabia to three.

Health Canada says Saudi Arabia imported a large amount of beef from the U.K. between 1980 and 1996, which is likely how the man picked up the disease. The man doesn't appear to have acquired it from eating beef in Canada, since he was already displaying symptoms prior to his arrival here.

Canadian Blood Services already does not accept blood donations from donors who have spent three months or more in the United Kingdom or France between 1980 and 1996. They also don't take donations from those who've spent more than five years in Western Europe outside the U.K. or France since 1980.

In addition, people are not eligible to donate blood or plasma if they received medical treatment with a product made from blood in the U.K., France or Western Europe since 1980.

Health Canada says that starting in June, a new question will be added to the information forms potential donors fill out, asking donors if they've lived in Saudi Arabia for more than three months.

"This precautionary measure will not significantly impact the supply of blood in Canada for residents needing blood transfusions," Health Canada said in a statement.

It added that there have been no reported cases of transmission of vCJD by blood transfusion in Canada and none of the three patients have ever donated blood in Canada.