Mad Cow Disease (BSE) and Blood Donation

Mad Cow Disease or BSE (Bovine Spongiform Encephalopathy). It's called mad cow disease because it affects a cow's nervous system, causing a cow to act strangely and lose control of its ability to do normal things, such as walk. Experts have found a link between BSE and a rare brain condition that affects people, called variant Creutzfeldt-Jakob disease (CJD). Researchers believe that people who eat beef from cows that have BSE are at risk of developing a form of CJD.
CJD is caused by an abnormal type of protein in the brain called a prion. When people have CJD, cells in the brain die until the brain eventually has a "sponge-like" appearance. During this time, people with the disease gradually lose control of their mental and physical capabilities.
By November 2006, only 200 cases of this rare condition (vCJD) had been reported worldwide. Of these, most were identified in Britain. Several of the people diagnosed with the disease outside Britain — including two cases in the United States — had a history of exposure in Britain.
As There is no test for vCJD in humans that could be used to screen blood donors and to protect the blood supply, US and many parts of the world stipulated the following are not eligible to donate blood :
Live, visited or having blood transfusion in UK during January 1, 1980 through December 31, 1996.