What happened between 1980 - 1996 in the UK and Europe in general that causes the Red Cross to defer you from donating blood if you were there 3 months or more?

Answer 1

UK & Europe is listed as having a risk factor for Creutzfeldt-Jakob disease (more commonly known as mad cow disease), which is at times unscreenable, but is possible to transmit/infect other people through blood transfusion! It is a neurological disease, which causes the degeneration of brain tissues, therefore quite dangerous. For more information on this disease see the related link.

Answer 2

During this time period, there was an outbreak of variant Creutzfeldt-Jakob Disease (vCJD) in the UK, which is believed to be linked to the consumption of contaminated beef products. As a precautionary measure, the Red Cross deferred individuals who had spent a cumulative total of 3 months or more in the UK between 1980 and 1996 from donating blood, due to concerns about the risk of transmitting vCJD through blood donation.