Originally Posted by pinniped
It is. If you've lived there for longer than about 6 months, you're banned. I found this out when I tried to donate a few years ago - I lived in the UK in 1992 but was not there during any of their mad cow outbreaks. I believe they think I could still be a mad cow carrier almost 15 years later.
Since they won't take my tainted mad cow blood in the USA, I try to give blood whenever I get home to Britain, but that's not always easy during a short family visit. There certainly won't be time during my 12/23-26 trip.