> Seriously, this strikes me as the stupidest thing of all time. The furor over Mad Cow Disease involved some of the most useless medical paranoia in recent memory. Meanwhile, there were no questions about possible exposure to SARS, which was, while still an overhyped threat, much more significant. Then again, SARS isn't a slow-acting virus like mad cow disease, so maybe that explains why they didn't ask about it.

As someone who has been giving blood regularly over the last eight years, I thought I could shed some light.

The UK thing is because of Mad Cow Disease. Here in Canada, they don't specify that the three months are cumulative, but they do say three months. The Canadian blood donor clinics require each donor to read a brochure explaining why they ask the things they do, partly so the donor knows how important it is to be honest. Basically, they try to cover EVERY disorder that could be transmitted by blood. There are tons of things here that can disqualify you, and I'm not sure if you just omitted a pile of them, or if your donation system is just more lenient. In any case, the Canadian blood donor system is very fast moving on new problems, and has several SARS-related questions on the screening as well as some questions relating to West Nile Virus, both of which were added shortly after the diseases became known.

My conclusion: the US blood donor screening is slow to react, and I wouldn't want to get a blood transfusion in the US. After all, I'd be 98% likely to catch SARS or WNV, if I've calculated the odds correctly.