Well, yeah, that makes sense:

The American Red Cross is now forbidding people with CFIDS from donating blood:

http://www.washingtonpost.com/wp-dyn/content/article/2010/12/03/AR2010120305888.html

England and Canada implemented the same measure earlier this year. I've never donated blood in the 19 years I've had CFIDS, even in the early years when my doctors said I could (they've informally advised against it for awhile now), because I figured whatever was making me this ill didn't belong in the blood supply.

Glad the Red Cross is taking this step and I hope the Centers for Disease Control and NIH follow suit.