I used to donate blood here in the US all the time, but since i moved back to turkey, and when i have tried to donate here in the US they wont take it cause I've been to turkey.
The difference is, in the US (and probably in europe) people donate blood all the time, at any given time, we have blood drives, but in turkey, people arent so forthcoming to donate for no reason.
so we have a healthy supply of blood and blood products, Turkey does not, they only get it when there is a dire need and people have to enlist friends and family to donate.