I wonder how long this stuff has actually been in the wild deer and elk herds. Sometimes I think it may actually be a normal disease that has been around for centuries. Just another way mother nature controls wildlife populations.
I still think that transportation of deer heads for taxidermy across the country is a good possibility of the way this stuff is transmitted. The saw hits the brain material, some gets on the taxidermist hands, shoes or clothing and he goes out to the woods hunting and the prions etc. could/can be spread. Lots more of that happening than the actual live deer being hauled.