Ron:
Not being blessed as a wise man I'm afraid I'm unable to answere your question with anything even remotely approaching accuracy.
The solution is very simple and very easy to apply. Feed Ruminants the food Herbivore's require. This may entail an increase in market price to the producer.
The human derivate of the disease can/and has been missdiagnosed as other more common illness for many years. More than we would like to fess up to.
I'd suggest the animal form may be present in almost all countries wether we like it or not.
I eat Beef.
50 years from now I shall not be bothered by it.
If one really takes it seriously switch to a vegetarian diet heavy on corn and beans to provide all the amino acids our bodies require for digestion. Try and stick to plants that are not fertilized. They grow slower and may have time to assimilate more essential minerals.
Egon