I guess if you don't have in Mass. you could ask the guy where the red deer came from. If they are from disease free places, its very unlikely to get it there. New Mexico got it in the wild from secluded herds of deer because they are looking for it, I guess. I heard they think its a variant of scrapie that has been in sheep forever, but didn't pay much attention to what they said.
I was told people can't give blood in the US if they lived in Europe for so many years, during the time when mad cow was spreading there.
Its like 1/1,000,000 people that get CJD. I think we're much more likely to be hit by a car or something like that from what I've read, so far.
Red deer is very desirable meat, I think. Its common to shoot our does/hinds because of herd size limitations on food supply in a preserve.