It is supposed to very rare, but I know 3 different people with it. 2 (husband and wife) don't eat any 4 legged meat at all, the third one takes a chance from time to time. He has been brought back from the edge 2-3 times that I know of in the back of an ambulance. The Epi pen doesn't completely bring him back; it takes paramedics. But, it doesn't affect him every time he eats 4 legged meat, so he is willing to take that chance.
**** that! Ticks are damn evil.