Like toxaplasmosis? We don't really like entertaining these things because our identities are very attatched to the idea of free will.
If you get shot, you die, even with free will. If you lose your legs, you'll be trapped in a wheelchair, even with free will. If you get infected by a zombie disease, you'll become a zombie, even with free will.
Free will simply doesn't buy you anything. You can still keep your identity without it.