Of course this rare outcome would be a risk of any operation and isn’t specific to gastric bypass:
Woman, 22, Suspected to Have One-in-a-Million Disease After Gastric Bypass Surgery
Doctors suspect a 22-year-old Virginia woman contracted the human variant of mad cow disease shortly after she had gastric bypass surgery, WAVY-TV reports.
“Tainted medical instruments and certain medical procedures” have been blamed. The patient died on April 10th three months after the operation.
Harpoon 
So, I searched for “Gastric Bypass” and this was the #1 returned result. I suppose I’ll take some comfort in the technicality that it is a risk of any post-op situation….but gee, feeling good about my surgery date coming up right about now! >_<
Woah really? That is super scary and shocking. I was searching for shocking after surgery effects. This is indeed shocking. I heard this for this one surgery, the nurse didn’t even bother to test the blood type!