I don't know what it is about PF Changs, but I do know lots of people that got very sick after eating there. Including me, last September, after I ate at the one in the District near Green Valley Ranch. I was very sick to my stomach for five days. The worst case I know of was my friend's mother, who wound up in the hospital for 2 weeks....she had brought home leftovers and they tested positive so it was definitely PF Changs. The rest may be a concidence, but it just brought it to mind again after I read your report. Sorry to hear it messed up your vacation!