Hate to tell you this, but it's not just Taco Bell at fault. You live in Memphis now, and ANY fast food resturant here has about 10% chance of serving you up some rancid, undercooked, and probably non refrigerated crap. My bro works for US food services he tells me all the places to avoid. As a result I have almost stoped going to all fast food resturants to keep myself healthy. I do on occasion get the urge but often regret it shortly after.
BTW chicken is the worst risk for food poisoning. Drink lots of liquids you don't want to get dehydrated.