No one has since Rick told everyone that they all have it and will turn when they die have turned just from being bit that I can remember. However anyone that has died and not had their head lopped off or brain "killed" has been reanimated.
Herschel is the prime example.. he was bit and bit bad, thought he was going to die and asked to be killed. (if my memory serves me right) The rest of them feared IF /WHEN he died he would turn but he hadnt died yet and they tried their best to keep him alive, but tied him to the bed in case he died and turned. Herschel is still alive and was bitten.