My thought on the drunks: they aren't drunk at all. Nothing was ever really talked about with the first who turned from Ground Zero. There wasn't anything from those who lived in that area so the gas that hit them could have effected them slowly and made them seem drunk. They inhaled enough of the gas to get them started to turn and some turned faster than others, perhaps still at GZ, and those were the first who started biting others.

The guy in the holding cell was taken away from the gas so he turned slower...but still turned.