... I also survived bite & scratch of a crawler (hate them ) to live almost a month with everything set up to live forever (at least it felt so). Then the game crashed while I tried to loot a house and went from 2nd floor back to 1st floor. Reloading provides me with a rollback of about a day. I went another route that day and got again bitten by another crawler - and died soon after, didn't even have the chance to eat as fast as my health drops (looks like the zombie didn't have brushed his teeth for ages then) - and yes, I bandaged the wounds and tried to recover in my safe-house. No chance. So if you ask me: if you don't evolve any pain symptoms soon after the bite/scratch, you got away this time - to die another day