This town got it and now my char has it :-(
Din is useless as his later doesn't cure it.
So anyone know the answer?
If you haven't accepted a quest to do with plague, check the available quests in town. I think there should be a quest-giver (one of the main 3) who will have some info (assuming plague or some other calamity hasn't killed them, of course); regardless, I think you need to kill some plaguebringers (a type of monster) somewhere in the dungeon. This is definitely one of those quests you don't want to dawdle on, though. :)