A unit cannot heal an affliction caused by an item it still has. So no healing diseases of Fever Fetish, eyeloss caused by Eye of Aiming etc.
And I think Pangaea has some possibilities as Fever-farmer. Remember, ALL their commanders have recuperation... They don't have national mages with innate fire/nature mix, but I think that Panii can get their random in fire. I'm not sure though, as I still have to stay with the demo...
*sigh*