[Edi]

Item based afflictions are dicey. I have no idea how they count.

A better test is if you put Chillsick Swamp, Crown of Darkness, Leper Fens and Inkpot end in the province where you have the old mages. Once they get disease, move them to a province next door with the priestesses and see if you can heal the affliction, because that disease is guaranteed to be normal. The test will be more reliable.