A parasitic infestation of the voluntary muscles, lungs, central nervous system and other organs, caused by the ingestion of eggs of the tapeworm Taenia solium.
An infectious disease caused by the bacterium Mycobacterium leprae, gradually producing nerve damage and patches of skin necrosis and historically handled by permanently quarantining its sufferers.
Similar contagious skin diseases causing light patches of scaly skin, particularly psoriasis, syphilis, vitiligo, scabies, and (biblical) the various diseases considered "tzaraath" in the Old Testament of the Bible.
Anything considered similarly permanent, harmful, and communicable, particularly when such a thing should be handled by avoidance or isolation of its victims.