From WoWWiki
Overview
Disease is a
Dispel Type that can be inflicted by some bosses and mobs. They do only exist as
Debuffs, not as
Buffs. Disease debuffs tend to inflict various negative effects to
attributes as well as
Damage over time, and tend to be long-lasting effects (normally between 5 and 30 minutes). Mobs that cause disease are usually only those with some indicating word in their name, like "diseased", "rabid" or "tainted". Many
Undead creatures cause disease.
Additional note: Apart from the Undead Priest's racial Devouring Plague, there is currently no player ability in the game that causes a disease. In Wrath of the Lich King, however, some Death Knight abilities will include disease effects.
See Category:Disease Debuffs
List of Disease Removing Abilities
Diseases are curable by many methods:
Paladin
Priest
Shaman
Dwarf
Item
