Outbreak is a level 55 Unholy death knight ability that applies .
- This ability was mentioned in the April Fools' Day patch 6.1.4 Evil Patch Notes: "Outbreak no longer applies and . Instead, it applies a new, airborne version of a virus first encountered 30 years ago. Enemy players will have to work together to develop a new serum to cure the virus before the military bombs the whole city."
- Patch 7.0.3 (2016-07-19): Redesigned to an Unholy ability. Now deals Shadow damage, and causes the target and nearby enemies to be infected with .
- Patch 4.0.3a (2010-11-23): Added.