Patch 4.0.6 (8-Feb-2011): The spell hit bonus previously given by Virulence (Unholy) has been rolled into the Runic Focus passive effect that all death knights possess.Virulence has been redesigned. It now grants 10/20/30% additional disease damage.
/Patch 4.0.1 (12-Oct-2010): No longer reduces the chance that spells and diseases the death knight cause can be cured.
Patch 3.1.0 (14-Apr-2009): Moved from tier 2 to tier 1.