Disease casted by Diseased Kobolds in the Warrens.
 

I'm not sure on the duration of this debuff, but I've been online with it fighting mobs that don't refresh that particular debuff for about seven hours now.

No clue on if this is meant to be permanent and needs to be removed via cure disease, or if it's bugged. Just figured I'd mention it since I've never seen a debuff last this long.

I have this, have had it for weeks. Haven't found any mention of a permanent version of Disease, but it sure seems to be...