You carry the Contagion and are able to spread it to others, but with significant difficulty. Only a serious disruption of your corpus (three or more corpus levels of damage) will expose others to the disease. If you fail the roll to unlock a Haunt with the Key of the Contagion, you begin Replicating.
Possible Sources: Exposure to the Contagion while Bound.
Resolution: Progress to Replicating; cure the Contagion.