The theme of leprosy is a recurring one through the scriptures, one that graphically pictures sin and death. Most of the time those delivered from leprosy are said to be "cleansed" (rather than healed) of their leprosy.
That leprosy pictures sin is told most plainly in Numbers 12, when Miriam and Aaron had denounced Moses for marrying an African woman. Miriam is stricken with leprosy, and Aaron pleads with Moses to pray for her deliverance: "Let her not be as one dead." Miriam is in turn exiled from the camp for 7 days, but her leprosy (her sin and death) are taken away, and the people of God continue in their journey.