Leviticus 13:9 says if a leprous sore is on a person, then he or she must go to a priest. Verses 10-11 states the priest examines the person and if the swelling on the skin is white and has turned the hair white, and there is a spot of raw flesh in the swelling, then it's an old leprosy. The priest declares the person unclean and doesn't isolate him or her.
From reading these last two verses, it's like old school English in that a person is referred to as man for the possessive noun. It's interesting how being just unclean doesn't mean you have to be isolated from everyone, based on this verse. From reading these last verses, it appears that if the same leprosy appears again then it might not be that contagious.
Still, there would be some commotion I presume among others, and they definitely would want to avoid the person who has it. A friend told me the other night that from having an angry girl spread some gossip about him at his office, he feels like a leper among others. It's pretty funny because his reasoning is that he isn't giving her a chance for going on a date. I think it's a little more complicated than that.