Answer: Leprosy is contagious and the laws in Israel strictly regulated lepers so that they were kept away from non-lepers. Naaman was a Syrian though, so it may be that they did not have the same kind of strict rules about leprosy. Also, it says in I Kings 5:1 that Naaman had great favor with the king of Syria because he was a successful military commander, so that may have kept him from being mistreated for his leprosy.
