we have leper colonies in the USA???
Yes, this one on Molokai has a long history, founded by a missionary long before Hawaiian statehood. From what I've heard, there are no active cases of leprosy there right now; the residents there had active disease at one time in their lives but have been treated so that they are stable. I suppose some elect to stay there, maybe in some instances with family members.
BTW, the term leprosy seems to be politically incorrect insofar as the Hawaii Department of Health's nomenclature is concerned. It's officially designated as a Hansen's Disease facility.