Leprosy in Hawaii; the end of an epidemic.

Two different patterns of leprosy have occurred in Hawaii. First is the continuing influx of infected people among immigrants from several leprosy-endemic areas. The number of new cases among their descendents has tended to abate within one generation after arrival in Hawaii. The most recent example of this has occurred in Asians arriving since immigration laws were liberalized in 1965, followed by a rise of imported leprosy, peaking in 1970-1980, then falling. The second pattern was an explosive epidemic among native Hawaiians, rising to its peak in the 1890s, then slowly subsiding, and now approaching zero. It appears that official disease-control efforts (physical isolation and/or early multidrug treatment) cannot fully explain the ending of the epidemic in Hawaii, in spite of the continuing importation of M. leprae. It is suggested that the influence of changing socioeconomic factors (nutrition, crowding, genetics) has been of importance, particularly among the Hawaiians, who have undergone profound foreign influence (both positive and negative) during the 150-year history of this epidemic. The late Dr. Ma Haide was responsible for leprosy control in China, where leprosy is also fading away, but not simultaneously in all subpopulations. He summarized his view by saying, "Leprosy lingers longest among the poorest" (personal communication). This statement appears to hold true for Hawaii, also.