[Changes and present status of a Japanese National Leprosarium--analysis of smear positive rate and relapse in Hoshizuka-Keiaien between 1972-1991].

Change of clinical features of leprosy in a Japanese National Leprosarium Hoshizuka-Keiaien during 20 years (1972-91) was studied by analyzing clinical records. (1) Skin slit smear positive rate among lepromatous and borderline cases once increased from 16.3% (1972) to 28.8% (1981) and then declined to 3% (1991). (2) Relapse was 4.25 cases per annum among 817 patients (0.52% per annum). Relapse of lepromatous leprosy (0.42% per annum) is decreasing, and borderline or neuritic relapse (0.12% per annum) of previously lepromatous cases is the major feature in recent years. (3) In lepromatous relapse cases, it took 3.5 years in average to become smear negative again, but this duration is shortening in recently relapsed cases. (4) Number of erythema nodosum leprosum is remarkably decreased, but iridocyclitis is still observed. (5) 85% of inpatients in 1991 are classified as clinical cure (Japanese criteria 1989). By the advance of chemotherapy and aging of the inpatients (average age: 68 years), geriatric diseases, instead of leprosy, are becoming major problems in Japanese National Leprosaria.