Bacteriological status (point prevalence) of lepromatous outpatients under sulfone treatment.

The study concerns 337 outpatients with lepromatous leprosy who had been receiving dapsone treatment for 1-26 years-69% of them regularly and 31% irregularly. Routine bacterial examination (10 min per slide) by a paramedical technician showed only 50% of these patients to be bacteriologically positive. This rate attained 99% when each slide was examined for 30-60 min by a qualified bacteriologist. Other factors-apart from the limited action of sulfones-might account for these unexpected results: the material was collected by an experienced leprologist; the disease was still clinically active in 75% of the patients; about 25% of them had been treated for only 1-4 years; and the intake of dapsone in long-term treatment gradually decreases.