Presence of Viable Bacilli in Multibacillary Leprosy After 12 Doses of Multidrug Therapy

BACKGROUND: We investigated the clinical profiles of patients with multibacillary leprosy treated with at least 12 doses of multidrug therapy (MDT), in whom intact Mycobacterium leprae bacilli were identified in skin biopsies. METHODS: Clinical and therapeutic characteristics of 30 patients were analyzed, and their association with bacillary integrity was assessed. RESULTS: Leprosy reactions were commonly observed. Two-thirds of patients completed treatment within 5 years. A strong association was observed between the 12-dose regimen and the presence of intact bacilli. CONCLUSIONS: Clinical and laboratory aspects should be considered when deciding to discontinue MDT, particularly if leprosy reactions occur.