A high incidence of viableMycobacterium lepraein post-MDT recurrent lesions in tuberculoid leprosy patients

Abstract

and is used in practice particularly in tuberculoid (paucibacillary) cases presenting with freshactivity in old and/or appearance of new lesions after release from treatment. This is based onthe assumption that a delayed hypersensitivity type reaction to persisting dead bacterialproducts (antigen), causes late reversal reaction. The present study was carried out todetermine whether viable bacteria are present in recurrent lesions of tuberculoid andborderline tuberculoid leprosy cases. The type and activity of the lesions are assessedhistopathologically. The results obtained in a small group of 25 patients are presented in thispaper.Material and methodsTwenty-five skin lesional biopsies obtained from 25 cases of borderline tuberculoid (BT)leprosy referred to the Foundation between 1996 to 1998 and presenting with recurrentlesions 1–13 years after the release from treatment were studied histopathologically andalso tested for the presence of viable bacteria, using the standard mouse foot pad method.Only confirmed cases of tuberculoid leprosy with reliable treatment and follow up detailswere included in this study. For each patient, a detailed history was taken, includingpretreatment presenting symptoms, treatment details, reactions if any, followed by a clinicalcharting to record the old and the new skin lesions as well as nerve lesions. Skin smearsand lepromin testing were also done. A deep incision skin lesional biopsy was obtained froman active lesion, using local anaesthesia.