[Leprosy. Developmental modalities]

The very broad clinical spectrum of the Mycobacterium leprae infection is due to the diversity of the underlying immunological and genetic factors. The evolutive modalities of leprosy are mainly determined by a dual pathogenesis: An infectious disease due to a bacillus of low virulence which, even when dead, persists in the body for several years, independently of the antibiotic therapy prescribed. A dysimmune disease maintained by a chronic discharge of antigens. Neuropathies and leprous reactions are still the most troublesome episodes in the course of the disease. They constitute the principal prognostic factor in both pauci- and multibacillary forms of leprosy.