MYCOBACTERIUM LEPRAE: EPIDEMIOLOGY, ETIOLOGY AND PATHOMORPHOLOGY
Abstract
Leprosy is a chronic progressive disease of man. Lepra bacilli prefer lower temperature, therefore they localize in superficial cooler tissue, i.e. skin, ears, nasal mucosa and peripheral nerves, lungs, liver, testes, eyes and bones are also affected. The incubation period is 3-15 years. Nasal discharge and skin lesion are the sources of infection. Lepra bacilli enter through damaged skin, cut, wound and nasal mucosa. The transmission of the disease is mostly by prolonged contact with infective patients. Schwann nerve cell is the target for these bacilli; thereby the nerve is damaged and ultimate manifestations of Leprosy are anesthesia and muscle paralysis. Visible lesions are due to infiltration of M. leprae into skin and cutaneous nerve. The first sign of Leprosy that heals spontaneously is a non-specific or inflammatory or indeterminate skin lesion.