Leprosy

Leprosy is a disease caused by Mycobacterium leprae, a bacterium which primarily affects the skin and peripheral nerves. The main mode of transmission is considered to be air-borne, through droplets discharged from the respiratory tract of untreated infectious cases, who form <10% of the clinical cases. The disease is completely curable with multi-drug therapy ( MDT ) and is considered to be one of the least infectious disease, with >99% of the population having adequate immunity against the disease. However, the disease entails traditional stigma and those affected can be victims of discrimination and often displacement. This is mainly due to the disabilities and deformities that occur as a consequence of peripheral nerve damage in leprosy.  

Cause

• Leprosy is a chronic disease caused by a bacillus, Mycobacterium leprae (M. laprae).
• M.leprae multiplies very slowly and the incubation period of the disease is considered to be about five years.

Transmission

• Leprosy is transmitted by air through droplets from the nose and mouth, during close and frequent contacts with untreated cases.
• Leprosy is one of the least infectious diseases, because:
• Over 99% of the population has adequate natural immunity;
• Over 85% of the clinical cases are non-infectious, and
• An infectious case is rendered non-infectious within one week, most often after the very first dose of treatment.

Symptoms

• Leprosy mainly affects the skin and peripheral nerves.
• If left untreated, it can lead to progressive and permanent damage of nerves, leading to loss of sensation and sweating in the extremities and paralysis of muscles in the hands, feet and face.
• The disease is classified as paucibacillary(PB) or multibacillary (MB), depending on the bacillary load. PB leprosy is a milder disease characterized by few (up to five) skin lesions pale or reddish), whereas MB is associated with multiple (more than five) skin lesions, nodules, plaques, thickened dermis or skin infiltration.