What is the cause of leprosy?
Leprosy is an infectious disease caused by a bacillus, Mycobacterium leprae. M. leprae multiplies very slowly, and the incubation period of the disease is about five years. Symptoms can take as long as 20 years to appear. Leprosy is not highly infectious. It is transmitted via droplets from the nose and mouth during close and frequent contact with untreated multibacillary cases. What are the symptoms of leprosy? Leprosy mainly affects the skin and nerves. If untreated, there may be progressive and permanent damage to the skin, nerves, limbs and eyes. When leprosy manifests with one to five patches on the skin it is classified as paucibacillary (PB) leprosy, which is not infectious. If there are more than five patches or generalized infiltration of the skin it is classified as multibacillary (MB), which is considered infectious until treated. With minimal training, leprosy can be easily diagnosed on the basis of clinical signs alone. The PB and MB classification is for treatment purpose