What Is Leprosy?

Causes and Risk Factors of Leprosy

M. leprae is the slow-growing bacterium behind leprosy. If a person’s immune response to the bacterium is weak — or does not occur at all — M. leprae can spread through the skin, the peripheral nerves, and, at times, into deeper tissues. Fortunately, more than 95 percent of people around the world are naturally immune to M. leprae, making leprosy a rare disease. (8) Those who are more at risk for contracting leprosy include: