What is leprosy?

An infection

Bacteria are tiny microscopic organisms that can be found everywhere. Most bacteria are harmless; in fact, there are trillions of bacteria in your intestines that help you digest food.

But Mycobacterium leprae, the species that causes leprosy, is not harmless. Once infected, these bacteria affect the skin, nerves, eyes, and muscles in the hands and feet.


For Indrakhala, a 32-year old woman in Nepal, leprosy has progressed in her body. The symptoms are bad. She has numbness in her hands and feet. Because she can’t feel much pain, she could easily be cut. This could lead to an infection, which could mean losing a limb. Indrakhala’s muscles have stiffened, causing clawed hands. Her face is partially paralyzed and she can no longer blink. She could become blind.

An ancient disease

Leprosy is one of the oldest diseases known to man. In fact, M. leprae was the first bacterium known to cause disease in humans.

Today, about 95% of the population is naturally immune to leprosy, but the disease lives on because no one knows how to stop it from spreading. According to the World Health Organization, there are over 600 new cases detected every day.

ATC History

A curable disease

Leprosy may be a harsh and sad disease, but there is a cure. It’s called multi-drug therapy (MDT for short)—a blend of drugs that can wipe out all known forms of leprosy-causing bacterium. With a bit of time, usually six months to two years, a person can be cured of leprosy.

Organizations, like effect:hope ( The Leprosy Mission Canada), help to treat and care for those affected by leprosy. They also work with governments, in areas where the disease is more common, to build strong health-care systems and to provide protection for people affected by leprosy. With governments, researchers and other organizations working together, eventually, leprosy can be eliminated.