Leprosy (Hansen's Disease) Fact Sheet

Leprosy is caused by a bacterium called Mycobacterium leprae.

Leprosy is a bacterial disease of the skin and nerves, which can progress to involve internal organs if it is not treated. In some forms of leprosy, the upper airway (nose and throat) may be affected. Leprosy is more common in parts of Asia, Africa, and Latin America than it is in the United States.

The spread of leprosy requires prolonged, close contact with someone with untreated leprosy.

Leprosy is probably spread by close contact with people infected with Mycobacterium leprae. The bacteria may enter the body through the nose and broken skin. Untreated leprosy patients have millions of bacteria in the mucus from their noses.

Symptoms of leprosy include:

Skin lesions that are often painless
Nose bleeds
Nose congestion (“stuffiness")
Hair loss (eyebrows, eyelashes, body hair)

Leprosy can be treated with antibiotics.

Treatment for leprosy involves taking several antibiotics for at least 6 months and up to several years. In most cases, a person will lose the ability to infect others within days to months of starting treatment.

Leprosy can be prevented.

Early diagnosis and treatment of leprosy may prevent spread of the disease. People living in the same household as an infected person and anyone else who comes into close contact with an infected person should be examined by a doctor and continue to be examined each year for at least five years.

Leprosy is a reportable disease.

Doctors work with local health departments to evaluate people who have been in close contact with a person diagnosed with leprosy. They also work to make sure all those who need antibiotics receive them. There are no restrictions on working or attending school as long as a person is being treated correctly.