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Quick Facts


(Hansen Disease; Hansen's Disease)


The Manual's Editorial Staff

Last full review/revision Oct 2020| Content last modified Oct 2020
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What is leprosy?

Leprosy is an infection caused by bacteria called Mycobacterium leprae.

  • Most cases of leprosy happen in India, Brazil, and Indonesia

  • Symptoms usually start slowly 5 to 7 years after infection

  • The disease damages mainly your nerves and skin

  • People are often afraid of leprosy because it causes visible, permanent body damage if it isn't treated

  • However, leprosy doesn’t spread easily from person to person, isn't life-threatening, and is treatable with antibiotics

What causes leprosy?

Leprosy is caused by the bacteria Mycobacterium leprae. The bacteria is spread by long-term contact with people who have leprosy. You don't get leprosy just by casually touching or passing near somebody with the disease. Also, armadillos can carry leprosy. Some people get it from contact with armadillos.

Most people who are infected don't get any symptoms because their immune system Overview of the Immune System The immune system is your body's defense system. It helps protect you from illness and infection. The immune system's job is to attack things that don’t belong in your body, including: Germs... read more fights off the infection. Leprosy symptoms develop if the immune system is weak. Some people have genes that make them more likely to get leprosy.

Most cases of leprosy happen in India, Brazil, and Indonesia. In the United States, most people with leprosy come from countries with high rates of the infection.

What are the symptoms of leprosy?

Symptoms start slowly. At first you may have:

  • Bumps and rashes on your skin—the rash doesn’t itch

  • Numbness around the rash

Later, more severe symptoms include:

How do doctors tell if I have leprosy?

Doctors will take a sample of your skin and look at it under a microscope.

How do doctors treat leprosy?

Doctors will:

  • Have you take 2 or 3 antibiotics for 6 to 24 months depending on your symptoms

Antibiotics can stop leprosy from getting worse, but they can’t cure nerve damage that's already happened. For this reason it’s important to start treatment early.

How can I prevent leprosy?

To lower your chance of getting leprosy:

  • Don’t touch the body fluids or rash on an infected person

  • Don’t touch armadillos

After people with leprosy start taking antibiotics, they can't transmit the disease. But doctors keep an eye on people in their household to see if they start having any symptoms of leprosy.

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