ansen’s disease: how leprosy has changed

Leprosy control has improved significantly due to leprosy case detection and awareness campaigns in several endemic countries. Integration of basic leprosy services into general health services has made diagnosis and treatment of the disease more accessible.

In 2016 WHO has launched the “Global Leprosy Strategy 2016–2020: Accelerating towards a leprosy-free world” – which aims to reinvigorate efforts for leprosy control and to avoid disabilities, especially among children affected by the disease in endemic countries.

Hansen’s disease (also known as leprosy) is an infection caused by slow-growing bacteria called Mycobacterium leprae. It can affect the nerves, skin, eyes, and lining of the nose (nasal mucosa). With early diagnosis and treatment, the disease can be cured. People with Hansen’s disease can continue to work and lead an active life during and after treatment.

Leprosy was once feared as a highly contagious and devastating disease, but now we know it doesn’t spread easily and treatment is very effective. However, if left untreated, the nerve damage can result in crippling of hands and feet, paralysis, and blindness.

What is Hansen’s Disease?

Hansen’s disease (also known as leprosy) is an infection caused by bacteria called Mycobacterium leprae. These bacteria grow very slowly and it may take up to 20 years to develop signs of the infection.

The disease can affect the nerves, skin, eyes, and lining of the nose (nasal mucosa). The bacteria attack the nerves, which can become swollen under the skin. This can cause the affected areas to lose the ability to sense touch and pain, which can lead to injuries, like cuts and burns. Usually, the affected skin changes color and either becomes:

  • Lighter or darker, often dry or flaky, with loss of feeling, or
  • Reddish due to inflammation of the skin.

If left untreated, the nerve damage can result in paralysis of hands and feet. In very advanced cases, the person may have multiple injuries due to lack of sensation, and eventually, the body may reabsorb the affected digits over time, resulting in the apparent loss of toes and fingers. Corneal ulcers and blindness can also occur if facial nerves are affected. Other signs of advanced Hansen’s disease may include loss of eyebrows and saddle-nose deformity resulting from damage to the nasal septum.

Early diagnosis and treatment usually prevent disability that can result from the disease, and people with Hansen’s disease can continue to work and lead an active life. Once treatment is started, the person is no longer contagious. However, it is very important to finish the entire course of treatment as directed by the doctor. In the past, Hansen’s disease was feared as a highly contagious, devastating disease, but now we know that it’s hard to spread and it’s easily treatable once recognized. Still, a lot of stigma and prejudice remains about the disease, and those suffering from it are isolated and discriminated against in many places where the disease is seen. Continued commitment to fighting the stigma through education and improving access to treatment will lead to a world free of this completely treatable disease.

How do people get Hansen’s disease?

It is not known exactly how Hansen’s disease spreads among people. Scientists currently think it may happen when a person with Hansen’s disease coughs or sneezes, and a healthy person breathes in the droplets containing the bacteria. Prolonged, close contact with someone with untreated leprosy over many months is needed to catch the disease.

You cannot get leprosy from a casual contact with a person who has Hansen’s disease like:

  • Shaking hands or hugging
  • Sitting next to each other
    on the bus
  • Sitting together at a meal

Hansen’s disease is also not passed on from a mother to her unborn baby during pregnancy and it is also not spread through sexual contact.

Due to the slow-growing nature of the bacteria and the long time it takes to develop signs of the disease, it is often very difficult to find the source of infection.

Who Is at Risk?

In South Africa, Hansen’s disease is rare. Around the world, as many as 2 million people are permanently disabled as a result of Hansen’s disease.

Overall, the risk of getting Hansen’s disease for any adult around the world is very low. That’s because more than 95% of all people have a natural immunity to the disease.

Diagnosis and Treatment

How is the disease diagnosed?

Hansen’s disease can be recognized by the appearance of patches of skin that may look lighter or darker than the normal skin. Sometimes the affected skin areas may be reddish. Loss of feeling in these skin patches is common. You may not feel a light touch or a prick with a needle.

To confirm the diagnosis, a patients doctor will take a sample of their skin or nerve (through a skin or nerve biopsy) to look for the bacteria under the microscope and may also do tests to rule out other skin diseases.

How is the disease treated?

Hansen’s disease is treated with a combination of antibiotics. Typically, 2 or 3 antibiotics are used at the same time. These are dapsone with rifampicin, and clofazimine is added for some types of the disease. This is called multidrug therapy. This strategy helps prevent the development of antibiotic resistance by the bacteria, which may otherwise occur due to the length of the treatment.

Treatment usually lasts between one to two years. The illness can be cured if treatment is completed as prescribed.

If a person is treated for Hansen’s disease, it’s important to:

  • Tell their doctor if they experience numbness or a loss of feeling in certain parts of the body or in patches on the skin. This may be caused by nerve damage from the infection. If they have numbness and loss of feeling, they should take extra care to prevent injuries that may occur, like burns and cuts.
  • Take the antibiotics until their doctor says their treatment is complete. If they stop earlier, the bacteria may start growing again and the person may get sick again.
  • Tell their doctor if the affected skin patches become red and painful, nerves become painful or swollen, or they develop a fever as these may be complications of Hansen’s disease that may require more intensive treatment with medicines that can reduce inflammation.

If left untreated, the nerve damage can result in paralysis and crippling of hands and feet. In very advanced cases, the person may have multiple injuries due to lack of sensation, and eventually the body may reabsorb the affected digits over time, resulting in the apparent loss of toes and fingers. Corneal ulcers or blindness can also occur if facial nerves are affected, due to loss of sensation of the cornea (outside) of the eye. Other signs of advanced leprosy may include loss of eyebrows and saddle-nose deformity resulting from damage to the nasal septum.

Antibiotics used during the treatment will kill the bacteria that cause leprosy. But while the treatment can cure the disease and prevent it from getting worse, it does not reverse nerve damage or physical disfiguration that may have occurred before the diagnosis. Thus, it is very important that the disease is diagnosed as early as possible before any permanent nerve damage occurs.