Leprosy also known as Hansen's disease is an infection caused by slow-growing 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 has been around since ancient times.
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.
Each year, about 250,000 people around the world get the illness. In the past, 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. Children are more likely to get leprosy than adults.
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 Leprosy?
It is not known exactly how Hansen's disease spreads between 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.
People are generally no longer infectious after the first month of standard multi-drug therapy.
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 in a bus
Sitting together at a meal
Leprosy 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?
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 natural immunity to the disease.
You may be at risk for the disease if you live in a country where the disease is widespread. Countries that reported more than 1,000 new cases of Hansen’s disease to WHO between 2011 and 2015 are:
Africa: Democratic Republic of Congo, Ethiopia, Madagascar, Mozambique, Nigeria, United Republic of Tanzania
Asia: Bangladesh, India, Indonesia, Myanmar, Nepal, , Philippines, Sri Lanka
Geographical Distribution of New Cases of Hansen’s Disease Reported to WHO in 2015
India reported 127,326 new cases, accounting for 60% of the global new leprosy cases; Brazil, reported 26,395 new cases, representing 13% of the global new cases; and Indonesia reported 17,202 new cases, 8% of the global case load. No other countries reported greater than 10,000 new cases. Eleven countries reported between 1,000 and 10,000 cases: from Africa, the Democratic Republic of Congo, Ethiopia, Madagascar, Mozambique, Nigeria and United Republic of Tanzania; from Southeast Asia, Bangladesh, Myanmar, Nepal and Sri Lanka; and from Western Pacific, the Philippines. Collectively, these countries reported 19,069 new cases, 14% of all new cases globally. The remaining 10,286 new cases (5%) were reported by 92 countries. Thirty countries reported zero new cases. Ninety-two countries did not report, several of which are known to have cases of leprosy.
You may also be at risk if you are in prolonged close contact with people who have untreated Hansen’s disease. If they have not been treated, you could get the bacteria that cause Hansen’s disease. However, as soon as patients start treatment, they are no longer able to spread the disease.
Symptoms of Leprosy
Symptoms mainly affect the skin, nerves, and mucous membranes (the soft, moist areas just inside the body's openings).
The disease can cause skin symptoms such as:
Discoloured patches of skin, usually flat, that may be numb and look faded (lighter than the skin around)
Growths (nodules) on the skin
Thick, stiff or dry skin
Painless ulcers on the soles of feet
Painless swelling or lumps on the face or earlobes
Loss of eyebrows or eyelashes
Symptoms caused by damage to the nerves are:
Numbness of affected areas of the skin
Muscle weakness or paralysis (especially in the hands and feet)
Enlarged nerves (especially those around the elbow and knee and in the sides of the neck)
Eye problems that may lead to blindness (when facial nerves are affected)
Symptoms caused by the disease in the mucous membranes are:
A stuffy nose
Since Hansen’s disease affects the nerves, loss of feeling or sensation can occur. When loss of sensation occurs, injuries such as burns may go unnoticed. Because you may not feel the pain that can warn you of harm to your body, take extra caution to ensure the affected parts of your body are not injured.
If left untreated, the signs of advanced leprosy can include:
Paralysis and crippling of hands and feet
Shortening of toes and fingers due to reabsorption
Chronic non-healing ulcers on the bottoms of the feet
Loss of eyebrows
Other complications that may sometimes occur are:
Painful or tender nerves
Redness and pain around the affected area
Burning sensation in the skin
How is Leprosy Diagnosed?
Hansen's disease can be recognized by 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.
If you have a suspicious skin sore, your doctor will remove a small sample of the abnormal skin and send it to a lab to be examined. This is called a skin biopsy. A skin smear test may also be done. With paucibacillary leprosy, no bacteria will be detected. In contrast, bacteria are expected to be found on a skin smear test from a person with multibacillary leprosy.
Can Leprosy be Treated?
Leprosy can be cured. In the last two decades, 16 million people with leprosy have been cured. The World Health Organization provides free treatment for all people with leprosy.
Treatment depends on the type of leprosy that you have. Antibiotics are used to treat the infection. Long-term treatment with two or more antibiotics is recommended, usually from six months to a year. People with severe leprosy may need to take antibiotics longer. Antibiotics cannot treat the nerve damage.
Anti-inflammatory drugs are used to control nerve pain and damage related to leprosy. This may include steroids, such as prednisone.
Patients with leprosy may also be given thalidomide, a potent medication that suppresses the body's immune system. It helps treat leprosy skin nodules. Thalidomide is known to cause severe, life-threatening birth defects and should never be taken by women who are pregnant or women who may become pregnant.
Thus, it is very important that the disease be diagnosed as early as possible, before any permanent nerve damage occurs.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 dis-figuration that may have occurred before the diagnosis.
How Can I Prevent Leprosy?
The best way to prevent leprosy is to avoid long-term, close contact with an untreated, infected person.
Despite effective treatment and education efforts, leprosy stigma continues to be problematic in endemic developing countries. Leprosy is most prevalent amongst impoverished or marginalized populations where social stigma is likely to be compounded by other social inequities. Fears of ostracism, loss of employment, or expulsion from family and society may contribute to a delayed diagnosis and treatment.
Folk models of belief, lack of education, and religious connotations of the disease continue to influence social perceptions of those afflicted in many parts of the world. In Brazil, for example, folklore holds that leprosy is transmitted by dogs, it is a disease associated with sexual promiscuity, and is sometimes thought to be punishment for sins or moral transgressions. Socioeconomic factors also have a direct impact. Lower-class domestic workers who are often employed by those in a higher socioeconomic class may find their employment in jeopardy as physical manifestations of the disease become apparent. Skin discoloration and darker pigmentation resulting from the disease also have social repercussions.
In extreme cases in northern India, leprosy is equated with an "untouchable" status that "often persists long after (individuals with leprosy) have been cured of the disease, creating lifelong prospects of divorce, eviction, loss of employment, and ostracism from family and social networks."
In order to reinvigorate efforts for leprosy control WHO has developed the"“Global Leprosy Strategy 2016‒2020", which is structured around the following 3 core pillars:
Pillar I: Strengthen government ownership, coordination and partnership
Key activities of Pillar I include:
Ensuring political commitment and adequate resources for leprosy programmes.
Contributing to universal health coverage with a special focus on children, women and underserved populations including migrants and displaced people.
Promoting partnerships with state and non-state actors and promoting intersectoral collaboration and partnerships at the international and national levels.
Facilitating and conducting basic and operational research in all aspects of leprosy and maximizing the evidence base to inform policies, strategies and activities.
Strengthening surveillance and health information systems for programme monitoring and evaluation (including geographical information systems).
Pillar II: Stop leprosy and its complications
Key activities of Pillar II include:
Strengthening patient and community awareness of leprosy.
Promoting early case detection through active case-finding (such as campaigns) in areas of higher endemicity and contact management.
Ensuring prompt start of, and adherence to treatment, including working towards improved treatment regimens.
Improving prevention and management of disabilities.
Strengthening surveillance for antimicrobial resistance including laboratory network.
Promoting innovative approaches for training, referrals, and sustaining expertise in leprosy, such as e-health.
Promoting interventions for the prevention of infection and disease.
Pillar III: Stop discrimination and promote inclusion
Key activities of Pillar III include:
Promoting societal inclusion by addressing all forms of discrimination and stigma.
Empowering persons affected by leprosy and strengthening their capacity to participate actively in leprosy services.
Involving communities in action for improvement of leprosy services.
Promoting coalition-building among persons affected by leprosy and encouraging the integration of these coalitions and/or their members with other community-based organizations.
Promoting access to social and financial support services, for example to facilitate income generation, for persons affected by leprosy and their families.
Supporting community-based rehabilitation for people with leprosy-related disabilities.
Working towards abolishing discriminatory laws and promoting policies facilitating inclusion of persons affected by leprosy.
Targets of the strategy
The targets of the new global strategy to be met by 2020 are:
Zero disabilities among new paediatric patients.
A grade-2 disability rate of less than 1 case per 1 million people.
Zero countries with legislation allowing discrimination on basis of leprosy.
Sustained and committed efforts by the national programmes along with continued support from national and international partners have led to a decline in the global burden of leprosy. Increased empowerment of people affected by the disease, together with their greater involvement in services and the community, will bring us closer to a world without leprosy.
In August 2016, WHO published an Operational Manual to facilitate adaptation and implementation of the Global Leprosy Strategy 2016‒2020. The purpose of this manual is to provide guidance for managers of national leprosy programmes (or equivalent entities) to adapt and implement the Global Leprosy Strategy according to the epidemiological burden of their own country.