What is leprosy?

Leprosy, also known as Hansen’s disease, is a chronic infectious disease caused by Mycobacterium leprae. The disease mainly affects the skin, the peripheral nerves, mucosal surfaces of the upper respiratory tract and the eyes. Leprosy is known to occur at all ages ranging from early infancy to very old age. Leprosy is curable and early treatment averts most disabilities.


The exact mechanism of transmission of leprosy is not known. At least until recently, the most widely held belief was that the disease was transmitted by contact between cases of leprosy and healthy persons. More recently the possibility of transmission by the respiratory route is gaining ground. There are also other possibilities such as transmission through insects which cannot be completely ruled out.

Signs/symptoms and diagnosis

Clinical signs are easy to observe. In a country or area with a high incidence of leprosy, an individual should be regarded as having leprosy if he or she shows ONE of the following cardinal signs:

  • Skin lesion consistent with leprosy and with definite sensory loss, with or without thickened nerves
  • Positive skin smears

The skin lesion can be single or multiple, usually less pigmented than the surrounding normal skin. Sometimes the lesion is reddish or copper-coloured. A variety of skin lesions may be seen but macules (flat), papules (raised), or nodules are common. Sensory loss is a typical feature of leprosy. The skin lesion may show loss of sensation to pin pick and/or light touch. Thickened nerves, mainly peripheral nerve trunks constitute another feature of leprosy. A thickened nerve is often accompanied by other signs as a result of damage to the nerve. These may be loss of sensation in the skin and weakness of muscles supplied by the affected nerve. In the absence of these signs, nerve thickening by itself, without sensory loss and/or muscle weakness is often not a reliable sign of leprosy.
Leprosy can be classified on the basis of clinical manifestations and skin smear results. In the classification based on skin smears, patients showing negative smears at all sites are said to have paucibacillary leprosy (PB), while those showing positive smears at any site are said to have multibacillary leprosy (MB).


Leprosy is curable with a combination of drugs known as multidrug therapy (MDT), as the treatment of leprosy with only one antileprosy drug (monotherapy) will result in development of drug resistance to that drug. The combination of drugs used in the MDT depends on the classification of the disease. Rifampicin, the most important antileprosy medicine, is included in the treatment of both types of leprosy. For the treatment of patients with multibacillary leprosy, WHO recommends a combination of rifampicin, clofazimine and dapsone; for patients with paucibacillary leprosy, MDT uses a combination of rifampicin and dapsone.

Multidrug therapy (MDT), first recommended by a WHO Expert Committee in 1984, rapidly became the standard treatment of leprosy and has been supplied by WHO free of charge to all endemic countries since 1995.

The Facts

  • Leprosy is curable with 6-12 months of treatment with Multidrug Therapy (MDT). The first dosage of MDT kills 99.9% of leprosy bacteria in the body.
  • Leprosy is mildly infectious if there is a prolonged exposure to untreated individual. Over 99% of people have a natural immunity or resistance to leprosy. Leprosy does not spread through touch and is also not a hereditary disease.
  • When the leprosy bacteria invade the body it causes one of two types of the disease either Paucibacillary (PB) leprosy or Multibacillary (MB) leprosy- which is more severe. In PB leprosy the body’s immune cells attempt to seal off the infection from the rest of the body. PB leprosy can cause the hair follicles, sweat glands, and nerves to be destroyed causing skin to become dry, discoloured and lose its sensation and the nerves become enlarged. MB leprosy is more contagious and severe as the body’s immune system is too weak to respond to the invading organism which multiplies freely resulting in large nodules or lesions across the body and face which can lead to severe disfigurement.
  • If diagnosed and treated at an early stage loss of sensation and disability can be prevented. As the disease progresses, patients lose sensation and strength in their fingers, toes and limbs making them susceptible to repeated burns and cuts which get infected resulting in severe ulcers. Deformities also occur on the face, hands or feet.

Social Stigma for People Affected by Leprosy

Stigma is a negative opinion or judgement held against a person or group of people who are ‘different’ from the norm. When stigma is acted upon these are acts of discrimination. Stigma and discrimination are linked. Stigmatizing thoughts can lead a person to act or behave in a way that denies services or entitlements to another person.
Even today when leprosy is curable, the age old stigma attached to it has not been cured. The stigma is a reality in the lives of the people affected with leprosy that upsets their physical, psychological, social and economical well-being.
Lack of knowledge and information, age old beliefs, fear and shame have resulted in stigma of leprosy. It results in irrational behaviour towards people affected by leprosy. People still believe that leprosy is a divine punishment for past sins and immoral behaviour. Those with leprosy are avoided as they are seen as sinful, and those around them do not want to incur God’s wrath. Since cure for leprosy was not available in the past, contracting leprosy meant life of disability and disfigurement and sure death. Behind the ostracism of those with leprosy and their family members also lies the fear of infection. Leprosy is still believed to be a hereditary disease. Even educated and respected persons can become victims of misconceptions about leprosy. The classic image of a person with disfigured body and bandages; reinforces this belief of physical uncleanliness and moral impurity, thus justifying the ostracisation and discrimination.
The stigma and discrimination extends to the family members as well. They are treated in a similar way and not allowed to function freely in the society. Therefore many families reject the person affected by leprosy for fear of exclusion thus leaving them without family, home and social support networks. As a result of stigma and discrimination people affected by leprosy often experience a loss of self esteem and dignity and feel fear, shame, hopelessness and guilt. Discrimination and lack of access to their rights and therefore have limited capacity to defend their rights and challenge stigma.