INTRODUCTION

Leprosy, also known as Hansen’s disease (HD), is a chronic infectious disease caused by a bacteria called 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.

The disease develops slowly (from six months to 40 years) and results in skin lesions and deformities, most often affecting the cooler places on the body (for example, eyes, nose, earlobes, hands, feet, and testicles). The skin lesions and deformities can be very disfiguring and are the reason that historically people considered infected individuals outcasts in many cultures. Although human-to-human transmission is the primary source of infection, three other species can carry and (rarely) transfer M. leprae to humans: chimpanzees, mangabey monkeys, and nine-banded armadillos. The disease is termed a chronic granulomatous disease, similar to tuberculosis, because it produces inflammatory nodules (granulomas) in the skin and peripheral nerves over time. About 95% of people who contact M. Leprea do not develop the disease.

Leprosy cured person means a person who has been cured of leprosy but is suffering from:

1. loss of sensation in hands or feet as well as loss of sensation and paresis in the eye and eye-lid but with no
manifest deformity;

2. manifest deformity and paresis but having sufficient mobility in their hands and feet to enable them to engage in normal economic activity;

3. extreme physical deformity as well as advanced age which prevents him/her from undertaking any gainful occupation, and the expression “leprosy cured” shall construed accordingly.

India’s RPWD Act 2016 has recognized the leprosy cured persons with disabilities eligible for receiving disability benefits.

GRADING:

WHO Grading of Disability in Leprosy

• Grade 0
• Eyes: No eye problem due to leprosy; no evidence of visual loss
• Hands: No anaesthesia, no visible deformity or damage
• Feet: No anaesthesia, no visible deformity or damage
• Grade 1
• Eyes: Eye problem due to leprosy present, but vision not severely affected as a result of these (vision: 6/60 or better; can count fingers at 6 metres).
• Hands: Anaesthesia present, but no visible deformity or damage
• Feet: Anaesthesia present, but no visible deformity or damage
• Grade 2
• Eyes: Severe visual impairment (vision worse than 6/60, inability to count fingers at 6 metres). Also includes lagophthalmos, iridocyclitis and corneal opacities
• Hands: Visible deformity or damage present (such as cracks/wounds, claw fingers, wrist drop, contractures, amputation etc.)
• Feet: Visible deformity or damage present (such as cracks/wounds, claw toes, foot drop, contractures, amputation etc.)

EHF (Eyes, Hands, Feet) Grade Score is calculated.

Higher the Score, greater the Disability. Maximum EHF Score possible is 12.

1. EHF Score is 0-1, then % of disability is up to 20%

2. EHF Score is 2-3, then % of disability is 20% to 40%

3. EHF Score is 4-5 then % of disability is 41% to 60%

4. EHF Score is 6-7 then % of disability is 61% to 70%

5. EHF Score is 8-9 then % of disability is 71% to 80%

6. EHF Score is 10-11 then % of disability is 81% to 90%

7. EHF Score is 12 then % of disability is 91 to 100%

· Involvement of dominant upper extremity (mostly right hand), additional 10% weightage is to be given.

· Total permanent physical impairment/disability % will not exceed 100%

· Review may be done after two years, if needed or desired by the affected person, in view of likely worsening of deformities in some persons.

CLASSIFICTAION

There are multiple forms of leprosy described in the literature. The forms of leprosy depend on the person's immune response to M. leprae. A good immune response can produce the so-called tuberculoid form of the disease, with limited skin lesions and some asymmetric nerve involvement. A poor immune response can result in the lepromatous form, characterized by extensive skin and symmetric nerve involvement. Some patients may have aspects of both forms. Currently, two classification systems exist in the medical literature: the WHO system and the Ridley-Jopling system. The Ridley-Jopling system is composed of six forms or classifications, listed below according to increasing severity of symptoms:

• Indeterminate leprosy: a few hypopigmented macules; can heal spontaneously, this form persists or advances to other forms
• Tuberculoid leprosy: a few hypopigmented macules, some are large and some become anesthetic (lose pain sensation); some neural involvement in which nerves become enlarged; spontaneous resolution in a few years, persists or advances to other forms; cell-mediated immune response appears in this classification but is almost absent in lepromatous leprosy
• Borderline tuberculoid leprosy: lesions like tuberculoid leprosy but smaller and more numerous with less nerve enlargement. This form may persist, revert to tuberculoid leprosy, or advance to other forms
• Mid-borderline leprosy: many reddish plaques that are asymmetrically distributed, moderately anesthetic, with regional adenopathy (swollen lymph nodes). The form may persist, regress to another form, or progress
• Borderline lepromatous leprosy: many skin lesions with macules (flat lesions) papules (raised bumps), plaques, and nodules, sometimes with or without anesthesia; the form may persist, regress or progress to lepromatous leprosy
• Lepromatous leprosy: Early lesions are pale macules (flat areas) that are diffuse and symmetric. Later medical professionals can find many M. leprae organisms in the lesions. Alopecia (hair loss) occurs. Often patients have no eyebrows or eyelashes. As the disease progresses, nerve involvement leads to anesthetic areas and limb weakness. Progression leads to aseptic necrosis (tissue death from lack of blood to area), lepromas (skin nodules), and disfigurement of many areas, including the face. The lepromatous form does not regress to the other less severe forms. Histoid leprosy is a clinical variant of lepromatous leprosy that presents with clusters of histiocytes (a type of cell involved in the inflammatory response) and a grenz zone (an area of collagen separating the lesion from normal tissue) seen in microscopic tissue sections.

Globally, health care professionals use the Ridley-Jopling classification in evaluating patients in clinical studies. However, the WHO classification system is more widely used. It has only two forms or classifications of leprosy. The 2009 WHO classifications depend on the number of skin lesions as follows:

• Paucibacillary leprosy: skin lesions with no bacilli (M. leprae) seen in a skin smear
• Multibacillary leprosy: skin lesions with bacilli (M. leprae) seen in a skin smear

However, the WHO further modifies these two classifications with clinical criteria because "of the non-availability or non-dependability of the skin-smear services. The clinical system of classification for the purpose of treatment includes the use of number of skin lesions and nerves involved as the basis for grouping leprosy patients into multibacillary (MB) and paucibacillary (PB) leprosy." Investigators state that up to about four to five skin lesions constitutes paucibacillary leprosy, while about five or more constitutes multibacillary leprosy.

Multidrug therapy (MDT) with three antibiotics (dapsone, rifampicin, and clofazimine) treat multibacillary leprosy, while a modified MDT with two antibiotics (dapsone and rifampicin) is recommended for paucibacillary leprosy and composes most current treatments today (see treatment section below). Paucibacillary leprosy usually includes indeterminate, tuberculoid, and borderline tuberculoid leprosy from the Ridley-Jopling classification, while multibacillary leprosy usually includes the double (mid-) borderline, borderline lepromatous, and lepromatous leprosy.

TRANSMISSION

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.

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.

SIGNS AND SYMPTOMS

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:

• Discolored 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

· Nosebleeds

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

· Blindness

· Loss of eyebrows

· Nose disfigurement

Other complications that may sometimes occur are:

· Painful or tender nerves

· Redness and pain around the affected area

· Burning sensation in the skin

RISK

People at highest risk are those who live in the areas where leprosy is endemic (parts of India, China, Japan, Nepal, Egypt, and other areas) and especially those people in constant physical contact with infected people. In addition, there is some evidence that genetic defects in the immune system may cause certain people to be more likely to become infected (region q25 on chromosome 6). Additionally, people who handle certain animals known to carry the bacteria (for example, armadillos, African chimpanzee, sooty mangabey, and cynomolgus macaque) are at risk of getting the bacteria from the animals, especially if they do not wear gloves while handling the animals.

DIAGNOSIS

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.

To confirm the diagnosis, your doctor will take a sample of your 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.

TREATMENT

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 length of the treatment.

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

If you are treated for Hansen’s disease, it’s important to:

• Tell your doctor if you 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 you have numbness and loss of feeling, take extra care to prevent injuries that may occur, like burns and cuts.
• Take the antibiotics until your doctor says your treatment is complete. If you stop earlier, the bacteria may start growing again and you may get sick again.
• Tell your doctor if the affected skin patches become red and painful, nerves become painful or swollen, or you 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 be diagnosed as early as possible, before any permanent nerve damage occurs.

Leprosy is curable with multidrug therapy. Treatment of paucibacillary leprosy is with the medications dapsone, rifampicin, and clofazimine for six months. Treatment for multibacillary leprosy uses the same medications for 12 months. A number of other antibiotics may also be used. These treatments are provided free of charge by the World Health Organization. In the past 20 years, 16 million people worldwide have been cured of leprosy.