Leprosy, also known as Hansen's disease (HD), is a chronic infectious disease caused by a Mycobacterium (Mycobacterium leprae) affecting especially the skin and marginal nerves. It is characterized by the formation of nodules or macules that enlarge and spread with loss of sensation and eventually paralysis, wasting of muscle, and production of deformities called also Hansen's disease. This infection is caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. It is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract, skin lesions are the primary external sign. If left untreated, leprosy can be progressive, causing permanent damage to the skin, nerves, limbs and eyes.
Despite the elimination of leprosy as a public health problem (defined as achieving a point prevalence of below 1 per 10 000 population) globally in 2000 and at a national level in most countries by 2005, leprosy cases continue to occur. According to World Health Organisation (WHO), 216108 new leprosy cases were reported globally in 2016.
Status of leprosy in India
135485 new cases were detected during the year 2016-17 and 88166 cases were on record as on March 2017in the country (prevalence rate(PR)- 0.66 per 10000 population as on March 2017).
Out of 36 states/ UTs, 34 states and UTs achieved elimination. One State (Chhattisgarh) and one U.T. (Dadra & Nagar Haveli) are yet to achieve elimination. Five more states/UTs wherein elimination was achieved earlier, namely Odisha, Bihar, Chandigarh, Goa and Lakshadweep have reported with PR>1/10,000 population, as on 31st March 2017. Therefore, early diagnosis and treatment of leprosy is essential for reducing the burden of this disease.
National Leprosy Eradication Programme-http://nlep.nic.in/
Last updated on December 2018
The disease has following symptoms:
Mycobacterium leprae and Mycobacterium lepromatosis are the causative agents of leprosy. Mycobacterium can spread from person to person. This might happen when someone with the disease coughs or sneezes. This can release droplets into the air. It might also happen if somebody is exposed to other nasal fluids (also known as secretions) that might be contaminated with the bacteria.
Risk factors: Those living in endemic areas with poor conditions such as:
Leprosy is diagnosed by finding at least one of the following cardinal signs (WHO):
(1) definite loss of sensation in a pale (hypopigmented) or reddish skin patch;
(2) thickened or enlarged peripheral nerve, with loss of sensation and/or weakness of the muscles supplied by that nerve;
(3) presence of acid-fast bacilli in a slit-skin smear
Leprosy is classified as paucibacillary (PB) or multibacillary (MB), based on the number of skin lesions, presence of nerve involvement and identification of bacilli on slit-skin smear.
Paucibacillary (PB) case: a case of leprosy with 1 to 5 skin lesions, without demonstrated presence of bacilli in a skin smear;
Multibacillary (MB) case: a case of leprosy with more than five skin lesions; or with nerve involvement (pure neuritis, or any number of skin lesions and neuritis); or with the demonstrated presence of bacilli in a slit-skin smear, irrespective of the number of skin lesions.
The multidrug therapy (MDT) is an effective and a powerful tool in curing leprosy. Adherence to treatment and its successful completion are equally important for the cure.
The currently recommended MDT for PB leprosy is rifampicin and dapsone for 6 months and the currently recommended MDT for MB leprosy is rifampicin, clofazimine and dapsone for 12 months. MDT treatment is provided in blister packs, each containing four weeks’ treatment. Specific blister packs are available for multibacillary (MB) and paucibacillary (PB) leprosy as well for adults and children.
Recommended treatment regimens (WHO guidelines 2017*)
Multi drug therapy which consists of 3-drug regimen of rifampicin, dapsone and clofazimine for all leprosy patients, with a duration of treatment of 6 months for PB leprosy and 12 months for MB leprosy is recommended by WHO guidelines 2017*.
(For rifampicin-resistant leprosy, the guidelines recommend treatment with at least two second-line drugs (clarithromycin, minocycline or a quinolone) plus clofazimine daily for 6 months, followed by clofazimine plus one of these drugs for an additional 18 months.)
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Prevention of leprosy through chemoprophylaxis:
Use of single dose rifampicin (SDR) is recommended as preventive treatment for contacts of leprosy patients (adults and children 2 years of age and above), after excluding leprosy and TB disease, and in the absence of other contraindications. Post exposure prophylaxis with SDR for all contacts of leprosy cases has been provided under NLEP.
Prevention of leprosy through immunoprophylaxis (vaccines):
BCG vaccination at birth is effective at reducing risk of leprosy.
National Leprosy Eradication Programme:
It is centrally sponsored health programme by Ministry of Health and Family Welfare, Government of India. Elimination of Leprosy (1 case/ 10000 population at national level) was already achieved in the year 2005. The short term target is reduction of rate of Grade II disability cases (newly diagnosed leprosy patients with visible deformities) to less than one per million population, as recommended by WHO under Global Leprosy Strategy, 2016 – 2020.
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