KATHMANDU: Today, Nepal united with the global community to observe World Leprosy Day, marked by diverse programs held nationwide. 

The last Sunday of January is dedicated to raising awareness about leprosy, and this year’s theme, “Beat Leprosy,” emphasizes eradicating the stigma associated with the disease and promoting the dignity of those affected, as outlined by the World Health Organization.

Leprosy, caused by the bacterium Mycobacterium leprae, is a highly contagious disease. 

Dr. Rudra Prasad Marasini, Director of Epidemiology and Disease Control Division Department of Health Services, underscores the importance of timely diagnosis and treatment to effectively manage leprosy and prevent its further spread.

In the fiscal year 2079/80, Nepal identified 2,522 new leprosy patients, with the majority in the Madhes province. 

The distribution included 944 patients in Madhes, 565 in Lumbini, 471 in Koshi, 230 in Sudurpaschim, 120 in Bagmati, 119 in Gandaki, and 73 in Karnali.

Dr. Prashanna Napit, Head of the leprosy control and disability management unit, highlights the government’s commitment to a leprosy-free Nepal through the implementation of the ‘National Leprosy Strategy 2078-2082’. 

This strategy aims to comprehensively address leprosy, combining awareness, prevention, and treatment measures to eradicate the disease and promote a supportive environment for those affected.

Key facts

Leprosy is a chronic infectious disease caused by a type of bacteria, Mycobacterium leprae.

The disease predominantly affects the skin and peripheral nerves. Left untreated, the disease may cause progressive and permanent disabilities.

The bacteria are transmitted via droplets from the nose and mouth during close and frequent contact with untreated cases.

Leprosy is curable with multidrug therapy (MDT).

Leprosy is reported from all the six WHO Regions; the majority of annual new case detections are from South-East Asia.

Scope of the problem

Leprosy is a neglected tropical disease (NTD) which still occurs in more than 120 countries, with more than 200 000 new cases reported every year.

Elimination of leprosy as a public health problem globally (defined as prevalence of less than 1 per 10 000 population) was achieved in 2000 (as per World Health Assembly resolution 44.9) and in most countries by 2010.

The reduction in the number of new cases has been gradual, both globally and in the WHO regions.

As per data of 2019, Brazil, India and Indonesia reported more than 10 000 new cases, while 13 other countries (Bangladesh, Democratic Republic of the Congo, Ethiopia, Madagascar, Mozambique, Myanmar, Nepal, Nigeria, Philippines, Somalia, South Sudan, Sri Lanka and the United Republic of Tanzania) each reported 1000–10 000 new cases. Forty-five countries reported 0 cases and 99 reported fewer than 1000 new cases.

Transmission

The disease is transmitted through droplets from the nose and mouth. Prolonged, close contact over months with someone with untreated leprosy is needed to catch the disease.

The disease is not spread through casual contact with a person who has leprosy like shaking hands or hugging, sharing meals or sitting next to each other. Moreover, the patient stops transmitting the disease when they begin treatment.

Diagnosis

The diagnosis of leprosy is done clinically. Laboratory-based services may be required in cases that are difficult to diagnose. 

The disease manifests commonly through skin lesion and peripheral nerve involvement. Leprosy is diagnosed by finding at least one of the following cardinal signs:

(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) microscopic detection of bacilli in a slit-skin smear.

Based on the above, the cases are classified into two types for treatment purposes: Paucibacillary (PB) case and Multibacillary (MB) case.

PB case: a case of leprosy with 1 to 5 skin lesions, without demonstrated presence of bacilli in a skin smear.

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.

Symptoms 

Symptoms may occur within one year but can also take as long as 20 years or even more to occur.

The disease manifests commonly through skin lesion and peripheral nerve involvement. Leprosy is diagnosed by finding at least one of the following cardinal signs:

(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.

Skin lesions usually have a different pigmentation than the surrounding normal skin (less pigmented, reddish or copper-coloured) and may have various aspects (flat, raised or nodules). Skin lesions can be single or multiple with a definite loss of sensation.

Leprosy is a highly variable disease, affecting different people in different ways, according to their immune response. Those at one end of the spectrum, with a high level of immunity, harbor a low number of bacilli and are referred to as patients with PB leprosy. Those with many bacilli in the body are referred to as patients with MB leprosy.

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.

Treatment

Leprosy is a curable disease. The currently recommended treatment regimen consists of three drugs: dapsone, rifampicin and clofazimine.

The combination is referred to as multi-drug therapy (MDT). The duration of treatment is six months for PB and 12 months for MB cases. MDT kills the pathogen and cures the patient.

Early diagnosis and prompt treatment can help to prevent disabilities.

WHO has been providing MDT free of cost. Free MDT was initially funded by The Nippon Foundation and since 2000 it is being donated through an agreement with Novartis.

Prevention

Case detection and treatment with MDT alone have proven insufficient to interrupt transmission.

To boost the prevention of leprosy, with the consent of the index case, WHO recommends tracing household contacts along with neighbourhood and social contacts of each patient, accompanied by the administration of a single dose of rifampicin as preventive chemotherapy.