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Leprosy

Fact sheet
Updated October 2017


Key facts

  • Leprosy is a chronic disease caused by a bacillus, Mycobacterium leprae.
  • M. leprae multiplies slowly and the incubation period of the disease, on average, is 5 years. In some cases, symptoms may occur within 1 year but can also take as long as 20 years to occur.
  • The disease mainly affects the skin, the peripheral nerves, mucosa of the upper respiratory tract, and also the eyes.
  • Leprosy is curable with multidrug therapy (MDT).
  • Leprosy is transmitted via droplets, from the nose and mouth, during close and frequent contacts with untreated cases.
  • Untreated, leprosy can cause progressive and permanent damage to the skin, nerves, limbs, and eyes.
  • Official figures from 145 countries from 6 WHO regions show the global registered leprosy cases at 216 108.
  • Based on 173 358 cases at the end of 2016, case detection rate corresponds to 2.9/100.0.

Introduction

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, an acid-fast, rod-shaped bacillus. The disease mainly affects the skin, the peripheral nerves, mucosa of the upper respiratory tract, and the eyes. Leprosy is curable and treatment in the early stages can prevent disability.

Brief history of the disease and treatment

Leprosy is an age-old disease, described in the literature of ancient civilizations. Throughout history, people afflicted have often been ostracized by their communities and families.

Although leprosy was managed differently in the past, the first breakthrough occurred in the 1940s with the development of the medicine dapsone. The duration of treatment lasted many years, often a lifetime, making compliance difficult. In the 1960s, M. leprae started to develop resistance to dapsone, the world’s only known anti-leprosy medicine at that time. In the early 1960s, rifampicin and Clofazimine were discovered and subsequently added to the treatment regimen, which was later labelled as multidrug therapy (MDT).

In 1981, a WHO Study Group recommended MDT. MDT consists of 2 or 3 medicines: dapsone and rifampicin for all patients, with Clofazimine added for multi-bacillary disease. This latter combination kills the pathogen and cures the patient.

Since 1995 WHO has provided MDT free of cost to all leprosy patients in the world. Free MDT was initially funded by The Nippon Foundation, and since 2000 it is donated through an agreement with Novartis which recently committed to extend its donation to 2020.

Elimination of leprosy as public health problem (defined as a registered prevalence of less than 1 case per 10 000 population) was achieved globally in 2000. More than 16 million leprosy patients have been treated with MDT over the past 20 years.

WHO response

In 2016 WHO launched its "Global Leprosy Strategy 2016–2020: Accelerating towards a leprosy-free world" to reinvigorate efforts for leprosy control. The strategy focuses on avoiding disabilities, especially among children.

The Global Leprosy Strategy 2016‒2020 is structured around following 3 core pillars:

Pillar I: Strengthen government ownership, coordination and partnership

Key interventions

  • 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 interventions

  • 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 interventions

  • 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 Global Leprosy Strategy
  • 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.

In August 2016, WHO published an Operational Manual to facilitate adaptation and implementation of the Global Leprosy Strategy 2016‒2020. The manual provides guidance for managers of national leprosy programmes (or equivalent entities) to adapt and implement the Global Leprosy Strategy according to the epidemiological burden in their own country.

In March 2017 The Global leprosy programme published its Monitoring and Evaluation Guide–Global leprosy strategy 2016-2020 The Global Leprosy Programme is taking the lead in expanding the network for surveillance of leprosy drug resistance, defined as a key intervention under the Global Leprosy Strategy.