There are still some 200,000 new cases diagnosed worldwide each year and millions of people are living with some form of disability as a result of leprosy.

Untreated leprosy  can have devastating effects on individuals, causing  disability by means of permanent damage to nerves, skin, eyes, and other vital organs. The lifelong impacts of such disabilities can mean the quality of life achievable for these individuals is significantly reduced.

At MedShr we are building a global community of health care professionals with an interest in infectious diseases. We know there are many reasons why patients with chronic and slow progressing diseases such as leprosy are not being identified and treated. Join our Infectious Diseases Global Education Network to start sharing and discussing clinical cases in Leprosy. Through sharing experiences of managing such patients we can all learn from each other and improve care for patients with leprosy globally.

This video from the Indian Medical Association outlines key findings suggestive of leprosy and how you can confirm a diagnosis

What is Leprosy?

Leprosy is a chronic infectious disease caused by the bacteria Mycobacterium leprae. For many years, people with the disease were isolated and ostracized due to lack of understanding of the disease and the belief that those affected were cursed. Today, there is an effective treatment and the disease can be cured. There is no longer any justification for isolating persons with leprosy.

The disease can affect the skin, mucous membranes, and eyes, and some of the peripheral nerves. These are primarily the nerves of the hands, feet, and eyes, and some of the nerves in the skin. In severe, untreated cases, loss of sensation, muscle paralysis of hands and feet, disfigurement, and blindness may occur.

While in the past it was common in temperate climates, today leprosy is mainly confined to tropical and subtropical regions. The disease is associated with stigma, especially when deformities are present. Transmission of leprosy is thought to occur through inhalation of droplets containing the causative agent, Mycobacterium leprae. However, transmission via skin contact or other means cannot be entirely excluded. Leprosy also has a reservoir in a few animals such as armadillos which can be attributed to transmission to humans.

Up to 95% of patients exposed to the causative agent will not develop the disease[1], suggesting that host immunity plays an important role in disease progression and control. The incubation time is variable, ranging from 2 to 20 years, or longer.

When should you suspect Leprosy?

• Any patient developing a painless skin discolouration that is either pale or red could be showing early signs of leprosy

• Other symptoms such as

  • numbness of affected skin

  • muscle weakness or paralysis

  • eye problems (these present later in the disease) 

  • Any of the following social factors they live in an endemic area

  • someone in their family or close contacts has been diagnosed with leprosy

How do you confirm the diagnosis of Leprosy?

While examining a skin biopsy, taken from the affected skin or nerve, under the microscope is the best way to confirm diagnosis, this might not be possible due to lack of availability of staining material and examination equipment. The WHO recommends suspecting a diagnosis of leprosy in patients with a clinical history of long standing pale or red skin discolouration. 

There are currently no tests recommended for diagnosing latent leprosy infection among asymptomatic carriers or close contacts of patients who are suspected to have leprosy.

Classifying Leprosy

Leprosy is classified as paucibacillary (1-5 skin lesions) or multibacillary (more than 5 skin lesions or if bacilli seen under the microscope irrespective of the number of lesions), based on the number of skin lesions, presence of nerve involvement, and identification of bacilli on slit-skin smear. 

Treatment with Multi-Drug Therapy

The current WHO recommended Multi Drug Therapy (MDT) regimen consists of three medicines: 

1. Dapsone, 

2. Rifampicin, and 

3. Clofazimine. 

This treatment lasts six months for paucibacillary and 12 months for multibacillary cases. MDT kills the pathogen and cures the patient. More than 16 million leprosy patients have been treated with MDT since its introduction.

Close contacts and family members of patients diagnosed with leprosy should be offered a single dose of rifampicin as post-exposure prophylaxis. Doing so reduces the risk of them developing leprosy by 50-60% over the following 2 years. [2]

The Global Partnership for Zero Leprosy

The Global Partnership for Zero Leprosy is a coalition of individuals and organizations committed to ending leprosy, also known as Hansen’s disease. The Partnership includes members of the industry, the World Health Organization (WHO, as an observer), the International Federation of Anti-Leprosy Associations (ILEP), the Sasakawa Health Foundation, and the International Association for Integration, Dignity and Economic Advancement (IDEA). It also includes representatives from the national leprosy programmes of Brazil, Ghana, and India, the International Leprosy Association, scientific organizations, and the academic community.

Membership is open to all organizations and individuals who are committed to zero leprosy and that support the principles, objectives, and activities of the Global Partnership for Zero Leprosy.

References:

[1] Leprosy (Hansen Disease; Hansen's Disease) By Dylan Tierney , MD, MPH , Harvard Medical School; Edward A. Nardell , MD, Harvard Medical School 

[2] Leprosy Post-Exposure Prophylaxis (LPEP) programme: study protocol for evaluating the feasibility and impact on case detection rates of contact tracing and single dose rifampicin