Leprosy: The Disease

Leprosy is the world’s oldest known communicable disease. Once affecting all of the world, it lurks in the poorest communities of the world. In our culture, the word “leper” is used to describe people who are outcast, feared and stigmatized. We no longer use this term, unfortunately, but people with leprosy live with the stigma.

The cure for leprosy, an antibiotic treatment, was discovered at Trinity College in Dublin, Ireland in the 1980’s.

We believe it is an injustice that the cure exists but millions of people cannot access it because they are too poor.

Here are a few facts about leprosy: 

  • Also known as Hansen’s disease, leprosy is a chronic infection passed through droplets in the air. 
  • The infection is caused by Mycobacterium leprae.
  • The bacteria affect the nervous system, attacking the hands, feet and face.
  • Left untreated, leprosy causes life-long disability through ongoing ulcers, bone reabsorption and tissue reduction. 
  • The stigma of leprosy is real, casting people  affected by the disease out of their community.
  • Leprosy is curable. When diagnosed and cured in early stages, leprosy leaves no scars. 

Leprosy: I didn’t know it still existed

You may have heard that the The World Health Organisation (WHO) declared leprosy eliminated in the year 2000. That does not mean that it has been eradicated. It simply means that official statistics show that less than 1/10,000 people suffer from the disease. Without surveying for the disease, only people who present at a health facility are diagnosed and treated. These are the only people represented in the statistics. Because leprosy is stigmatised in poor and remote areas,  many people are afraid to or unable to access the care that they need. These people, left untreated, are condemned to lives of needless disability and suffering. They remain a source of infection in their communities. 

Over the past 20 years, up to 15 million people have been infected but have neither been diagnosed nor treated.  Eradicating leprosy means zero new cases and no
more suffering. We need your help to make that happen.


Measuring the number of people effected by leprosy is fraught with challenges:

1. Even within countries where “elimination has been achieved,” there are regions that are saturated with high rates of new cases of leprosy. In 2017, WHO listed 22 Priority Countries where high endemic areas can be found. The statement seems ironic for a disease already declared eliminated.

2. Leprosy is a disease of the poor, most of whom do not have access to health care. People infected, but untreated, continue to spread the disease. Without an official diagnosis, these people are not counted. They do not contribute to the official numbers reported in country or by WHO.

3. People affected by leprosy must present at a health facility to be tested and diagnosed. In remote and poor regions neither the health education nor the necessary resources are available. This increases the likelihood of developing disability.

4. In the year 2000 the treatment period was decreased from 24 to 12 months. This has artificially reduced the number of active cases. Leprosy treatment depends on the intensity of the infection. While many cases can be treated in 12 months, not all can be. Without proper follow-up, patients return to their communities, still carrying the infection.

5. Changes in the definition of who has leprosy has reduced the number of cases annually. But, only as a statistic, not in reality! Pre-1988 cases included people diagnosed, in treatment, needing medical assistance and living with disabilities. Today it includes only people in treatment.

solving the problem


Note the sharp drop in the number of cases between 2000 and 2006. This represents the discontinuation of surveying communities for leprosy and changes in measurement.

When campaigns to detect leprosy are organized in regions that are known to have leprosy, we see a sharp rise in cases. 

The graph shows that when cases of leprosy were looked for through detection campaigns (between 1991 and 2000), high numbers of cases were detected, peaking at 800, 000. The number of new cases has fallen to between 200, 000 and 250, 000 per year since the year 2000. This drop in new cases has nothing to do with the prevalence of the disease decreasing but is brought about because there is no active case surveillance.