About Leprosy

Leprosy is a chronic, mildly infectious disease caused by a slow growing bacillus, Mycobacterium leprae.

an elderly man sits with his damaged hand outstretched in front of him revealing

Learn about leprosy with our Q&A


What causes leprosy?

Leprosy is a disease caused by a bacillus, Mycobacterium leprae. It multiplies very slowly and the incubation period can be a number of years (on average about 5 years).

What are the symptoms?                                                                       

For many people the first signs of leprosy are pale patches of skin or numbness in the fingers or toes. This is because the disease mainly affects the nerves and skin. If left untreated, it can lead to nerve damage, loss of feeling (sensation) and paralysis of muscles in the hands, feet and face.

How can it cause disabilities?

The bacteria attack nerve endings and destroy the body’s ability to feel pain and injury.  Without feeling pain, people don’t realise when they injure themselves and their injuries can become infected. Changes to the skin also leave the person susceptible to ulcers, which if left untreated, can cause further damage, wounds and visible disfigurements to the face and limbs. If the facial nerve is affected, this can interfere with a person’s ability to blink, which can eventually cause blindness.

How is it spread? Is it contagious?

Leprosy is most likely transmitted by air through droplets from the nose and mouth, during close and frequent contacts with people who have not yet been treated. While it is spread in similar way to the common cold, it is much less infectious.

Leprosy is one of the least infectious diseases because it multiplies slowly and the vast majority of people have adequate natural immunity, so don’t contract the disease if exposed. Even when diagnosed many cases are not considered infectious, and once treatment begins, those infectious cases become non-infectious within the first week of treatment.

Can it be cured?

The good news is that most of these consequences can be avoided.  Since 1981 leprosy has been treated effectively with multi drug therapy (MDT), a combination of three drugs, which kills the bacteria and cures the person. If treated in the early stages of disease, MDT can prevent the onset of impairments and disabilities.

What is the treatment?

Multi-Drug Therapy (MDT) is a combination of three antibiotic drugs: dapsone, rifampicin and clofazimine. Dapsone has been used since the 1940s, and rifampicin and clofazimine were discovered in the early 1960s.

Treatment typically takes from six months to one year.

Is the treatment expensive?

Since 1995, MDT has been provided for free to anyone who needs it through the World Health Organisation. Originally this was funded by the Nippon Foundation, and since 2000, MDT has been funded by Novartis and the Novartis Foundation.

Is leprosy an ancient disease?

The first known written mention of leprosy is dated 600 BC. Leprosy was recognised in the ancient civilizations of China, Egypt and India.  Throughout history, people affected by leprosy have often suffered from stigma and discrimination.

But I thought it was eliminated?

The World Health Organisation declared leprosy ‘eliminated’ as a public health problem at a global level in 2005. This was based on a definition of less than one case per 10,000 people across a larger population.  This did not mean total eradication of the disease, and there were still many cases in pockets all over the world. However, once the target was reached, resources were often focused on other diseases and efforts to find and treat new cases diminished. The situation today is that there are around 220,000 new cases reported globally each year.

How many people are affected today?

Beyond the new cases that are reported annually, there are likely to be millions more living with undiagnosed leprosy.  Further, there are about 6 million people who have been cured of the disease, but experience residual effects of disability and discrimination. The majority, 81%, of all new cases occur in three countries: India, Brazil and Indonesia – which are the most highly endemic countries for leprosy.

How can it be ended once and for all?

The stigma still associated with leprosy remains a barrier to ending transmission, as people are often reluctant to get diagnosed or seek help. It can also have a devastating impact on peoples’ lives, long after they have been cured. That’s why ILEP is working in partnership with many different organisations, governments and policymakers towards zero leprosy.  We want to stop the transmission of leprosy, prevent disabilities and promote social inclusion by ending discrimination. To find out more about achieving Zero Transmission, Zero Disabilities and Zero Discrimination, visit www.triplezerocampaign.org.