How is leprosy transmitted?
We have learnt throughout 2020 how important it is to know how a disease is transmitted. Knowing to wash our hands, maintain social distancing and cover our mouths has helped communities across the world combat the spread of Covid-19. Understanding the transmission of leprosy will help us to combat transmission of the disease, as well as other problems associated with leprosy.
Leprosy is caught through droplets of moisture in the air coming from a person who is infectious
Scientists are still not 100 percent sure how leprosy is transmitted and there is a lot research being conducted to find out exactly how it happens. In The Leprosy Mission, our teams in Bangladesh, India and Nepal are all working on transmission studies.
Most scientists believe that leprosy is caught through droplets of moisture passing through the air from an infectious person who has leprosy, but has not been treated with multi-drug therapy (MDT). Only 1 in 10 of people affected by leprosy are infectious.
Leprosy is most often transmitted through prolonged contact with an infectious person
Leprosy is a mildly infectious disease. This means that it is rare to catch the disease after a brief encounter with an infectious person. People are most at risk of catching leprosy if they spend prolonged periods of time with an infectious person within a confined space. For example, if they spend a long time in a small room with that person.
However, even if you live with a person who is affected by leprosy and is infectious (has not received treatment) your risk of contracting the disease is low. Recent research by our team in Bangladesh showed that, over the course of a year, no more than 13 out of every 1,000 people who lived with a person affected by leprosy was diagnosed with the disease themselves.
For anyone who is worried about infection because they live in a community with recent cases of leprosy (primarily in Asia, Africa, and Latin America), all they need to do is keep an eye out for the signs and symptoms of the disease, and then get treatment, which is free and effective.
Leprosy is mildly infectious and most of the world is immune
Around 95 percent of the world population has an immune system that will prevent a leprosy infection. This means that, even if you do spend prolonged periods of time with a person who is infectious, you will not catch the disease.
Having a strong immune system normally means that a person is not susceptible to leprosy. A strong immune system primarily comes from having access to clean water and good sanitation, being able to access health care, and having a diet that provides you with the right nutrients. It is important to repeat here: around 95 percent of the world population has a strong immune system like this. Sometimes people can have a weakened immune system because of diseases that suppress immunity, genetic mutations, and certain long-term medications.
Leprosy is not something to fear
Leprosy is an infectious disease, but it’s nothing like Covid-19. We know that Covid-19 is highly contagious, and people across the world have locked themselves in their homes to protect themselves from it. In places with high rates of infection, this is a reasonable response.
Unfortunately, leprosy comes with a lot of fear around transmission, as well. The disease comes with a lot of stigma and false beliefs about curses and damaging perceptions of disabilities. People affected by leprosy are too often kicked out of their homes and communities, they are divorced and they lose their jobs. This is not a reasonable response.
As we have seen, leprosy is mildly infectious – most of the world is immune to it – and it is very simple to cure, as all it requires is a course of free medication (multi drug therapy).
By understanding how leprosy is transmitted, we not only know when we need to keep an eye out for symptoms, but we can also end the unnecessary stigma that surrounds the disease. It is not a disease to be feared.
You can see where leprosy exists in the world on this page.
The above provides details of the most common ways that leprosy is transmitted, but you can five of the most unusual things about leprosy transmission here.