Frequently Asked Questions About Hansen’s Disease

Hansen's disease (HD), also known as leprosy, is a complex bacterial infectious disease that responds well to treatment and, if diagnosed and treated early, does not cause disability. Unlike many other infectious diseases, it is not highly contagious, and around 95% of the human population is naturally immune.

The Hansen's disease bacteria infect skin and sometimes other tissues, including eyes, mucus membranes of the upper respiratory tract (nose), and testes. Hansen's disease almost always involves the peripheral nerves. If untreated, nerve damage can result in permanent disabilities of hands and feet and blindness. Early diagnosis and treatment are the keys to preventing Hansen's disease-related disabilities. A person with HD can continue to work and lead an active life.

Family members living with a person who has the disease but is not being treated are at the greatest risk. A spouse is the least at-risk family member while genetically related members like children, parents, brothers, or sisters are at a higher risk. This could be because of genetic susceptibility to the disease and/or because of prolonged contact with the infected individual.

Hansen's disease is not typically passed on from a mother to her unborn baby during pregnancy. Neither is it transmitted through sexual contact.

Yes. However, it is not acquired from casual contact such as shaking hands, sitting next to someone on a bus, or sitting together at a meal. Hansen’s disease is far less contagious than other infectious diseases. Around 95 percent of the human population has a natural immunity to the disease. Healthcare workers rarely contract Hansen’s disease. Most cases of Hansen’s disease respond well to treatment and become non-infectious within a very short time.

Hansen’s disease is curable using antibiotics.

Treatment regimens differ depending upon the form of the disease (see Treatment Guidelines). The National Hansen’s Disease Program recommends treatment for one or two years, depending on the form of the disease.

Treatment rapidly renders the disease non-communicable by killing most bacilli within a few days. However, these dead bacilli are cleared from the body very slowly so dead bacilli may continue to be found in skin biopsies for several years.

Treatment rapidly renders the disease non-communicable by killing nearly all the bacilli within a few days. These dead bacilli are then cleared from the body slowly, within a variable number of years, so that these dead bacilli may continue to be found in skin biopsies for several years.

The National Hansen’s Disease Program in Baton Rouge, Louisiana, is the only institution in the U.S. exclusively devoted to Hansen’s disease. The center functions as a referral and consulting center with related research and training activities. Most patients in the U.S. are treated at National Hansen’s Disease Program’s Ambulatory Care Clinics in major cities or by private physicians. See more on National Hansen’s Disease Ambulatory Care Clinics.

People with Hansen’s disease in the U.S. can receive Hansen’s disease medications at no cost through their own doctor or through the National Hansen's Disease Program’s Ambulatory Care Clinic closest to them.

For further information, phone the National Hansen’s Disease Program at 1-800-642-2477.

Because the bacteria that cause Hansen's disease like the cooler parts of the body, the skin and its nerves are affected. This can cause dryness and stiffness of the skin. In some cases, affected nerves can swell, causing pain. There can be loss of feeling and weakness in the muscles of the hands or feet.

Hansen's disease in the U.S. is relatively rare, but between 150 to 200 new cases are reported each year.

The first signs of Hansen's disease are usually pale or slightly red areas or a rash on the trunk or extremities. Frequently, but not always, there is an associated decrease in light touch sensation in the area of the rash. A loss of feeling in the hands or feet may also be the first sign of Hansen's disease. These changes in sensation are a valuable clue to diagnosis. Nasal congestion may be a sign of infection, but infection is more often associated with changes of the skin on the face, such as thinning of the eyebrows or eyelashes.

Your doctor can make the diagnosis by doing a test called a skin biopsy, which reveals a particular pathologic pattern and demonstrates the specific "red" staining bacteria. At the National Hansen’s Disease Program, modern molecular biology tests on skin biopsies are also used to diagnose the disease. By far the most important diagnostic tool is the biopsy of the rash. There are no reliable ‘blood tests’ for the diagnosis of Hansen’s disease. Although some blood tests are promoted in some countries, they are not used in the United States.

People with Hansen's disease who are diagnosed and treated early avoid many of the complications associated with the disease and experience no disfigurement or disability. Problems with insensitive fingers or toes can be prevented by avoiding injury and infections to these areas, and by taking the Hansen's disease medicines. In many cases, disfigurement happens due to delayed diagnosis leading to delayed management of the disease.

The most commonly accepted theory is that Hansen's disease is transmitted human-to-human by way of the respiratory tract, since large numbers of bacteria can be found in the nose of some untreated patients. The degree of susceptibility of the person, the extent of exposure, and environmental conditions are probably important factors in transmission. In the United States, armadillos may be a source of infection.

If you think you have been exposed to Hansen's disease, do not panic. Most people have natural immunity and there is no need for prophylactic medication. Consult with your physician.

We do not yet have a vaccine or a blood or skin test that will tell if you have been exposed or if you have pre-clinical disease, although these are active areas of research at the National Hansen's Disease Program.

Household contacts of people with Hansen's disease should have a thorough physical examination annually for five years. If they develop a questionable skin rash, they should notify their healthcare providers and have the skin rash biopsied to determine whether Hansen’s disease is present.

Globally around 200,000 new cases are reported annually. In the United States, between 150 – 200 new cases are diagnosed each year.

Hansen’s disease can have different clinical forms depending on the individual’s immune response to the bacteria. Clinical classification of this disease is complex and, in most cases, requires a skin biopsy. Skin biopsies can be evaluated at the National Hansen’s Disease Program at no charge. There are two polar forms. Tuberculoid, where there are few lesions (rashes) with very few bacteria in them, and lepromatous, where there are many skin lesions with a large number of bacteria in them. There are multiple forms in between these two polar forms of the disease. Another way to classify the disease is by counting the number of skin lesions. If there are five or fewer lesions, then it is classified as paucibacillary (few bacilli, PB), and if there are more than five lesions, then it is classified as multibacillary (many bacilli, MB).

Unfortunately, the rash caused by Hansen's disease often resembles other skin diseases. Hansen's disease is a slowly-developing chronic infectious disease, and 2 to 10 years may elapse before clinical signs and symptoms appear. Also, in many tuberculoid or paucibacillary cases, the specific "red" staining bacteria may not be found in the skin biopsy, making it difficult to diagnose.

Additionally, most private sector physicians in the U.S. lack experience with this disease, and do not consider a diagnosis of Hansen's disease, even in a patient who has lived in or migrated from a country where Hansen's disease is prevalent. Often a patient sees several physicians before the correct diagnosis is made, delaying the initiation of treatment even more.

Some patients experience what is called a “reaction” before, during, or after treatment. This is a response of the immune system to dead or dying bacteria and can cause worsening of the rash or a painful neuritis which can affect sensation and/or strength. Reactions are not a sign that the antibiotic treatment isn’t working.

Reactions can be mild or severe. More severe reactions can be harmful to nerves and should be promptly treated by a physician. If you think you are having a reaction of any type, it is best to notify your physician to decide on appropriate treatment. Because the immune system may take years to clear the dead bacteria, reactions may flare up well after antibiotic treatment is complete.