Leprosy (Hansen’s disease) - including symptoms, treatment and prevention

Leprosy is a bacterial infection of the skin and nerves caused by Mycobacterium leprae. Leprosy is a rare infection in Australia, found mainly in Aboriginal and Torres Strait Islander peoples from northern Australia and migrants from areas where the disease is more common.

Leprosy is a notifiable condition1

How leprosy is spread

Leprosy only causes infections in humans. The disease is probably transmitted from the lining of the nose of a person with the infection to the skin and respiratory tract of another person. Close and frequent contact is required for transmission but only a small proportion of close contacts, for example, in the same household, actually develop leprosy.

A contact is any person who has been close enough to an infected person to be at risk of having acquired the infection from that person.

Signs and symptoms of leprosy

A person with leprosy may have symptoms across a spectrum ranging from  a form of leprosy where:

  • there are many symmetrical lumps (nodules, papules and macules) on both sides of the body
  • involvement of the lining of the nose causing crusting and difficulty in breathing
  • bleeding and inflammation of the eye (keratitis and iritis).

To a form of leprosy where:

  • there are a few skin lesions with loss of feeling that are clearly marked (loss of pigment or reddish colour)
  • there is symmetrical thickening of the nerves of the arms, legs and face on both sides of the body with loss of feeling.

Complications of leprosy include permanent deformity and disability, especially of the hands, feet and face; most of which can be prevented by early treatment. Special reconstructive surgery can correct many deformities that develop.

Diagnosis of leprosy

Diagnosis can be made without laboratory tests in some cases but usually a laboratory test is required. The bacteria can be seen with a microscope in a skin smear using a special stain.

Incubation period

(time between becoming infected and developing symptoms)

Ranges from 9 months to 20 years.

Infectious period

(time during which an infected person can infect others)

People with leprosy may be infectious for as long as the person has untreated disease, however they are no longer infectious soon after starting treatment with a combination of two or three medicines (multi-drug therapy).

Treatment for leprosy

Multi-drug therapy has significantly improved treatment for people with leprosy. Most people with leprosy can be cured and do not need to be treated in hospital. The duration of therapy is usually 6 to 24 months, depending on the type of leprosy. Treatment is free.

Prevention of leprosy

  • Exclude people with leprosy from childcare, preschool, school and work until approval to return has been given by an infectious diseases physician, dermatologist, or a SA Health Communicable Disease Control Branch doctor
  • control is best achieved by the rapid elimination of infectivity in people with leprosy using multi-drug therapy
  • because close and prolonged contact is required for transmission, travellers to areas where leprosy is present have a very low risk of contracting the disease.

Useful links

1 – In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'.