Leishmaniasis

What is Leishmaniasis?

Leishmaniasis is a disease caused by protozoan parasites. Most people infected by the parasite do not develop any symptom at all in their life. There are three main forms of leishmaniasis: cutaneous, visceral or kala-azar, and mucocutaneous.

Cutaneous leishmaniasis is the most common form. It causes skin ulcers over the face, arms and legs. When the ulcers heal, they leave permanent scars. The majority of cases occur in Afghanistan, Algeria, Brazil, Colombia, the Islamic Republic of Iran, Pakistan, Peru, Saudi Arabia and Syria.

Visceral leishmaniasis (also known as kala-azar) affects internal organs of the body. This form is characterized by irregular bouts of fever, substantial weight loss, swelling of the spleen and liver, and anaemia. If the disease is not treated, the fatality rate in developing countries can be as high as 100% within 2 years. Recurrent epidemics in East Africa (Ethiopia, Kenya, South Sudan and Sudan) have caused high morbidity and mortality in affected communities.

In mucocutaneous leishmaniasis, the lesions can lead to partial or total destruction of the mucous membranes of the nose, mouth and throat cavities and surrounding tissues. Most reported cases occur in South America (Bolivia, Brazil and Peru).

How does it spread?

The parasites are transmitted by the bite of an infected female sandfly. The risk is highest in the evening and at night when sandflies are the most active.

How can you prevent it?

Currently, there is no vaccine available. The best way to prevent leishmaniasis is by avoiding sandfly bites:

• Avoid outdoor activities or visit forest areas, especially in the evening and at night;
• Wear long-sleeved tops and trousers;
• Rest in air-conditioned or well-screened rooms;
• Use aerosol insecticide indoor and use bed nets if sleeping areas are not air-conditioned or screened;
• Use insect repellents containing DEET on exposed skin and clothings. For details about the use of insect repellents, please refer to Frequently Asked Questions.
• If travelling in endemic rural areas, carry a portable bed net with fine-mesh (at least 10 holes per cm) and apply permethrin on it as well as to clothes.

How is it treated?

There is treatment available for different forms of leishmaniasis. People should consult their doctor early even if their skin lesions have already healed.