Leishmaniasis

Overview

Leishmaniasis is a parasitic disease transmitted by the bites of infected sand flies. The disease is found in approximately 88 countries, from rain forests in Central and South America to deserts in the Middle East and west Asia. Some cases have also appeared in Mexico and Texas.

Leishmaniasis not only affects people who live in countries where the disease is endemic but also poses a risk to people who travel in those areas. It is classified as a neglected tropical disease (NTD): a condition that inflicts severe health burdens on the world’s poorest people and is often overlooked by drug developers and others involved in drug access.

Signs and Symptoms

Leishmaniasis can cause the following:

• Skin and mucosal ulcers or lesions
• Swelling of the spleen and liver
• Sores that can cause permanent scaring

The disease takes several different forms. The most common form, cutaneous leishmaniasis, causes skin lesions. Some types of leishmaniasis that cause skin lesions can also affect the mucus membranes of the nose and throat. The more severe form, visceral leishmaniasis, also known as kala-azar, affects internal organs such as the spleen, liver, and bone marrow.

Leishmaniasis in the skin and mucosal form can cause scarring, deformity, and disability. Lesions may be painful if they become infected with bacteria or are near joints. Visceral leishmaniasis can progress to severe illness and death without treatment.

Causes and Risk Factors

Leishmaniasis parasites are transmitted by infected sand flies. The sand fly feeds every 5–6 days, and with each blood meal, the parasite multiplies in the stomach. The sand fly acquires the parasite after feeding on an infected person and becomes capable of transmitting infection during the second blood meal.

Cutaneous disease is most heavily concentrated in Latin America and the Middle East. Visceral disease is most concentrated in India, Sudan, South Sudan, Brazil, and the Mediterranean Basin.

Risk factors include:

• Living in or traveling to countries where the disease is endemic, including Afghanistan, Brazil, Iran, Peru, Saudi Arabia, and Syria
• Exposure to sand fly bites in endemic regions
• Immune suppression due to problems like HIV/AIDS, malnutrition, organ transplant, and chronic steroid use

Prevention Guidance

Neglected tropical diseases, including leishmaniasis, are largely preventable even without vaccines. The following steps can reduce the risk of infection while in a leishmania-endemic area:

• Limit exposed skin by wearing long sleeves and pants and consider treating clothes with permethrin.
• Apply insect repellant to exposed skin according to manufacturer instructions.
• Use pesticides (indoor residual spraying) and ultrafine mesh hang nets around beds to help prevent or reduce the risk of infection from insect-borne diseases.
• Limit outdoor activity at dawn and dusk, when sandflies are most active.

Treatment and Management

Antimony-containing compounds are the main medicines used to treat leishmaniasis.

These include:

• Meglumine antimoniate
• Sodium stibogluconate

Other medicines that may be used include:

• Amphotericin B
• Ketoconazole
• Miltefosine
• Paromomycin
• Pentamidine

Plastic surgery may be needed to correct the disfigurement caused by sores on the face (cutaneous leishmaniasis).

Find Clinical Trials

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on leishmaniasis.

Community Support

For more information, see Centers for Disease Control and Prevention (CDC) Information about Leishmaniasis.

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.

NIH conducts and supports leishmaniasis research to advance understanding of all aspects of the disease, including the different species of disease-causing Leishmania parasites, the varieties and biology of sand flies that transmit the parasites to animals and humans, and how the host immune system responds to the infection. NIH also supports development of therapeutics and vaccines.

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies.