Leishmaniasis is a parasitic disease spread by the bite of the sandfly.

Alternative Names

Kala-azar

Causes, incidence, and risk factors

Leishmania are tiny protozoa. Their parasitic life cycle includes the sandfly and an appropriate host. Humans are one of those hosts. Leishmania infection can cause skin disease (called cutaneous leishmaniasis). It can affect the mucous membranes with a wide range of appearance, most frequently ulcers . It may cause skin lesions that resemble those of other diseases including cutaneous tuberculosis , syphilis , leprosy , skin cancer ( basal cell carcinoma ), and fungus infections. Leishmania can also cause systemic disease (visceral leishmaniasis) with fatal complications. When introduced into the body by the bite of a sandfly, the parasite migrates to the bone marrow, spleen, and lymph nodes. Systemic infection in children usually begins suddenly with vomiting , diarrhea , fever , and cough . In adults, fever for 2 weeks to 2 months is accompanied by nonspecific symptoms, such as fatigue , weakness , and loss of appetite . Weakness increases as the disease progresses. The skin may become grayish, dark, dry, and flaky. The parasites damage the immune system by decreasing the numbers of disease-fighting cells so death usually results from complications (such as other infections) rather than from the disease itself. Death often occurs within 2 years. Cases of infection by Leishmania have been reported on all the continents except Australia. In the Americas, Leishmania can be found from Mexico south into the South American continent. Leishmaniasis has been reported among some military personnel returning from the Persian Gulf. (See Travelers guide to avoiding infectious diseases .)

Signs and tests

SIGNS

enlarged spleen

enlarged liver

(less common than enlarged spleen)

enlarged lymph nodes

(less common than enlarged spleen)

TESTS Systemic disease:

skin test, called the Montenegro skin test

skin biopsy

biopsy

of the spleen

bone marrow biopsy

lymph node biopsy

culture of biopsy material

indirect immunofluorescent

antibody test

direct agglutination assay

Other tests (complementary to the diagnosis)

CBC

(shows decreased cellularity of blood, pancytopenia)

hemoglobin

(shows signs of

anemia )

serum

protein (decreased)

serum albumin

(decreased)

immunoglobulins (increased)

Treatment

Antimony-containing compounds are the principal medications used to treat leishmaniasis. These include:

meglumine antimonate

sodium stibogluconate

Other drugs that may be used include:

pentamidine

amphotericin B

Plastic surgery may be required to correct disfigurement by destructive facial lesions (mucocutaneous leishmaniasis). Removal of the spleen ( splenectomy ) may be required in drug-resistant cases (visceral leishmaniasis).

Expectations (prognosis)

Cure rates are high with antimony compounds. Treatment should be accomplished before damage to the immune system occurs. Marked disfigurement may develop with mucocutaneous leishmaniasis.

Complications

facial disfigurement

fatal infections resulting from damage to the immune system

hemorrhage

Calling your health care provider

Contact your health care provider if you have been in an area endemic for Leishmania and may have been bitten by sandflies, and now have symptoms suggestive of leishmaniasis.

Prevention

Preventing sandfly bites is the most immediate form of protection. Insect repellent, appropriate clothing, screening of windows, and fine mesh netting around the bed (in endemic areas) will reduce exposure. Public health measures to reduce the sandfly population and animal reservoirs are important. There are no preventive vaccines or drugs for leishmaniasis.