Kala-azar

Definition

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

Alternative Names

Causes

Leishmania are tiny protozoa (a simple living organism). Their parasitic life cycle includes the sandfly and the right host. Humans are one such host. Leishmania infection can cause skin disease (called cutaneous leishmaniasis), which can also affect the mucous membrane. The infection can also cause  systemic (throughout the body) disease.

Affected mucous membranes can have a wide range of appearances, most frequently ulcers. Leishmaniasis may cause skin lesions that resemble those of other diseases including cutaneous tuberculosis, syphilis, leprosy, skin cancer

Leishmania systemic disease, called visceral leishmaniasis, can have fatal complications. When introduced into the body by the bite of a sandfly, the parasite migrates to the bone marrow, spleen, and lymph nodes. The parasites damage the immune system by decreasing the numbers of disease-fighting cells.

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. 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 continents except Australia (see Travelers guide to avoiding infectious diseases). In the Americas, Leishmania can be found in Mexico and south into the South American continent. Leishmaniasis has been reported among some military personnel returning from the Persian Gulf.

Symptoms

• history of exposure to the bite of sandflies
• history of being in an area known for leishmaniasis

Systemic illness (visceral leishmaniasis):

• Fever, persistent, long duration (weeks), may cycle irregularly
• Night sweats
• Fatigue
• Weakness
• Appetite loss
• Weight loss
• Abdominal discomfort, vague
• Vomiting (children)
• Diarrhea (children)
• Cough (children)
• Scaly skin
• Gray, dark, ashen skin
• Thinning hair

Skin disease (cutaneous leishmaniasis):

Symptoms on the skin include:

• Macule or papule, erythematous
• Skin ulcer, forms at site of original lesion
• Ulcer heals very slowly over a matter of months
• Smaller lesions may form around the ulcer (satellite lesions)

Symptoms on mucous membranes include:

• Nasal stuffiness
• Runny nose
• Nosebleed
• Ulcers and erosion of tissue (mouth, tongue, gums, lips, nose, nasal septum)
• Swallowing difficulty (dysphagia) with esophageal involvement
• Breathing difficulty, with tracheal involvement

Exams 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 (testing to see if microorganisms grow) of biopsy material
• Indirect immunofluorescent antibody test
• Direct agglutination assay

Other tests (complementary to the diagnosis)

• CBC (shows decreased cellular material in the blood)
• Hemoglobin (shows signs of anemia)
• Serum protein (decreased)
• Serum albumin (decreased)
• Immunoglobulins (antibodies; 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).

Outlook (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.

Possible Complications

• Facial disfigurement
• Fatal infections resulting from damage to the immune system
• Hemorrhage

When to Contact a Medical Professional

Contact your health care provider if you have symptoms suggestive of leishmaniasis following a visit to an area where Leishmania is endemic.

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.