visceral leishmaniasis

(redirected from black sickness)
Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.

leishmaniasis

 [lēsh″mah-ni´ah-sis]
any disease due to infection with Leishmania.
American leishmaniasis forms of cutaneous leishmaniasis and visceral leishmaniasis found in the Americas.
cutaneous leishmaniasis an endemic disease transmitted by the sandfly and characterized by the development of cutaneous papules that evolve into nodules, break down to form ulcers, and heal with scarring. It has been divided into Old World and New World forms, and the Old World form is subdivided into urban and rural types. The Old World form is caused by organisms of the Leishmania tropica complex; the New World form is caused by organisms of the L. mexicana and L. viannia complexes. It is endemic in the tropics and subtropics, and has been called by various names such as Aleppo boil, Delhi sore, Baghdad sore, and Oriental sore. Treatment consists of injections of pentavalent antimonial compounds. Antibiotics are used to combat secondary infection. Simple lesions may be cleaned, curetted, and left to heal.
cutaneous leishmaniasis, diffuse a rare chronic form of cutaneous leishmaniasis caused by Leishmania aethiopica in Ethiopia and Kenya, L. pifanoi in Venezuela, and species of the L. viannia and L. mexicana subclass in South and Central America, respectively, in which the lesions resemble those of nodular leprosy or of keloid. Pentavalent antimonial compounds are useful in some forms, while others are antimony-resistant. The prognosis for a complete cure is not good; relapses are common.
mucocutaneous leishmaniasis a disease endemic in South and Central America caused by Leishmania viannia, marked by ulceration of the mucous membranes of the nose, mouth, and pharynx; widespread destruction of soft tissues in nasal and oral regions may occur. Called also espundia. Treatment consists of injections of pentavalent antimonial compounds.
leishmaniasis reci´divans a prolonged, relapsing form of cutaneous leishmaniasis resembling tuberculosis of the skin; it may last for many years.
visceral leishmaniasis a chronic, highly fatal if untreated, infectious disease endemic in the tropics and subtropics, caused by the protozoon Leishmania donovani. Sandflies of the genus Phlebotomus are the vectors. Called also kala-azar.
Symptoms. Symptoms are usually vague, resembling those of incipient pulmonary tuberculosis; the disease is often confused with malaria. There may be fever, chills, malaise, cough, anorexia, anemia, and wasting. The Leishmania organisms multiply in the cells of the reticuloendothelial system, eventually causing hyperplasia of the cells, especially those of the liver and spleen. Diagnosis is confirmed by demonstration of the parasite.
Treatment. Two groups of compounds are recommended: pentavalent organic antimonials, such as sodium antimony gluconate, and aromatic diamidines, such as pentamidine, if the antimonials are ineffective. Rest is prescribed for patients debilitated by anemia. A decrease in white cell count (leukopenia) often accompanies the disease, and therefore the patient's resistance to secondary infections is lowered. In some cases transfusion may be necessary to bring blood values back to normal. The patient is given a well balanced diet and liberal amounts of fluids. Special mouth care and attention to the skin are necessary to avoid complications.

vis·cer·al leish·man·i·a·sis

1. a chronic disease, occurring in India, China, Pakistan, the Mediterranean littoral, the Middle East, South and Central America, Asia, and Africa caused by Leishmania donovani and transmitted by the bite of an appropriate species of sandfly of the genus Phlebotomus or Lutzomyia; the organisms grow and multiply in macrophages, eventually causing them to burst and liberate amastigote parasites, which then invade other macrophages; proliferation of macrophages in the bone marrow crowds out erythroid and myeloid elements, resulting in leukopenia, anemia, splenomegaly, and hepatomegaly, that are characteristic, along with enlargement of lymph nodes; fever, fatigue, malaise, and secondary infections also occur; different strains of L. donovani occur; L. infantum in Eurasia, L. chagasi in Latin America.
2. visceral leishmaniasis caused by L. tropica, cultured from bone marrow aspirates of some military patients following the Gulf War.

visceral leishmaniasis

See kala-azar.

vis·cer·al leish·ma·ni·a·sis

(vis'ĕr-ăl lēsh'mă-nī'ă-sis)
A chronic tropical disease caused by Leishmania donovani (less commonly, other species) and transmitted by the bite of a sandfly of the genus Phlebotomus or Lutzomyia; the organisms grow and multiply in macrophages, which eventually burst and liberate amastigote parasites, which then invade other macrophages; proliferation of macrophages in the bone marrow causes crowding out of erythroid and myeloid elements, which results in leukopenia, as well as anemia, splenomegaly, and hepatomegaly, which are characteristic, along with enlargement of lymph nodes; fever, fatigue, malaise, and secondary infections also occur.
Synonym(s): kala azar.

leishmaniasis

(lesh?ma-ni'a-sis) [ Leishmania + -iasis]
Any of a group of related chronic parasitic diseases of the skin, viscera, or mucous membranes, caused by species of the genus Leishmania. Leishmaniasis has occurred in epidemics but occurs mostly as an endemic disease in Asia, Africa, Latin America, and the Middle East; U.S. military personnel overseas may be infected. One type of leishmaniasis, kala azar, causes visceral infection and involves the mononuclear phagocytic system, causing inflammation and fibrosis of the spleen and liver. It can be fatal if untreated. Mucosal leishmaniasis infection produces mutilating lesions that destroy the mucosa, esp. in the larynx, anus, and vulva. In the two cutaneous forms of leishmaniasis, multiple skin ulcers form on exposed areas of the face, hands, arms, and legs. These are not painful or contagious but, if left untreated, can leave permanent, disfiguring scars. Leishmania organisms infect and reproduce inside macrophages and are controlled by T-cell–mediated response. The strength of the patient's immune system determines the severity of the disease. See: kala azar

Patient care

There is no vaccine against Leishmania. To prevent infection during exposure to sandfly vectors, topical repellants containing 30% to 35% N, N-diethyl-3-methylbenzamide (DEET) should be applied to the skin; and permethrin should be used to impregnate clothing, uniforms, bed netting, and screened enclosures. These measures also protect against infections caused by other biting insects, e.g., malaria.

Treatment

Drugs used to treat leishmaniasis include amphotericin B, miltefosine, paromomycin, and sodium stibogluconate.

American leishmaniasis

Mucocutaneous leishmaniasis.

cutaneous leishmaniasis

An ulcerating, chronic, nodular skin lesion prevalent in Asia and the tropics and due to infection with Leishmania tropica. Synonym: Aleppo boil; Baghdad boil; Delhi boil; Oriental sore; tropical sore
Enlarge picture
MUCOCUTANEOUS LEISHMANIASIS

mucocutaneous leishmaniasis

A form of cutaneous leishmaniasis, involving principally the nasopharynx and mucocutaneous membranes, found in parts of Central and South America. The causative organism is Leishmania braziliensis usually transmitted by sandflies of the genus Lutzomyia.
Synonym: American leishmaniasisillustration

tegumentary leishmaniasis

Leishmaniasis that involves the skin or mucous membranes.

visceral leishmaniasis

Kala azar.