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Leishmaniasis
OVERVIEW: An infective condition caused by several species of the protozoan Leishmania. Four major clinical syndromes are recognized.
• Visceral leishmaniasis (Kala-azar, Black fever) may be endemic, epidemic or sporadic. Different forms are:
• African Kala-azar: Found in the eastern half of Africa from the Sahara in the North to the Equator. Disease of older children and young adults (10-25 years) Males > females.
• Mediterranean or infantile Kala-azar: Seen primarily in the Mediterranean area, China and Latin America. Dogs, jackals, foxes and rats are potential reservoirs. The strains responsible for the Mediterranean and American disease are sometimes referred to as L. infantum and L. chagasi respectively.
• Indian Kala-azar: Age and sex distribution similar to African Kala-azar. Humans are the only known reservoir and transmission is by anthropophilic sandflies.
• Cutaneous leishmaniasis of the old and new worlds. Characterized by one or more localized lesions on exposed areas. These ulcerate centrally and spread centrifugally. Spontaneous healing less common in new world disease. Satellite lesions and lymphadenopathy may or may not occur.
• Mucocutaneous leishmaniasis (espundia). One or more lesions on the legs which may ulcerate. In 2-5% of patients, metastatic lesions appear in the nasopharynx after months or years, and may result in painful mutilating erosions of soft tissue. Lesions may occur rarely in perineum.
• Diffuse cutaneous leishmaniasis. Extensive skin lesions , but no visceral lesions. Clinical picture may be similar to lepromatous leprosy.
System(s) affected: Gastrointestinal, Pulmonary, Hemic/Lymphatic/Immunologic, Skin/Exocrine
Genetics: N/A
Incidence/Prevalence in USA: Rare, but reported in states bordering Mexico.
Predominant age: Children and young adults. (10-25 years). Mediterranean or infantile Kala-azar - usually < 4 years age.
Predominant sex: African Kala-azar, Indian Kala-azar: Male > female
SIGNS AND SYMPTOMS: • Incubation period - about 3 months for the visceral form and 2-24 months for others
• Onset - insidious/abrupt
• Malabsorption; failure to thrive in infants and children
• Fever - nocturnal, no signs of toxemia
• Cough
• Diarrhea, GI bleeding
• Lymphadenopathy
• Splenomegaly
• Moderate hepatomegaly
• Cirrhosis, portal hypertension (in 10% of patients)
• Anemia, pancytopenia
• Cutaneous lesions, may ulcerate and heal spontaneously
• Nasal stuffiness
• Epistaxis
• Edema, cachexia and hyperpigmentation in late stages
• Hypoalbuminuria
• Hypergammaglobulinemia
CAUSES: Several species of Leishmania including L. donovani (Kala-azar), L. infantum, L. chagasi (Mediterranean and American forms), L. tropica (cutaneous form), L. major (in Middle East, Afghanistan and India), L. mexicana, L. braziliensis and others. The organisms are transmitted by female sandflies of the genus phlebotomus in the old world and Lutzomyia in the new world.
RISK FACTORS: • Children > young adults in endemic areas
• Malnutrition
• AIDS
• Incomplete therapy of initial disease
DIAGNOSIS DIFFERENTIAL DIAGNOSIS: • Malaria
• Brucellosis
• Tuberculosis
• Typhoid
• Hepatic abscess
• Lepromatous leprosy for diffuse leishmaniasis
Post Kala-azar dermal lesion (PKDL) must be differentiated from leprosy, syphilis and yaws
LABORATORY: • Demonstration of parasites in
• Bone marrow aspirate
• Splenic aspirate
• Lymph node aspirate or biopsy
• Biopsy material from suspicious skin lesions after cleaning with alcohol to reduce bacterial contamination
• The intracellular amastigote form in the macrophages, formerly known as the Leishman-Donovan (LD) body, has a characteristic pear-shaped body with a dark circular nucleus and short rod-shaped kinetoplasts
• Hypergammaglobulinemia
• Direct agglutination test detects IgM antibody which indicates acute disease
Drugs that may alter lab results: N/A
Disorders that may alter lab results: N/A
PATHOLOGICAL FINDINGS: • Marked lymphocytic infiltration
• Ulcerating lesions in the skin and mucosa of nasopharynx
SPECIAL TESTS: • Leishmanin skin test is positive 6-8 weeks after recovery in cutaneous forms, but not in diffuse leishmaniasis. It is negative in visceral leishmaniasis.
• Monoclonal antibodies or hybridization of tissue touch blots with labeled kinetoplast DNA probes used for identification of different strains of Leishmania
• ELISA highly sensitive and specific in visceral disease
• Montenegro skin test is nonstandardized and used only in epidemiological studies. It is negative in visceral leishmaniasis.
• An immunochromatographic strip test for rapid detection of antibodies to leishmania antigen K39
IMAGING: N/A
DIAGNOSTIC PROCEDURES: • Demonstration of the organism by smear or culture from aspirate or biopsy material. Novy-MacNeal-Nicolle medium or other liquid media used for cultures are maintained at 22-28°C for 21 days. Motile promastigotes can be observed microscopically.
• Speciation using monoclonal Ab or labeled DNA probes
TREATMENT APPROPRIATE HEALTH CARE: Inpatient for blood transfusions and complicating superinfections. Outpatient care once the condition stabilizes.
GENERAL MEASURES: • Bed rest, oral hygiene, and good nutrition are important.
• Transfusions for anemia and antibacterial chemotherapy for bacterial complications must supplement specific therapy.
• Periodic ECG monitoring during prolonged therapy with pentavalent antimonials.
SURGICAL MEASURES: • Adjunctive splenectomy
• Reconstructive surgery for tissue damage
ACTIVITY: Bed rest during acute stages. Level of activity dependent on severity of disease and organ systems involved
DIET: Rich nutritious diet
PATIENT EDUCATION: Explain prevention measures
MEDICATIONS DRUG(S) OF CHOICE: • Sodium antimony gluconate (Pentostam) 100 mg Sb5+/mL IV/IM: single daily dose of 20 mg/kg/day for 20-30 days
• Meglumine antimonate (Glucantime) 85 mg Sb5+/mL, same dose and duration of treatment as above, can also be used
Note: In the U.S., these drugs are available only from the CDC, Atlanta, GA 30333; emergency telephone 404-639-2888 (http://www.cdc.gov)
• Relapses and incomplete responses should be treated with the same regimen for 40-60 days. Addition of oral allopurinol (Zyloprim) 20-30 mg/kg/day in three divided doses has been effective.
Contraindications: Refer to manufacturer's profile of each drug
Precautions: Refer to manufacturer's profile of each drug. Periodic ECG monitoring is recommended during prolonged therapy.
Significant possible interactions: Refer to manufacturer's profile of each drug
ALTERNATIVE DRUGS: Relapses with drug resistant organisms are usually treated with:
• Amphotericin B (Fungizone)IV: 0.5-1 mg/kg on alternate days
OR
• Pentamidine (Pentam): 3-4 mg/kg, 3 times a week for 5-25 weeks; investigational only
• Recombinant human interferon gamma: an adjunct to pentavalent antimony in treatment failures
FOLLOW UP PATIENT MONITORING: • Follow-up at 3 and 12 months to detect relapses
• PKDL should be treated in the same fashion as the initial illness
• Periodic monitoring of ECG, liver function and renal function during prolonged therapy
PREVENTION/AVOIDANCE: • Use of pesticides (e.g., DDT) against sandflies
• Insect repellants - for travelers
• Permethrin - coated fine netting for travelers
• Early treatment of human cases
• Elimination of diseased dogs
POSSIBLE COMPLICATIONS: • Edema, cachexia, hyperpigmentation in late stages
• Superinfections and gastrointestinal bleeding may cause death in untreated patients with visceral disease (Kala-azar)
• 3-10% of the treated cases develop PKDL characterized by depigmented macules and wart-like nodules over the face and extensor surfaces of limbs
• Metastatic lesions in nasopharynx with tissue destruction in patients with mucocutaneous leishmaniasis
EXPECTED COURSE AND PROGNOSIS: With early treatment, cure rate is over 90%, though in advanced cases, mortality remains at 15-25%. In untreated cases, death occurs in 3-20 months in up to 95% of adults and 85% of children.
MISCELLANEOUS ASSOCIATED CONDITIONS: Fulminant Kala-azar has been described in association with AIDS and malnutrition
AGE-RELATED FACTORS:
Pediatric:
• Pediatric Mediterranean or infantile Kala-azar usually a disease of children under 4 years
• African or Indian Kala-azar: usually a disease of children and young adults (10-25 years)
Geriatric: N/A
Others: N/A
PREGNANCY: N/A
SYNONYMS: • Visceral leishmaniasis
• Kala-azar
• Black fever
• Dumdum fever
ICD-9-CM: 085.0 Kala-azar
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