Parasite

Leishmaniasis

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Leishmaniasis, Leishmania, Kala Azar, Leishmania donovani, Visceral Leishmaniasis

  • History
  1. First reported in 1903 by both Leishman and Donovan
  • Epidemiology
  1. Incidence
    1. Worldwide: Up to 2 million new cases per year
    2. United States: Up to 100 cases/year (New World)
  2. Endemic Areas
    1. South-Central Texas
    2. Mexico and Central America
    3. South America (most common source for U.S. traveler)
      1. Most commonly contracted in Peru and Brazil
      2. No cases in Uruguay or Chile
    4. Middle East
    5. Africa
    6. Asia
  • Pathophysiology
  1. Vector
    1. Transmitted by Sandflies
      1. Old World Genus: Phlebotomus
      2. New World Genus: Lutzomyia
    2. Sandfly is 2 mm long, hairy fly
      1. Not stopped by Mosquito netting
      2. Breeds in manure, rodent holes, leaf debris
  2. Leishmaniasis Parasite
    1. Promastigote (Infectious form)
      1. Motile form of Parasite with anterior flagellum
      2. Develops in sandfly over 10 days
      3. Transmitted to humans via sandfly bite
      4. Macrophages ingest promastigote
      5. Shifts to amastigote form to endure acidic Lysosome
    2. Amastigote (Disease causing form)
      1. Non-motile, obligate intracellular Parasite
      2. Diameter up to 7 microns
      3. Results in disease and decreased cellular Immunity
      4. Sandfly ingests amastigote form when feeding
  • Types
  1. Some species cause visceral and Cutaneous Leishmaniasis
  2. Visceral Leishmaniasis (Kala Azar)
    1. Cause
      1. Leishmania donovani
    2. Description
      1. Incubation 3 months
  3. Cutaneous Leishmaniasis
    1. See Cutaneous Leishmaniasis
  • Symptoms
  1. Irregular Recurrent Fever
  2. Weakness
  3. Sweating
  4. Cough
  5. Nausea or Vomiting
  6. Diarrhea
  7. Weight loss
  • Signs
  1. Splenomegaly
  2. Hepatomegaly
  3. Lymphadenopathy
  • Labs
  1. Complete Blood Count
    1. Leukopenia
    2. Anemia
    3. Pancytopenia
  2. Liver Function Tests
    1. Hypoalbuminemia
  • Diagnosis
  • Visceral Leishmaniasis
  1. Culture, Biopsy, or buffy coat stain
    1. Skin lesion
    2. Bone Marrow
    3. Lymph Node
  • Complications
  1. Cirrhosis develops in 10% of Visceral Leishmaniasis
  2. Visceral Leishmaniasis is fatal without treatment
  • Management
  • Visceral Leishmaniasis
  1. See Cutaneous Leishmaniasis
  2. Sodium Antimony Gluconate
    1. Initial Course
      1. Adult: 10 mg/kg IV/IM qd x20-30 days
      2. Child: 20 mg/kg IV/IM qd x20-30 days
    2. Relapse
      1. Treat for 40-60 days
  3. Resistant Cases
    1. Amphotericin B 0.5 - 1 mg/kg qod for 5-25 weeks
    2. Pentamidine 3-4 mg/kg qod for 5-25 weeks
  • Resources
  1. Visceral Leishmaniasis
    1. http://www.geocities.com/donovanivl/
  • Prevention
  1. See Prevention of Vector-borne Infection
  2. Insect Repellant
  • References
  1. Pearson (1996) Clin Infect Dis 22:1-13 [PubMed]
  2. Tobin (2001) Am Fam Physician 63(2):326-32 [PubMed]