LEISHMANIASIS

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LEISHMANIASIS

• Leishmania spp
• protozoan parasite of mammals
• over 23 species
• Polymorphic promastigote and amastigote
• largely zoonotic
• all species exhibit similar morphologically
• differ in clinical presentation, biological
  features, or serological characteristics

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LEISHMANIASIS

• Leishmania spp. (promastigote stage)

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LEISHMANIASIS

• Cutaneous/mucosal form (CL, MCL)
• Causative agents Leishmania tropica, L. major,
  L. aethiopica, L. mexicana, L. braziliensis
• Other names of disease chiclero ulcer, uta,
  oriental sore, Delhi boil

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LEISHMANIASIS

• Visceral form (VL)
• Causative agents Leishmania donovani, L.
  infantum, L. tropica, L. chagasi
• Other names for disease kala-azar, dum dum
  fever
• chronic intracellular disease

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LEISHMANIASIS

• Epidemiology
• Occurrence prevalent in four continents
  endemic in 88 countries
• Incidence (globally)
• CL - 1-1.5 million cases
• VL 0.5 million

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LEISHMANIASIS
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LEISHMANIASIS
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LEISHMANIASIS

• Epidemiology
• Reservoir humans, wild animals, domestic dogs
• Vector female sandfly (phlebotomine species)
• Transmission
• bite of female sandfly (only female transmits
  vector)

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LEISHMANIASIS
Life cycle
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LEISHMANIASIS

• Vector female sandfly

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LEISHMANIASIS

• Vector female sandfly

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LEISHMANIASIS

• Clinical features Cutaneous (CL) and
  mucocutaneous (MCL)
• Incubation period 7 days to many months
• Primary lesion single or multiple indolent
  ulcer(s)
• may heal spontaneously in weeks to months but can
  persist for a long period (years)
• may disseminate to mucosal lesions (espundia)
  years after cutaneous lesions heal, can cause
  severe destruction and permanent disfiguring of
  nasopharyngeal tissue

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LEISHMANIASIS

• Cutaneous Leishmaniasis

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LEISHMANIASIS

• Cutaneous Leishmaniasis

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LEISHMANIASIS
Cutaneous leishmaniasis
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LEISHMANIASIS

• Mucocutaneous leishmaniasis - before treatment

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LEISHMANIASIS

• Mucocutaneous leishmaniasis - after treatment

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LEISHMANIASIS

• Clinical features VL
• Incubation period 10 days to years
• Symptoms
• fever (undulating), hepatosplenomegaly, anemia,
  emaciation, wasting
• dermal lesions (post kala-azar or PKDL) after
  apparent cure of systemic disease
• usually fatal if untreated
• malnourishment may predispose to active disease

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LEISHMANIASIS

• Hepatosplenomegaly

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LEISHMANIASIS

• Amastigotes in liver

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LEISHMANIASIS

• Amastigotes in spleen

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LEISHMANIASIS

• Diagnosis
• direct examination of amastigotes in tissue
  scraping or biopsy (Geimsa stain)
• culture or isolation from laboratory animals
  required for species identificaiton
• serology - detection of antibodies more useful
  for visceral or mucocutaneous forms
• PCR - very sensitive
• Montenegro intradermal skin test (not available
  in US) - positive with established disease, not
  early in disease

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LEISHMANIASIS

• Diagnosis
• Skin biopsy (L. mexicana mexicana, HE stain ) -
  amastigotes lining outer surface of vacuoles
  (patient from Austin, TX)

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LEISHMANIASIS

• Diagnosis
• direct smear from skin (L. tropicana minor, HE
  stain ) - amastigotes in macrophage (patient
  frequently traveled to endemic countries)

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LEISHMANIASIS

• Diagnosis
• direct smear from skin (L. donovoni, HE stain )
  - amastigotes in macrophage

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LEISHMANIASIS

• Treatment
• Antimony compounds
• meglumine antimonate (Glucantime)
• sodium stibogluconate (Pentostam)
• Amphotericin B or pentamidine (Lomidin) if
  non-responsive to antimony treatment
• Experimental
• Allopurinol (gout drug) on trial for Chagas
• Ketaconizole (fungicidal) inhibits sterol
  synthesis interferes with growht and division of
  amastigotes

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LEISHMANIASIS

• Control
• systematic surveillance for actives cases and
  subsequent treatment
• vector control - sand flies have short range,
  very susceptible to insecticide spraying proper
  screens habitat control
• reservoir control - eliminate rodent burrows,
  feral dog control in certain regions