Leishmaniasis

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  • Epidemiology
    • World-wide prevalence 12 million
    • Incidence 2 million new cases anually
      • Approximately 100 endemic countries
  • Etiology
    • Leishmania parasite
    • intracellular protozoan parasites
  • Transmission
    • Vector: female sandflies of genus Phlebotomus
    • Humans are accidental hosts
    • When the fly bites, it injects the Leishmania parasite in its flagellated stage prosmastigote), which invades the skin’s macrophages, losing its flagellum and transforming into a non-flagellated stage (amarstigote)
  • >20 different Leishmania species
    • Non American (old world) species
      • Mediterranean basin, the middle east, the horn of Africa and the Indian subcontinent
        • L. major, L. infantum, L. tropica, L. donovani, L. aethiopica
      • Predominantly cause self-limiting ulcers
    • American (new world) species
      • Middle and south america
        • L. amazonensis, L. chagasi, L. mexicana, L. naiffi, L. braziliensis, L. guyanensis, L. panamensis
      • Can be severely destructive and even cause death, mostly in relation to MCL disease
  • Main clinical manifestations
      • 💡
      Clinical manifestation is depending on the causative (sub)species and the host’s immune response
    • Classification
      • Localized cutaneous leishmaniasis
        • Ulcerative form known as “wet” is the most common
      • Muco-cutaneous leishmaniasis
        • Also known as espundia
      • Visceral leishmaniasis (kala-azar, black fever)
        • Etx: Leishmania donovani in Asia or L. infantum in Mediterranean basin, the middle east and the new world
        • 100% mortality if left untreated
        • Hepatosplenomegaly
        • Pancytopenia
        • May have Post-kala-azar dermal manifestations
      • Diffuse cutaneous
    • Clinical forms
      • Oriental sore (red, painless papular lesion)
        • May be ulcerative, crusted, vegetative, inflammatory, lupoid
        • Other names exist in other regions: chiclero ulcer (Mexico), pian-bois (Guyana), uta (Peru)
      • Sporotrichoid form
      • Recidivans
        • Reappearance of active skin lesions at the edge of a previous scar (up to 15 years after)
      • Post-kala-azar leishmaniosis
        • Dermal lesions following visceral leishmaniosis
        • Polymorphic hypopigmented macules or multinodular
      • Disseminated (≠ diffuse)
        • Multiple papulonodular lesions throughout the body after localized cutaneous leishmaniosis
      • HIV associated cutaneous leishmaniosis
        • Immunossupression favors visceral leishmaniosis
  • Diagnosis
    • Biopsy
      • Leishmania parasites detected in cytoplasm or in free state
      • Polymorphic inflammatory granuloma
      • May-Grunwald-Giemsa (MGG) stain allows visualization of Leishmania bodies
    • Culture
      • Novy-MacNeal-Nicolle (NNN) or Roswell Park Memorial Institute (RPMI) medium
    • PCR on biopsy
  • Treatment
      • 💡
      Always consult the local guidelines and adjust after Leishmaniasis subspecies
    • Local therapy
      • Few (and small) lesions
      • Not associated with MCL or VL
      • Examples: intralesional antimony, cryotherapy monotherapy, heat therapy
    • First line:
      • Pentavalent antimonials
        • Sodium stibogluconate - pentostam
        • Meglumine antimoniate - glucantime
    • Alternative treatment regimens
      • Miltefosine, pentamidine isethionate, amphotericin B, antifungal agents (eg. ketoconazol, fluconazol, itraconazol, paromomucin franulocyte macrophage colony stimulating factor and heat therapy or cryotherapy
      • Combination of therapy
    • Prevent insect bites
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