Leishmania species

MICROBIOLOGY

  • Protozoan parasite, HIV increases the risk of visceral (hepatosplenic and bone marrow) disease but not cutaneous or mucocutaneous disease.
  • Transmitted by sand fly vectors [Fig 1]. Also may be acquired through shared needles among IDUs, primarily in endemic urban settings.
    • Zoonosis: reservoirs
      • Canine: L. infantum, L. chagasi
      • Anthroponotic: L. donovani
  • Forms:
    • Visceral leishmaniasis: L. donovani (Asia), L. infantum (southern Europe, Mediterranean), L. chagasi (Brazil).
    • Cutaneous leishmaniasis: L. major and L. tropica (Old World), L. mexicana, L. amazonensis, L. peruviana, L. guyanensis (New World), L. (viania) braziliensis (cutaneous and mucocutaneous)
  • Amastigote forms are seen within macrophages; flagellated promastigote forms seen in cultures, transmitted from insect vector.
  • Leishmania and HIV co-localize in similar cells (macrophages, dendritic cells) resulting in additive immune dysfunction, especially in macrophages leading to increased immune activation.

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Last updated: May 10, 2021