Leishmania

Summary

Leishmania is a family of protozoan intracellular parasites that infect and replicate inside the macrophages of their host. These parasites are transmitted through sandfly bites and can cause patients to present with either cutaneous or visceral forms of disease. While patients with cutaneous leishmaniasis may experience painless skin ulcers, those with visceral leishmaniasis tend to have more severe multi-organ involvement. For example, these patients might experience symptoms like darkened skin, hepatomegaly, splenomegaly, and pancytopenia. Leishmaniasis is commonly diagnosed through biopsies that reveal amastigotes inside the macrophages of infected patients. For treatment, amphotericin B is the primary drug used for both types of the disease, while stibogluconate is commonly prescribed for those with visceral leishmaniasis. 

Key Points

• Leishmania spp.
  • Characteristics
    • Family of obligate intracellular protozoan parasites
  • Transmission
    • Transmitted by bite of sandfly
  • Presentation: Leishmaniasis
    • Visceral leishmaniasis
      • Darkened skin
      • Splenomegaly
      • Hepatomegaly
      • Pancytopenia
    • Cutaneous leishmaniasis
      • Painless ulcers
  • Diagnosis
    • Biopsy of lesions or infected organs
      • Macrophages filled with amastigotes (FA)
  • Treatment
    • Amphotericin B
    • Paromomycin, Pentamidine
      • Mainly used for cutaneous leishmaniasis
    • Stibogluconate, miltefosine
      • Mainly used for visceral leishmaniasis