Leishmaniasis (leishmania)

Chest | Pulmonology | Leishmaniasis (leishmania) (Disease)


Description

Leishmaniasis is a disease caused by protozoan parasites that belong to the genus Leishmania and is transmitted by the bite of certain species of sand fly (subfamily Phlebotominae).

Causes and Risk factors

Most forms of the disease are transmissible only from animals (zoonosis), but some can be spread between humans. Human infection is caused by about 21 of 30 species that infect mammals. These include the L. donovani complex with three species (L. donovani, L. infantum, and L. chagasi); the L. mexicana complex with four main species (L. mexicana, L. amazonensis, and L. venezuelensis); L. tropica; L. major; L. aethiopica; and the subgenus Viannia with four main species (L. (V. ) braziliensis, L. (V. ) guyanensis, L. (V. ) panamensis, and L. (V. ) peruviana). The different species are morphologically indistinguishable, but they can be differentiated by isoenzyme analysis, DNA sequence analysis, or monoclonal antibodies.

Cutaneous leishmaniasis is the most common form of leishmaniasis. Visceral leishmaniasis is a severe form in which the parasites have migrated to the vital organs.

Diagnosis and Treatment

Visceral leishmaniasis is treated with an intravenous medication called liposomal amphotericin B. Amphotericin is generally safe but may have side effects, including renal insufficiency. In developing countries where the drug is not available, an older agent called pentavalent antimony (SbV) may be used intravenously or intramuscularly. More recently, paromomycin and miltefosine have been used.

Cutaneous leishmaniasis is not always treated. Cases with few lesions that are small and appear to be healing are sometimes simply monitored. Significant disease is treated with medications, but treatment recommendations vary with where the disease was acquired and the species of Leishmania (if known). Possible treatments include oral ketoconazole, intravenous pentamidine, or liposomal amphotericin B. ...