Leishmania

Members of the Leishmania genus are obligate, intracellular vector-borne protozoa which can cause a wide spectrum of disease, ranging from asymptomatic infection to diffuse or localized cutaneous leishmaniasis (CL), visceral leishmaniasis (VL) and mucocutaneous leishmaniasis (MCL). Leishmania spp. are members of the order Kinetoplastida due to the presence of a kinetoplast. Leishmaniasis remains a neglected tropical disease, with approximately 310 million individuals at risk for contracting the infection, 12 million people currently infected, and an annual incidence of 2 million new infections. There are two major forms of the parasite, the extracellular promastigote found in the sand fly and the intracellular amastigote found in vertebrate hosts. While the classic mode of Leishmania transmission is through the bite of an infected sand fly, infection through contaminated needles shared among intravenous drug users, blood transfusion, organ transplantation and vertical transmission have also been documented, albeit rarely.