Leishmaniasis is a potentially fatal parasitic disease. It’s caused by leishmania parasites. You can get it if you are bitten by phlebotomine sand flies that carry this parasite. Experts ... Leishmaniasis fact sheet from WHO: provides key facts, definition, information on transmission, risk factors, diagnosis and treatment, prevention and control and WHO response. Leishmaniasis is an infection from Leishmania parasites. Learn more about the different forms and treatment options for leishmaniasis. Leishmaniasis is a parasitic disease transmitted by sandflies and caused by different species of Leishmania. It can cause cutaneous, visceral, or mucosal lesions, depending on the parasite, host, and geographic location.