Leishmaniasis is a parasitic disease caused by Leishmania parasites that are transmitted through the bites of infected sandflies. There are several different forms of leishmaniasis, including cutaneous, mucocutaneous, and visceral leishmaniasis. Symptoms can vary depending on the form of the disease but can include skin sores, fever, enlarged spleen and liver, and in severe cases can be fatal if left untreated. Leishmaniasis is mainly found in tropical and subtropical regions of the world, with the highest number of cases reported in countries such as Brazil, India, and Sudan. Treatment usually involves medication to kill the parasites and can be effective if caught early, but prevention measures such as avoiding sandfly bites are also important in controlling the spread of the disease.