Leishmaniasis (leishmaniasis) is a disease caused by protozoan parasites of the class Leishmania and spread through the bite of certain species of mosquitoes. This disease appears in three main forms: cutaneous, cutaneous-mucosal, or visceral leishmaniasis, the skin type of this The disease has symptoms such as skin ulcers. Symptoms of the skin-mucosal type of this disease are skin, mouth, and nose ulcers. In the beginning, visceral leishmaniasis has symptoms such as skin ulcers, and then symptoms such as fever, reduction of red blood cells, and enlargement of the spleen and liver appear.

The most important way to transmit the disease is the bite of an infected mosquito. Insects of the genera Phlebotomus and Lutzomyia are responsible for parasite transmission in the Old and New World, respectively. Mosquito saliva has the property of dilating blood vessels and increasing erythema and has a direct relationship with the parasite load and the size of the wound.

More than 20 species of Leishmania cause infection in humans. Risk factors include: poverty, malnutrition, deforestation, and urbanization.

The disease also occurs in other species of animals, such as dogs and rodents.