Leishmania major is a protozoan parasite that causes cutaneous leishmaniasis, a disease characterized by skin sores and lesions. It is primarily transmitted to humans through the bites of infected female sandflies, particularly in regions of the Middle East, North Africa, and parts of Asia. Infection with Leishmania major can lead to various symptoms, including ulcers on the skin, which may take months to heal. While the disease is not usually life-threatening, it can cause significant morbidity and may lead to scarring. Treatment options include medications such as antimonials and miltefosine, which target the parasite.