Leishmaniasis is an infectious disease transmitted by sandfly bites that affects skin, mucous membranes, and internal organs. It has different forms depending on the affected areas, ranging from cutaneous lesions to systemic visceral infection. Common symptoms include skin sores, difficulty breathing, fever, weight loss, and enlargement of the liver and spleen. Treatment typically involves antimony-containing drugs, but resistance has developed in many areas. Without treatment, complications can include secondary infections and even death.