Visceral leishmaniasis. View of a young boy suffering from visceral leishmaniasis (kala-azar). He has the enlarged liver and spleen (hepatosplen- omegaly), and muscle wastage associated with this condition. This tropical disease is caused by Leishmania sp., a parasitic protozoan. Leishmaniasis is transmitted by bites from infected sand-flies. This is the more serious form which causes fever and, without treatment, sometimes even death. However drug treatment is very effective. Photographed in Sudan.