Leishmania

Abstract

Leishmania spp. are kinetoplastid protozoan parasites that infect numerous mammalian hosts, including humans, and are transmitted by the bite of female phlebotomine sand flies. Their distribution area has been broadly subdivided into the "New World"-the Americas, and the "Old World"-Africa, Asia, and Europe. The disease complex they cause, known as leishmaniosis or leishmaniasis, is endemic in large areas of the tropics, subtropics, and the Mediterranean basin, affecting more than 98 countries. More than 23 species of Leishmania have been described, most of which are zoonotic. The most important Leishmania parasite that infects domestic animals is L. infantum, also known as L. chagasi in Latin America. Dogs are very susceptible to this parasite and act as reservoirs. They may suffer from a complex and deadly syndrome, canine leishmaniosis, though many course asymptomatic infections. Cats and horses can also be infected, with milder clinical manifestations. Several serological and molecular diagnostic methods have been developed, but the gold standard is still the demonstration of parasites in stained tissue smears. Control strategies are largely limited to destruction of animal reservoirs, treatment of infected patients, and management of sand fly populations. Development of an effective vaccine against leishmaniosis is an active field of research.