Leishmania

Leishmania is a genus of Trypaosomadic protozoa and is the parasite responsible for the disease leishmaniasis It is spread through sandflies of the genus Phlebotomus in the Old World and of the genus Lutzomyia in the New World. Their primary hosts are vertebrates;//Leishmania// commonly infects hyraxes, canids, rodents, and humans. //Leishmania// currently affects 12 million people in 88 countries. The parasite was named in 1903 after the Scottish pathologis Wiliam Boog Leishman. The origins of //Leishmania// are unclear. One possible theory proposes an African origin, with migration to the Americas. Another migration from the Americas to the Old World about 15 million years ago, across the Bering Strait land bridge. Another proposes a paleartic origin.Such migrations would entail migration of vector and reservoir or successive adaptations along the way. A more recent migration is that of //L. infantum// from Mediterranean countries to Latin America (there named //L. chagasi//), since European colonization of the New World, where the parasites picked up its current New World vectors in their respective ecologies. This is the cause of the epidemics now evident. One recent New World epidemic concerns foxhounds in the USA.