Leishmania is notable for a large number of described species. Molecular phylogenies of Leishmania have increasingly suggested that the number of species could be too large. A recent phylogenetic analysis of the heat-shock protein 70 gene (hsp70) by Fraga and colleagues supports the existence of only eight medically relevant species compared to 17 species as defined by multilocus enzyme electrophoresis. Whether a revised classification system should be introduced for Leishmania is discussed.
