Biology of Leishmania and Leishmaniasis

After an introduction by Mr. Furtado (Brazil), Mr. Peters (Great Britain) pointed out that four main species of leishmania, L. tropica, braziliensis, mexicana and donovani and their subspecies, are responsible for different clinical manifestations of the disease in geographically limited areas. The histological and electron-microscopic morphology of the parasite in culture and in phagocytes, reported by Mr. Klingmuller (FR Germany) do not permit the differentiation of species and subspecies. For this, the biochemical and immunological characterization is necessary. The best practicable biochemical method to distinguish parasite species and subspecies seems to be the isolation of the parasite strains in culture and their characterization by isoenzyme patterns. To this, culture of parasites should be sent to one of the several WHO international reference centres. The immunological characterization may be performed with monoclonal antibodies, using a radioimmune binding assay. The data mainly support the established main classification of New World Leishmania in species of the complex braziliensis, mexicana and donovani and their respective subspecies.