American leishmaniasis.

The origin of leishmaniasis in the New World is discussed, and the numerous forms of the disease are briefly described. The epidemological pattern of American leishmaniasis is clearly that of a zoonosis in various stages of development. Nine geographical types of cutaneous leishmaniasis are recognized, and probably others exist also; the visceral disease is of the well known Mediterranean type and of a uniform type throughout the Americas. The prevalence of human infection in the different regions is discussed with particular reference to the animal reservoirs. Disturbances of the terrain for agricultural development, road construction, etc., lead to epidemics and there is some evidence that the disease is now spreading in Latin America.