76 LEISHMAN BODIES AND LEISHMANIASIS 



vertebrates and are now normal parasites of them, and others, 

 as already shown, if accidentally introduced may be able to 

 multiply sufficiently to cause local or temporary sores, or even a 

 fatal infection. 



All the species of hsemoflagellates which normally live in warm- 

 blooded animals in the form of Leishman bodies are grouped 

 together in the genus Leishmania. A number of human diseases 

 are known to be caused by them. Kala-azar of southern Asia, 

 already mentioned, is the most severe one. A similar disease, 

 infantile kala-azar, occurs around the Mediterranean, especially 

 in children. There are also a number of Leishmanian diseases 

 which, instead of causing constitutional disturbances, cause sores- 

 or ulcers on the skin or mucous membrane. One type, oriental 

 sore, also called by various local names, is widespread throughout 

 many tropical countries, especially southern Asia and around the 

 eastern end of the Mediterranean, and possibly in tropical South 

 America. It causes temporary sores on the skin, chiefly of the 

 exposed parts of the body; the sores may or may not ulcerate. 

 In South America there occurs a much more vicious type of 

 the disease in which the skin sores are followed by ulcers spreading 

 over extensive areas of the mucous membranes of nose and mouth, 

 often resulting fatally. A parasite, Aphfhomonas infestans, be- 

 lieved to be allied to Leishmania, has recently been described by 

 Stauffacher as the cause of foot-and-mouth disease. 



The clinical manifestations of these ulcers and sores on the skin 

 or mucous membranes are extremely variable and indicate the 

 possibility of there being a number of different species or at least 

 varieties of Leishfnania causing them. There are some parasi- 

 tologists who believe that all the different kinds of Leishmani- 

 asis — internal, cutaneous or mucosal — are caused by different 

 strains of the same species, while others believe in the existence 

 of several species. Usually four species are recognized, as fol- 

 lows: Leishmania donovani, causing kala-azar; L. infantum, 

 causing infantile leishmaniasis; L. tropica, causing cutaneous 

 sores; and L. americana (brasiliensis) , causing sores or ulcers of 

 long duration on the skin and mucous membranes. However, 

 until we are familiar with the adult forms of all the various types 

 of Leishmania, and know more about their life histories, we can 

 only guess at their classification. 



