CHAPTER XI
L E I S H M A N I A S I S
UNDER the term " leishmaniasis " at least three diseases of man are included, viz. kala-azar, oriental sore, and espundia. These disease?, though clinically quite distinct and having each a definite topical and geographical distribution, are all associated with what optically appears to be the same organism, Leishmania. But though their respective organisms appear to be morphologically identical, it is by no means justifiable to conclude that they are specifically identical. The Leishmania form is common to many protozoa; it is merely a stage—— an immature stage—— and until the life-history is quite complete, and the natural history of the parasites of these diseases has been worked out, our judgment as to their identity or otherwise should be suspended. If it turn out to be the case that the germ causes of the various clinical forms of leishmaniasis are specifically identical, we shall have to conclude that the special pathogenic properties of these germs have been conferred on them during their extracorporeal life, especially by passage through particular animal intermediaries. Herein lies a wide field for future investigation.
I. KALA-AZAB
Synonyms.—— Tropical splenomegaly, black sickness, Sirkari disease, Sahib's disease, Burdwan fever, kaladunkh, dum-dum fever, ponos.
Definition.—— An infective disease characterized by chronicity, irregular fever, enlargement of the spleen and often of the liver, the presence in these and other organs of Leishmania donovani, emaciation, anæmia, leucopenia and relative increase of large mononuclear leucocytes, frequently a peculiar hyper-pigmentation of the skin, and a high mortality.
