APPENDIX VI.
KALA AZA .
By Captain W. S. PATTON, I. M.S.
Since the discovery of the Leishman Donovan body by Lieut.-Col. Leishman,
R.A.M.C., at Netly and later by Major Donovan, I.M.S., in Madras, an important
contribution to our knowledge of the parasite was made by Major Rogers, I.M.S.,
who succeeded . in observing the development of the parasite into a flagellate in
citrated splenic blood incubated at a low temperature. Captain S. R Christophers,
I.M.S., Lieut.-Col. Leishman, R.A.M.C., and Captain Statham, R.A.M.C., have
confirmed and still further added to Major Rogers' observations.
Major Rogers has recently improved his method of cultivating the parasitesby
adding a small quantity of citric acid to the citrated splenic blood and found that
the development under these conditions appears to be more uniform, so that the
majority of the parasites can be found in nearly the same stage on a given day, most
having developed flagella on the third clay.
Nothing further is known regarding the life history of this parasite, and the
important problem as to how it enters the human body has yet to be solved. Many
theories have been suggested to explain the method by which the parasite leaves
the human body. Manson and Low failing to find the parasites in the peripheral
blood, but observing them in the. liver thought the biliary ducts might possibly be
the channels by which they passed into the fæces ; later finding the parasites in the
ulcers of the large intestine concluded they might escape directly from them into the
fæces. Manson, Low, Statham and others have, however, failed to find the
parasites in the stools, and it is well known that they readily die out in cultures of
splenic blood-should these become contaminated. Manson has recently suggested
that the parasite probably leaves the body in the discharges either intestinal or
cutaneous that it is ingested by some foul feeding fly in which it u n d e r g o e s u n d e r o e s m u l t i -
plication and is then implanted in the human host by this insect by bite or bycontact
with broken skin surface. Both Christophers and Rogers have suggested that
the parasite is ingested by some blood-sucking insect, the latter mentioning the
bed-bug as a probable intermediate host, and in support of this hypothesis both
Christophers and Donovan have found the parasite in the leucocytes of the peri
- p h e r a l b l o o d .
A careful study of films of finger blood of patients suffering from Kala Azar in
the General Hospital., Madras, has shown that the parasite can be found in the
majority of cases, while in those suffering from extensive ulceration of the large
intestine they were found in large numbers. In order to test the truth of the above
hypothesis a number of feeding experiments with the common blood-sucking
insects of Madras were carried out, and at the outset it was found that the parasite
- could be recovered from the midgut of the louse Pediculus capitis and the Indian
bed-bug Cimeæ rotundatus fed on suitable cases ; in the louse, however, no develop-
ment was observed, while in the bed-bng all stages up to the mature flagellates
have been met with.
The parasites are ingested by the bug, while in the leucocytes and the majority
remain unchanged until the second day. While still lying in the degenerating
leucocytes the parasites begin to enlarge, the protoplasm increases in volume
staining deep blue with Giemsa's stain and contains many vacuoles ; at the same
time the macro-nuclei increase considerably in size and have a granular appearance,
while the micro-nuclei slightly enlarged retain their original characters. One of two
important changes may now take place in these enlarged forms ; they may either.