10
Para. 8
and no enlargement of the spleen or liver — except occasionally, and to such
a small degree as may be explicable on the ground of the general malarial taint
in the population.
There is no question of mistaking this disease for kala-azar of the first or
second stages ; but I think it may be confounded with kala-azar of the -third
stage — especially in those cases in which the enlargement of the organs has
diminished toward death or as a consequence of diarrhœa. The differential
diagnosis will be referred to in paragraph 41 ; and I mention the disease here
only as a leading to the following remarks.
8. The Identity of Kala-Azar Generally.—It frequently happens
that when an epidemic first appears in a locality — as, for instance, in recent
epidemics of plague or influenza — many kinds of cases are put down as
instances of the dreaded pestilence. This must be especially the case when
the actual epidemic disease has no very prominent symptoms — such, for
example, as always serve for the identification of cholera or small-pox ; and
still more so when it is a protracted disease, extending over many months,
during which it perhaps largely changes its characteristics and finally causes
death only after a long ill-defined cachexia. It would indeed be unreason-
able to expect at once complete and general identification of the disease in
outbreaks of this nature; while in one place and at one time a corroct notion
of it would be formed, it is quite possible that in others any fatal and ill-known
sickness which happens to be prevalent there at the same time will be mis-
taken as an instance of it ; and it would not be until after a considerable
period that the profession and the public would gain sufficient familiarity with
the true epidemic disease to make no more errors in regard to its identity.
Such, I cannot help thinking, has been notably the case with kala-
azar. It was peculiarly unfortunate that at the moment when the epidemic
first appeared there should have been another disease prevalent in the same
locality — a disease little studied in Assam at the period, and which, as has
just been pointed out, may be confounded with the third stage of true kala-
azar, namely, the "anaemia with dropsy."
Since then, however, the profession has had sixteen years' experience of
kala-azar ; it has been studied in many parts of Assam ; and a thorough under-
standing has been arrived at as to the general difference between the two
diseases. The result is that kala-azar is now recognised in the country to
be a fever with enlargement of the spleen and liver, and not a mere anæmia.
In the clinical description of kala-azar which I have just given, I have
been careful to express it as being applicable only to the kala-azar of the
Nowgoug District, to which my observations of the disease were confined ;
and I have expressly avoided in it all reference to descriptions already given
in existing literature—partly for purposes of comparison, and partly because
I wished to present only such evidence as I myself was able to collect. But
if this literature be now consulted — especially the Annual Sanitary Reports,
Rogers' Report and Section V of Giles's Report— it will, I think, be understood
that nay definition of kala-azar in the Nowgong District applies equally to kala-
azar generally—that is, to the kala-azar which has been described by the large
majority of medical men who have practised of late years in the affected
tracts. The almost exact coincidence between nay symptomatology and that of
Mc Naught and Rogers, who have studied the disease, the one from its first
appearance in the Garo Hills, and the other during a whole year's special inves-
tigation, will, I think, strike anyone who takes the trouble to compare our
descriptions. Under these circumstances, then, I think, I may now venture
to extend my definition to kala-azar generally, wherever it has existed in
Assam.
It is, of course, still open to anyone to say that the disease here described
is only a spurious kala-azar—that the true kala-azar is the anæmia with dropsy.
Both diseases exist side by the side in the country ; both cause a large mortal-
ity ; both are communicable from the sick to the healthy ; and I have no doubt
that serious outbreaks of the anæmia, as of the fever, have occurred in isolated
villages and tea-estates, and that the people themselves have frequently given
the name kala-azar to cases really suffering only from the anaemia. Neverthe-
less, I think with Rogers that there is no doubt that the fever is the true kala-
azar.