NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
89
malarial parasites, and any new-comer is usually down with fever in a few weeks.
From repeated reinfection during childhood an immunity gradually becomes estab-
lished, and by the time adult age is reached the immunity is more or less perfect.
In Mian Mir, for example, we may take the average endemicity as between
50 per cent. and 60 per cent. The average spleen rate of the same children
(i. e., those up to 10 years of age) is about 75 per cent. The spleen rate being
higher than the parasite rate shows that, although in some of the children
an immunity to parasites has become established, the spleens have not had time
to regain their normal size. The spleens are of course much slower in reaching
their normal size than the parasites are in disappearing, so that although the para-
site rate may decrease rapidly with advancing age, the spleen rate may even
show an increase up to a certain limit of age. Suppose, for example, it takes ten
years of constant infection and reinfection to produce an immunity to new infec-
tions. During these ten years the spleen has been enlarged. At the end of the ten
years parasites disappear and reinfection has no effect. Then the spleen begins to
decrease in size, but it may take another ten years or more before it regains its
normal size. Up to the age of twenty, therefore, enlargement of the spleen will
be present not only in all those children who have parasites in their blood, but
also in older children in whom an immunity to parasitic infection has been estab-
lished, but whose spleens have not yet regained their normal size. After twenty,
however, we may say that the spleens of the majority will have become of normal
size, and in the adults, therefore, we shall not expect to find many enlarged
spleens. This, as a matter of fact, is what we do find, as the following figures
show:—
TABLE TO SHOW THAT IN VERY MALARIOUS PLACES A DECREASE IN THE
SPLEEN RATE OF ADULTS OCCURS AS THE RESULT OF IMMUNITY.
Place.
Age.
Number examined. Number with
enlarged spleens.
Percentage of
enlarged spleens.
Mian Mir Syce lines.
0—5
9
7
77·2
6 — 1 0
1 8
1 0
55·5
11—15
16
4
25
16—25
35
8
14·5
2 6 —4 0
74
6
8·1
Duars Rungamutty .
.
0—5
. . .
. . .
77·4
6 — 1 0
. . .
. . .
8 1 · 5
Young adults
. . .
. . .
33
Ennur
. . . .
0—5
15
14
93·3
6—10
18
16
8 8 · 8
90
These places, therefore, are, I think, exactly comparable to malarious parts
of Africa, where it is stated that enlargement of the spleen is very rare among the
adults.
Secondly, we have the regions of less intense, malaria, such as Jalpaiguri and
other places in Bengal. Here the liability to infection was not so great. The
endemic index was only 15 per cent. and in none of the children under five years
of age did we find infection. The endemic index increased instead of decreasing
with advancing age, and if immunity occurred in the adult it must have been at a
comparatively late age. As would be expected from these facts, the spleen rate
in the children under ten years of age was low; it increased rapidly with advanc-
ing age, and large spleens were very common among the adults.
TABLE TO SHOW THAT IN LESS MALARIOUS PLACES AN INCREASE IN
THE SPLEEN RATE OCCURS WITH ADVANCING AGE.
Place.
Age.
Number examined.
Percentage of enlarged
spleen.
Jalpaiguri
.
.
.
.
1 — 1 0
68
15
11—15
24
62.5
16—25
15
86
In this type of malarious region, therefore, there are certainly a larger number
of cases of enlarged spleen among the adults than in the Duars or in Mian Mir.
A number of moderately malarious places in the Central Provinces are exactly
comparable to Jalpaiguri and other places in the plains of Bengal, and support
the contention that in places which are not very malarious the spleen rate
increases with advancing age. The following table shows the results of an
examination of 1,134 children from different villages in the Central Provinces by
Mr. Basak, the civil medical officer of Wardha:—
Age of children.
Number examined.
Number with
enlarged spleens.
Percentage of
enlarged spleens.
0—1 year.
.
.
.
439
10
2 . 2
2—5 years
. . .
181
16
8 . 8
6—12 years
.
.
.
.
514
78
1 5 . 3
Captain Rogers'* figures for spleen rates of places north of Calcutta also bear
out this view. An examination of his results shows that in very malarious places
the spleen rate of adults was lower than that of the children, in slightly malari-
ous places it was much higher.
*" The relationship of the water-supply, water-logging and the distribution of anopheles mosquitoes
respectively to the prevalence of malaria north of Calcutta." Journal of Asiatic Society of Bengal, Vol.
LXIX, 1900.
91
Thirdly, we have places like Calcutta and Madras where the liability to
malaria is much less than in either of the two types of places given above. No
infection was found in any of the children under ten years of age in Calcutta,
and only 5 per cent. in Madras. No enlarged spleens were found among the
children of either place. Especially in Madras, however, a certain number of
cases of fever do occur, and the large number of cases of enlarged spleens
treated in the hospitals shows that enlargement of this organ is common among
the adults. I think the above facts are sufficient to account for the general
prevalence of enlargement of the spleen among the adults in the greater part of
India, for the greater part consists of districts where the endemic index is only
moderately high, although the liability to infection is sufficient to cause, during
a number of years, a sufficient number of attacks of malaria to bring about (in the
absence of continued treatment) a chronically enlarged spleen by the time
25—35 years of age is reached.
The value of the " spleen test " as an indication of the prevalence of malaria.
I propose to go only very briefly into this question which has lately been
the subject of much discussion. My work during the present year has shown
that even when applied to children the test is open to more serious errors as an
indication of the prevalence of malaria than we supposed at first.
The truest test of the amount of malaria and the liability to infection existing
in a place is the percentage of children (under ten years of age) infected with
malarial parasites, and the best way of finding out what value can be assigned
to an enumeration of enlarged spleens is to compare the results of our spleen
counts with the endemic indices of the places under examination.
If we do this for various places in India we shall find that we can divide
the places roughly into three types as follow:—
(1) Places in which the spleen rate in the children up to ten years of age
is much higher than the parasite rate in the same children.
Examples:—
Place.
Spleen rate,
per cent.
Endemic index,
per cent.
Rungamutty (Duars) .
•
.
•
.
83
43
Mian Mir (Artillery Bazaar).
.
. 75
35
Ennur .
.
.
.
,
.
.
.
92
54
N 2
92
(2) Places in which the spleen rate in the children up to ten years of
age is almost the same as the endemic index.
Examples :—
Place.
Spleen rate,
per cent.
Endemic index,
per cent.
Jalpaiguri
.
. . . . . .
17.7
16.1
Sakadara
.
.
.
.
.
. .
15
1 5
Digdoh .
.
.
.
. . . .
25
20
Takli .
.
.
. . . . .
15
15
(3) Places in which the spleen rate in the children up to ten years of age
is a good deal lower than the endemic index.
Examples :—
Place.
Spleen rate
p e r c e n t .
Endemic index,
per cent.
Seendra .
.
. . . . . .
0
20
Ambigheri . . . . . . .
5
25
Bighori .
.
. . . . . .
0
30
Soonegaon
.
.
. . . . .
0
8
Except in the second type of place, therefore, the spleen rate of the children
up to ten years of age is not by any means an accurate indication of the
endemic index, nor would it be possible to accurately compare the prevalence
of malaria in these three types of places by taking the spleen rates of children
of the same age. The age period at which the spleen rate most nearly approxi-
mates to the endemic index differs for each place according as the place is
more or less malarious, and if we wished, for example, to accurately compare the
prevalence of malaria in the Duars and in Jalpaiguri by the examination of
spleens, we should probably have to examine the children up to two or three
years of age in the Duars, and up to ten years of age in Jalpaiguri.
If we could exclude all the chronic cases of enlargement of the spleen from
our counts, we should of course get fairly accurate results, because acute enlarge-
ments mean a comparatively recent infection with parasites : chronic enlarg-
ments are of course no indication of the prevalence of malaria at the time
of examination, as the parasite infection which caused the enlargement may
have occurred years before. For this reason little or nothing can be learnt
regarding the prevalence of malaria from an examination of enlarged spleens in
93
adults. By the time adult age is reached, too, immunity has, in very malarious
places, come into play and affected the spleen rate. The spleen rate of the
adults in Mian Mir, for example, is only 8.1 per cent., while it is over 50 per
cent. in the certainly much less malarious places of Lower Bengal.* If, however,
we depended only on a comparison of the spleen rates of adults for our results,
we should be forced to the conclusion that these places were more malarious than
Mian Mir or than the Duars.
The factor of age is, therefore, a very important one in connection with
spleen rates.
Another factor which has to be taken into account is the season of the year
at which the spleen counts are made. I have already pointed out how the
parasite rate and the spleen rate decrease throughout part of the year in Mian
Mir, and that there is a time when the prevalence of malaria is practically nil,
although there are still a large number of enlarged spleens among the children.
If at this time we depended on the spleen rate alone we should be misled into
thinking that there was still a good deal of malaria and a moderate liability to
infection when in reality there was none.
TABLE SHOWING THE PRESENCE OF A HIGH SPLEEN RATE IN CHILDREN
WITHOUT .A CORRESPONDING PARASITE INFECTION.
Mian Mir.
Date.
Endemic index,
per cent.
Spleen rate,
per cent.
Artillery Bazaar
. . .
June 1902
5
33
Infantry Bazaar .
.
.
.
June 1902
8
26
Hospital Followers
.
.
.
June 1902
0
50
Besides the factors of age, relative immunity, and season, a fourth factor
viz., the variety of parasite, may affect the spleen counts.
Assuming, however, that the object is to obtain a rough indication only of
the prevalence of malaria in a place, the examination of the number of enlarged
spleens among the children is certainly a quick and useful test, especially if the
count is made during the "fever season." If, for example, in a village 90 per
cent. of the young children have enlarged spleens, we could certainly infer that
the place was very malarious, if only 20 per cent. to 30 per cent. have enlarged
spleens we could infer that the place was only moderately malarious, and if
only 5 per cent. to 8 per cent., that it was very slightly so.
The following conclusions may, I think, be drawn:—
(1) A high endemic index in India is always accompanied by a high
(usually higher) spleen rate.
* Captain Rogers states that the percentage of enlarged spleens among adults near Calcutta is over
70 per cent., vide Indian Medical Gazette, October 1901.
94
(2) A high spleen rate may exist in adults and in children without a
corresponding parasite infection. These are either, ( a) chronic
cases in which the parasites of the last new infection have gra-
dually died out, but which will be liable to again become infected
when opportunity occurs, or (b ) cases which from repeated infec-
tions have become immune to new infections with parasites, but
in which the spleen has not yet had time to diminish to its normal
size.
(3) The spleen rate in adults is no indication of the prevalence of
malaria. In places which are very malarious it may be very low
; i n p l a c e s w h i c h a r e o n l y s l i g h t l y m a l a r i o u s i t m a y b e v e r y h i g h
(Calcutta, etc.).
(4) Bearing in mind that the spleen is comparatively slow to enlarge and
diminish in size, the spleen rate is entirely influenced by the para-
site rate. In places where the parasite rate decreases at advan-
cing age periods, the spleen rate also does so, although in some
places an increase, up to a certain age, may occur owing to the time
taken for individual spleens to diminish to their normal size. In
places where the parasite rate goes on increasing with advancing
age ( i.e., less malarious places where no immunity is established),
the spleen rate also does so, so that while there may be no en-
larged spleens among the children, there may be many among the
adults (Madras, etc.).
95
V.—A NOTE ON THE MALARIAL PARASITES AND FEVERS OF INDIA.
A FEW brief notes on this subject may be of interest.
The three forms of parasite—simple Tertian, Quartan, and malignant
Tertian—with their corresponding fevers are prevalent in India. A fourth form
of parasite, viz., the malignant Quotidian parasite, possibly also occurs, though
it would always be difficult to be certain of this on account of its resemblance
to the ordinary malignant Tertian form.
It has generally been thought that Quartan fever is rare in India. We have,
however, met with this form of parasite more frequently than with any of the
others.
In some parts of India Quartan parasites are exceedingly prevalent; they
are in fact almost the only form met with in certain districts. In the Duars, at
least, 85 per cent. of the parasites found by us were Quartans, and both simple
Tertians and malignant Tertians were rare in these parts of India. Again, at
Ennur, near Madras, the percentage of children infected with Quartan parasites
was 81 per cent., only 5 per cent. were infected with simple Tertian parasites
and 14 per cent. with a mixed infection of simple Tertian and Quartan. No
malignant Tertian parasites were found at this place. In the Jeypur hill districts,
also, Quartan infections are very common.* It is interesting that in all these
very malarious districts Ouartan parasites should be so common, while malig
nant Tertian parasites, which one would have expected to be very prevalent in
these regions (two of them, viz., the Duars and the Jeypur State, being among
the few districts of India where Blackwater Fever is met with), should be so rare.
In Mian Mir, another very malarious region, however, Quartan parasites
are entirely absent. Simple Tertian and malignant Tertian infections are
almost equally prevalent in Mian Mir, the former being the more common.
In the plains of Bengal, and in the Central Provinces the three forms of
parasites are more evenly distributed. At Jalpaiguri, malignant Tertian para-
sites were most common, then simple Tertian parasites and then Quartans.
It was at this place also that we met with a few cases which were possibly
infections with a distinct Quotidian parasite, although from lack of time we were
unable to study a sufficient number of cases to definitely decide the question.
* Quartan infections are also common in Assam; vide " Report on the nature of Kala-Azar," by
Major Ronald Ross, I.M.S. Calcutta, 1899.
96
At Calcutta we saw simple Tertian and malignant Tertian infections
in the Military Hospital at Alipore, and one case of Quartan and one of simple
Tertian in the General Hospital. The majority of the cases treated in the hospitals
at Calcutta are, however, cases of malarial cachexia, characterised by marked
anæmia, greatly enlarged spleens with sometimes enlargement of the liver, and
irregular slight fever ranging from 99°F. to 101°F. continuing for many
weeks or months. The same class of case is very common in many parts of
India, and the diseases known under the names of kala-azar and kala-dukh
would appear to be aggravated cases of the same nature. As already men-
tioned, no parasites were found by us in 80 of these cases examined in Calcutta,
nor any other sign of recent malarial infection, and none of the cases appeared
to be influenced by quinine. One case, sent as a typical case of kala-dukh,
was examined by us in Jalpaiguri. No parasites or any signs of recent malarial
infection were found. The man afterwards died of pneumonia. I have since
examined slides sent from Assam of eleven cases of kala-azar without
finding any parasites.
One of the first things that strike one in investigating malaria in India
is the almost complete absence of typical malaria charts among the cases of
"ague" under treatment in the hospitals. If one went by the charts alone, one
would be led to believe that typical cases of simple Tertian and Quartan fevers
were almost unknown in India. As a matter of fact, many medical officers have
informed me that, though they have been a number of years in charge of hospi-
tals in India, they have never seen typical temperature charts of simple Tertian
or Quartan fever among the patients, and it appears, I think, to be the general
opinion that the "malignant" forms of parasite, producing more on less irregular
fever of varying duration, are much more prevalent in India than the "benign"
forms. In reality this is not the case, and I believe that the reason why typical
cases of ordinary malaria, and typical temperature charts, are not more frequently
seen, is that in the majority of hospitals quinine is administered very early
in almost all cases of fever. In order to diagnose a case of malaria correctly
(including, of course, the form of parasite), it is, as a general rule, necessary to
withhold quinine for a few days. In the commencement of nearly all cases
of malaria the fever is more or less irregular and often practically continuous
for the first two or even three days, until the parasites have settled down to
their regular cycle, and intermittency becomes a marked feature. During these
first two or even three days, also, it may be quite possible that parasites will
not be found in the peripheral circulation. In cases of fever, if no parasites
are found after careful search, it is, I think, unwise to give quinine, because by
doing so we not only alter the true course of the temperature chart, but also,
do away with the chance of afterwards finding parasites. If the case is really
one of malaria, to withhold quinine for a few days (in the absence of parasites.
97
from the peripheral circulation) will not endanger the case in any way, and if
the case is not one of malaria, the administration of quinine, in doses suitable
for a case of malaria, is certainly harmful. When quinine has not been given, if
the case is one of malaria, the temperature chart quickly assumes its typical
course, and even without an examination for parasites a correct diagnosis is
usually assured.
A detailed account of the cases we have examined and of the characteristics
of the parasites must be left for a later report.
I have notes of only two cases of "Comatose malaria" observed by us. One
was a case in one of the hospitals at Calcutta which had been diagnosed as
cerebro-spinal meningitis. Numerous ring forms of the malignant Tertian
parasite were found on our first examination of this case. The second case
occurred at Jalpaiguri. Almost every corpuscle in this case was infected with
one or more malignant Tertian parasites, and all the large mononuclear
leucocytes were crowded with pigment granules. This man died.
Blackwater Fever is chiefly prevalent in India in the Duars, in some parts
of Assam, and in the Jeypur State. According to Drs. Stephens and Chris-
tophers, it is quite as prevalent in the Duars as in Africa. During our
stay of only about a fortnight in the tea-planting districts of the Duars two
cases were seen by Doctor Stephens, and a third case was reported to us
on the day after our return to Jalpaiguri. A comparatively large number of the
Europeans in the Duars had had the disease at some time or other, and the
reports of a number of cases were received by Drs. Stephens and Chris-
tophers. No cases were actually seen in the Jeypur State, but reports of
several cases were received and the disease is evidently not uncommon there.
Notes of isolated cases of Blackwater Fever having occurred in other parts
of India were also received, and it is certainly more prevalent in India than has
generally been assumed to be the case.
From the examination of the cases seen in the Duars and the notes and
slides of other cases, Drs. Stephens and Christophers have not, I believe,
seen reason to alter the views expressed by them in Africa regarding the causa-
tion of Blackwater Fever. Their views have indeed been strengthened by the
Indian cases.
Their opinions regarding its causation are as follows:—*
(1) There is no evidence whatever that Blackwater Fever is caused by a
special parasite peculiar to itself.
(2) Blackwater Fever can rarely, if ever, occur except in a person who is
suffering from, or has quite recently suffered from, a malarial
* See "Blackwater Fever" by J. W. W. Stephens, M.D., in "The Lancet" March 23, 1901, also
"The Malarial and Blackwater Fevers of British Central Africa," by Drs. Stephens and Christophers,
in the Reports to the Malaria Committee of the Royal Society, 1899-1900, also the Fifth Series of the same
reports, 1901.
o
98
attack. It is malarial in origin, although in itself it cannot be
considered as an attack of malaria.
(3) Quinine is, in the great majority of cases, the immediate cause of the
Blackwater.
Although it is not common to find malaria parasites in cases of Black-
water Fever, Drs. Stephens and Christophers have been able to show (by the
large mononuclear change, and by the presence of recent pigment) the existence of
a malarial infection in all their cases. The administration of quinine alone
would be sufficient in the majority of cases to account for the absence of para-
sites from the peripheral circulation, and, in addition, it is well known that many
ordinary cases of undoubted malaria occur, in which, for several days after the
fever has commenced, and occasionally practically throughout the case, para-
sites cannot be found in the peripheral circulation. In such cases the diagnosis
can, as a rule, be accurately made by the finding of pigment in the large mononu-
clear leucocytes, or by a differential count of the leucocytes, and the diagnosis
will usually be afterwards confirmed by the finding of one or two parasites.
In addition to proving the existence of a recent malarial infection in all
their cases, Drs. Stephens and Christophers have been able to show that the
onset of the Blackwater was, in all cases, preceded by one or more doses of
quinine at an interval of from four to ten hours before the attack.
After a careful study of the evidence and cases which they have published,
one can scarcely fail to come to the conclusion, with them, that Blackwater Fever
is essentially a malarial infection, in which quinine is the most common immediate
determining cause of the attack of Blackwater.
Blackwater Fever is therefore a preventible disease. The prophylaxis con-
sists in the prevention of attacks of ordinary malaria. Complete protection from
malaria may be ensured by any individual who is willing to take the trouble to pay
scrupulous attention to the use of a good mosquito curtain at night, and to ade-
quately protect himself from being bitten by mosquitoes during the evening hours.
If these simple precautions are taken, it is quite unnecessary to use quinine as a
prophylactic. No other precautions than the use of the mosquito net and the
wearing of high boots or putties in the evenings have been used by any of us
during our tours through some of the most malarious parts of India, and none
of us have experienced a day's fever during this time. By the use of the same
precautions also, and without taking any quinine, Dr. Stephens had previously
passed two years in the most malarious parts of Africa without a single attack
of malaria. If it were possible to induce the European planters, whose lives
have to be spent in very malarious regions, to adopt the same simple precautions
from the time of their first arrival in the districts, I have no doubt that Blackwater
Fever would soon become unknown among them.