NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
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emptied, shallow drains to be swept out, and a layer of oil kept constantly on
overflow pools of the wells and other collections of water that could not be dealt
with in any other way.
During September the filling in of a large pond near the bazaar was com
pleted by the cantonment authorities.
At the beginning of September there was a temporary diminution in the
number of adult insects to be found in the houses, but at the end of the month
and during October their numbers were certainly as great, if not greater, than
during August. A few specimens of other species; viz., A. stephensi, A. pul
cherrimus, and A. fuliginosus, were also found during September. During
November the development of larvæ was less rapid and the number to be
found in the different breeding places gradually diminished. A progressive
decrease in the number of adult anopheles mosquitoes to be found in the houses
also occurred, and at the end of this month it was difficult to catch a specimen
of either species. At the beginning of December no adult anopheles mosquitoes
of any kind could be found in the houses, and from this time onwards no fresh
batches of larvæ appeared in any of the breeding places.
A similar disappearance of adults and larvæ was, however, noted in other
parts of the cantonment where no operations had been carried on.
III.—The Barracks Section.
On June 4th, anopheles larvæ were found in the shallow drains carrying off
water from the swimming baths and in the overflow water of the stand-pipes.
A sweeper was appointed to keep all the shallow drains in the vicinity of the
barracks swept out daily. On the !4th, a n o p h e l e s
l a r v æ w e r e f o u n d i n s h a l l o w
pools near the Persian wheel of the 4th barrack and in its stone water-reservoir.
On the 24th, anopheles larvæ were found in a number of kerosene oil tins which
were kept full of water near No. 8 Barrack, and on the 30th larvæ were found in
the stone water-reservoirs of the cook-rooms. Adult anopheles mosquitoes (A.
culicifacies) were first found in the barracks on June 16th. Throughout the
month, however, the number of adult insects in the barracks was very small. No.
A. Rossi were caught in the barracks during June. During July, rain-formed
breeding places were abundant in this section ; all the storm-water surface
drains especially formed good breeding grounds for A. Rossi. After each shower
of rain also, large areas of water collected in many parts of the lines, and a
number of deep trenches which had been made to mark off the boundary of the
cantonment grass-farm area, also became filled with water, which in two or
three days swarmed with larvæ. The shallow collections of surface water were
drained away into the irrigation canals. Collections of water in pools, drains or
trenches, were either emptied out or covered with a layer of oil.
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The number of adult insects found in the barracks increased quickly during
this month. On July 8th large numbers of A. Rossi were collected from the
barracks and harness rooms, and on the 11th these rooms also contained a fair
number of A. culicifacies.T h r o u g h o u t t h e m o n t h , h o w e v e r , t h e n u m b e r o f
adult anopheles mosquitoes present in the barracks and other parts of this section
was not nearly so great as in the parts of the cantonment where no operations
had been carried on.
The following is a list of the places where anopheles larvæ were found in
this section during August:
—
(1) Numerous waste water pools from stand-pipes, cook-houses, and wells.
(2) Small brick drains leading away from the above.
(3) Numerous rain-formed pools in the surface (storm-water) drains and
on the open plain.
(4) Tins of water kept near the barracks and hayricks in case of fire.
(5) The swimming baths.
These breeding places (except the swimming baths for which no method
could be devised), were dealt with regularly. During the month the number of
adult anopheles mosquitoes present in the barracks increased considerably.
The breeding places during September and October were similar to those
in August and had to be regularly dealt with ; the section being gone over weekly
for this purpose.
The number of adult insects to be found in the barracks was greatest
during these two months.
During November the number of adults and larvæ gradually diminished,
and by the end of the month no adults could be found and no fresh batches of
larvæ appeared in any of the breeding places.
IV.—The Stables Section.
This section is an extension of the previous one, and as it contained a
similar class of breeding places, it is unnecessary to record the operations regard-
ing it in detail. It should be mentioned, however, that during August anopheles
larvæ were found on several occasions in two wells in this area which were not often
used. The level of the water in these wells was about thirty feet from the surface.
V.—The Gardens Section.
The diary regarding this section is chiefly a record of numerous breeding
places formed in the gardens of the officers' houses as the result of irrigation
or of rain. From the commencement of the operations the surroundings of
each bungalow were carefully examined at least once a week and all breeding
places dealt with. Several of the officers themselves assisted in doing away
with all breeding places in their compounds. In spite, however, of constant
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attention to all breeding places, adult anopheles mosquitoes could always be
found in the bungalows and in the servants' quarters. In several of the
compounds as many as twenty pools containing anopheles larvæ would be found
at each examination, as well as small drains, iron cisterns, and the stone
water reservoirs which are present in the garden of every Indian bungalow, and
although all these breeding places were effectively dealt with at each examin-
ation, in less than a week they had nearly all re-formed and become again
swarming with larvæ. One of the most difficult breeding places to deal with
in this section was the waste water from the garden wells, which caused a
small marshy area to form round the well in which anopheles mosquitoes bred
freely. Wherever possible this water was drained or swept away, but in most
compounds frequent application of oil was all that could be done.
Other difficult breeding places to deal with in this section were the pools of
water round the road-side trees.
As these pools are replenished daily by a fresh supply of irrigation-water,
before they have completely dried up, they form favourable breeding places.
VI.—The Pools Section.
It is unnecessary to enter into detail regarding the numerous rain-formed
pools which had to be dealt with during the months of June, July, and August.
The following extract from my diary will, however, give some idea of the number
of pools formed by a rainfall of a few hours' duration on July 27th:
—
"On the 28th July as the result of two hours rain yesterday the following
pools which will remain sufficiently long for the development of larvæ were found
in the area:—
(1) 40 pools beyond the hospital.
(2) 12 ditches surrounding grass-land beyond the hospital.
(3) 24 pools about three feet deep, and three large ones about four or
five feet deep, beyond the syce lines.
(4) 21 smaller pools, which will probably dry up in three or four days
between the syce lines and the barracks.
(5) 6 very large pools and 8 smaller ones, at the rifle butts. (The large
pools are about 12 yards long by 10 yards wide and about four
feet deep.)
(6) 5 large pools, 3 smaller ones, and two ditches near the Persian wheel
of the fourth watercourse.
(7) 2 large pools near the east part of the fifth watercourse.
(8) 5 large shallow pools in the Royal Artillery Bazaar, 10 of the same
kind near the Right Battery stables, and 3 near the Left Battery
stables.
F
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(9) A group of large pools near the Police guard.
(10) 22 deep road-side pools behind the Royal Artillery Bazaar."
In addition to these, most of the surface drains were full of standing water
and innumerable small pools and broad collections of water covered the area on
every side. Rain fell again on the 1st and on the 3rd of August, so that even
the smaller pools had no opportunity of drying up for a week or more. Large
numbers of anopheles larvæ were found in all these pools, and even in the broad
shallow collections of water on the open plain, as early as two days after their
formation. As soon as a pool was found to contain larvæ it was covered with a
layer of kerosene oil, or dried out, and marked to be filled in with earth.
By the end of October over 250 of the larger sized pools had been filled in
with broken bricks and earth.
The above is a brief account of the operations against mosquitoes carried
out during the summer of 1902. The greater part of the work of filling in pools
and emptying out water from the surface drains was done by contract labour, so
as to avoid the necessity of constantly watching the coolies to see that they
were working properly, thus leaving myself and my hospital assistant more time
for searching for new breeding places. Work of this kind is also done much
more quickly and less expensively by putting it out on contract than by employ-
ing a large number of coolies on a stated daily wage. My object was as far as
possible to deal permanently with each breeding place as it was found, so as to
avoid having repeatedly to deal with the same breeding place. This, however,
can only be done with a limited number of permanent pools, and the chief diffi-
culty met with in Mian Mir arises from the fact that the bulk of the breeding
places require constant and regular attention throughout the summer.
I.—Operations during the winter of 1902 and the spring of 1903.
I have already mentioned that the number of larvæ to be found in all the
breeding places and the number of adult insects present in the houses gradually
decreased during November until by the end of the month I was not able to
find any adult insects in the houses and no new batches of anopheles eggs or larvæ
appeared in any of the breeding places. It was necessary to find out whether the
disappearance of adult anopheles mosquitoes was complete or whether a certain
number still remained in the houses in a "hybernating" condition throughout the
winter ready to lay their eggs when the warm weather came again in the spring.
During December and January I made experiments to test this point. In the
first place I allowed all favourable breeding places in the area to remain un-
touched during December. If any adult female anopheles mosquitoes were really
present in the houses, it was almost certain that some of them at least would
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occasionally come to the pools and lay their eggs as they had always done during
the summer, for the nights during December were not invariably cold. During
December, however, not a single anopheles egg or young larva was found in any
of the breeding places in the area of operations. This was strong evidence that
all adult anopheles mosquitoes had disappeared from the area. Further proof
was afforded by the following experiments. Having chosen a house in which
abundant adult anopheles mosquitoes had been constantly found during the sum-
mer, I covered the floor with sheets, and having carefully closed all the outlets,
four or five cones composed of a mixture of nitrate of potash, charcoal, sulphur,
and pyrethrum powder were burnt in the housefor two hours. During the sum-
mer I had proved that two of these cones burnt in a house of the same size
were sufficient to kill all the mosquitoes in it. In December, however, not a single
dead anopheles was found on the sheets spread on the ground. This experiment
was repeated in a number of houses, stables, sheds, arches of bridges, and other
places where it appeared probable adult anopheles mosquitoes might hybernate
through the winter. Numerous culex mosquitoes (which were very plentiful in
December and January, and regularly laid their eggs in the breeding places),
were killed by this method, but no anopheles. I conclude therefore that all
insects of the latter genus had disappeared from the area or died from the cold
by the beginning of December. It was necessary now to ascertain whether
this disappearance was a natural one or whether it was due to the operations.
Control observations were therefore made in a part of the cantonment where
no operations had been carried on and in a village (Shadara) about six miles
from Mian Mir where permanent breeding places of all kinds were abundant.
The results of these observations which were made in January and the
beginning of February were as follow:—
(1) No adult specimens of A. culicifacies or A. Rossi were found (even
by the method of burning cones) in parts of the cantonment where
no operations had been carried on, or in Shadara.
The result of these observations was therefore the same as that of the
observations within the area of operations.
(2) In recently formed pools at Shadara no larvæ of A. culicifacies or A.
Rossi were ever found, thus confirming the first observation.
In permanent breeding places which had remained from the summer
without drying up, larvæ of A. culicifacies could still be found
throughout the winter. These larvæ were in a more or less
"hybernating" condition ; their movements were sluggish and they
grew extremely slowly if at all. None were seen to develop into
pupæ and it seems probable that they cannot do so until the warm
weather comes.
Even in these old pools, however, no larvæ of A. Rossi were found.
F2
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(3) In Shadara a fair number of adult specimens of A. fuliginosus and a
few A. pulcherrimus were found in the houses throughout the
winter.
Both these species are at all times very rare in the Royal Artillery
lines and it is not surprising therefore that in the winter none
should be found there, though they were present in the village of
Shadara..
(4) Eggs, young larvæ and pupæ of A. fuliginosus and A. pulcherrimus
were found in new breeding places formed during the winter in
Shadara though no larvæ of A. culicifacies or A. Rossi were found in
these pools.
The only adult anopheles mosquitoes which were found in Shadara did
not, therefore, hybernate in any sense of the term, but carried on
their usual habit of laying eggs which developed into pupæ and adults
even in the coldest months of winter.
It is evident from the above observations that as regards the Punjab all
species do not tide over the winter by the same methods. A. fuliginosus and
A. pulcherrimus live through the winter continuing the same habits as in the
autumn. The adult insects of A. culicifaciesc o m p l e t e l y d i s a p p e a r o r d i e o f f
during the winter but some larvæ of this species remain alive in permanent breed-
ing places in a more or less "hybernating" condition until the warm weather
comes again. Both adults and laræ of A. Rossi disappear entirely from the
Punjab during the winter, and do not return again until the end of June or the
beginning of July, some time after A. culicifacies has already become fairly
prevalent.*
The observations appeared to show that A. culicifacies, the carrier of
malaria in Mian Mir, is able to tide over the Punjab winter solely by means of
"hybernating" larvæ, and it was therefore my object during the winter months
to kill off all such larvæ within a wide distance of the area.
As no new batches of eggs were being laid in the breeding places this was
not a very difficult task. Daily expeditions were made in every direction from
the centre of the lines, so that the ground was covered in ever widening circles
and no pool or collection of water of any kind was left unoperated upon. At the
same time the experiments of burning pyrethrum cones or neem leaves in the
houses of the area were continued, as I wished to leave no margin for errors of
observation in the previous experiments. For a number of these experiments
I used dried neem leaves instead of pyrethrum cones as it was difficult to obtain
a sufficient supply of the latter. During the summer I had found that neem leaves
* The observations concerning the complete disappearance of adult specimens of A. culicifacies and
A. Rossi and the persistence of adults of A. fuliginosus (in the form of an interesting "winter variety") have
been confirmed by Major Adie, I.M.S., at Ferozepore.
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which they are very abundant. Such a gradual invasion of a new area results
from the fact that all newly hatched mosquitoes do not return to the house
or village from which their parent came, but fly to houses in the opposite direc-
tion; and having found their food there, proceed to breeding pools still further
removed from the original village. A gradual invasion of the Royal Artillery lines
by adult A. culicifacies occurred in this manner from surrounding villages where
no operations had been carried on, but which were connected with the lines by
isolated houses and breeding places.
There is still a fourth method by which anopheles mosquitoes reach the area
from outside, viz., by being conveyed in carriages, carts, and other vehicles from
neighbouring towns and villages. This method was one of daily observation in
our work during 1901 and 1902.
When all these methods are taken into consideration, it is not surprising
that in spite of the vigorous operations during the winter, anopheles mosquitoes
(A. culicifacies) were again almost as prevalent in the area at the end of May
as they had been at the beginning of the previous year's work. As in the previous
year, however, no A. Rossi or its larvæ had been found in the area or in surround-
ing villages up to this time, and if the seasonal prevalence of this species during
the present year is similar to that of last year they cannot be expected until the
end of June or the beginning of July.
It will be apparent from the results just recorded that the destruction of
anopheles mosquitoes in Mian Mir is a task which must be repeated every year.
II.—The removal of a number of people to a distance from all
breeding places of mosquitoes.
It was not our original intention in Mian Mir to test the value of any
method of getting rid of malaria except that of the destruction of anopheles mos-
quitoes, but when I found that this might be a task of great difficulty, I thought
it advisable to make an experiment which would, if successful, conclusively
prove that if the presence of anopheles mosquitoes in a place can be entirely
eliminated, malaria will quickly disappear.
As we had already shown that the further a group of houses is removed
from a breeding place the fewer are the adult insects present, my plan was to
remove all the inhabitants of one series of syce lines to such a distance from
all breeding places that no anopheles mosquitoes at all should be present in the
houses on the new site. In Mian Mir the dry open plain extends for several
miles in some directions, and it was not difficult therefore to find a site suffi-
ciently far removed from all irrigation canals and pools. The people chosen for
the experiment were the inhabitants of the first series of syce lines (plan of R. A.
lines, A).
These syce lines were situated within 140 yards of an irrigation watercourse
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and contained about 78 children, 56 per cent. of whom had malaria parasites in
their blood in October 1901. In August 1902 I caused all the inhabitants
(men, women, and children) of this series of syce lines to be moved into tents
on a site ¾ of a mile from the nearest irrigation watercourse and over 600 yards
from the nearest pool. As a result of this no adult anopheles mosquitoes were
found in any of the tents during September and October of the year of operations.
In every other respect, however, these people were under precisely the same
conditions on the new site as they had been on the old, except that, being in tents,
they were more exposed to the sun and rain than they had been in their houses
on the old site. The result of this experiment is given in Part III (page 44).
This experiment also afforded an opportunity of testing to a certain extent
the practicability of the method of “segregation of Europeans ” recommended
by Stephens and Christophers in Africa, in that by the removal of this large source
of infection of anopheles mosquitoes, one of the chief dangers to the men in
barracks was effectually done away with.
III.—Operations directed against malaria parasites in infected
individuals.
In addition to the experiment described above, I thought it advisable to test
the practicability of a modification of Professor Koch's method of getting rid of
malaria by the systematic treatment of all infected people with quinine.
I have already mentioned that the native children in the different followers'
lines and in the Royal Artillery Bazaar form the chief source from which
anopheles mosquitoes become infected. It was desirable therefore as far as
possible to do away with the effect of these large sources of mosquito infection.
With regard to the first dangerous source of infection (the first series of syce
lines) this had already been done by their removal to a distance. The other
method by which the same result might possibly be attained was by the
systematic treatment of all children with quinine ; and on account of the
expense and inconvenience which would arise from the permanent removal of
the syce lines to a distance of half a mile or more from the barracks, it was
very important to ascertain whether the plan of the systematic treatment of
children was a practicable and effective one.
The second dangerous source of infection of anopheles mosquitoes was
afforded by the children in the hospital followers' quarters, which are situated at
the back of the hospital compound about 40 yards from the hospital and the
prison and about 400 yards from the main barracks of the troops. It was found
impracticable to have the hospital followers and their families moved into new
quarters at a distance from the hospital, and I decided therefore to treat all the
children regularly with quinine. They numbered 34 in all. The treatment was
commenced on August 30th and each child received a dose of from five to ten