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Lucknow and Jhansi are already extensively provided with permanent drain
age, in others where pukka drainage is lacking it is a moot point whether such
drainage really has any bearing on the incidence of malaria.
(ii)
Mosquito destruction in occupied premises is of paramount importance
and for this the development of spraying with insecticide is proving of the
greatest value. In many places it is the method of choice and the only practi
cable method. The method has the great advantage that it deals with mos
-quitoes, sandflies, flies, fleas and bugs, and that it can be applied to existence
in barracks, camps, quarters or in the field.
(iii)
Personal protection is the final main standby. Protection with the
mosquito net is held by some eminent malariologists to be capable of prevent
-ing 95 per cent. of all infections. Unfortunately there are times when the
standard pattern net cannot be used or even any net at all and in addition we
have not yet succeeded in providing net protection for Followers who form a
large part of our military population.
Every possible method is utilised in some station or other during the year;
but in this report only those which have been specially in evidence during this
year will be mentioned. But in assessing the value of any particular method
factors such as the following have to be borne in mind.
A spleen census of school children carried out by the Health Department
of the Punjab since 1914 shows that for the past 3 years malaria in that area
has been abnormally low and that any decrease in cases in a cantonment is
not necessarily due to the excellence of the anti-malarial work.
(a) Elimination of the "carrier" mosquito
(i) Anti-larval methods and prevention of breeding. Permanent works and
drainage .—These have been continued as funds were available. The budget
demand for these from all districts is still very large indicating how much
remains to be done. Rs. 61,379 out of a budget item of Rs. 75,000 were allott
-ed for this purpose during the year. Closure of unused wells and pukka drains
for large nullahs have been a feature of the work. In many places properly
constructed grassed banks with a central pukka channel is the method of choice.
Oiling of breeding places.—This has been continued, Malariol being given
a full trial. The reports were satisfactory and Malariol will for 1940 replace
the previous oil mixture.
Prominence has been given to the effectiveness of dealing with breeding
places by spraying with pyrethrum spray solutions. Killing of larvæ is
obtained in a few seconds over wider areas than can be done by oiling. The
method is being progressively extended.
The "dry-day ".—This method is proving most useful in two ways;
firstly that all potential sources of breeding in the cantonment are dealt with
and secondly the "dry-day" tends to make all personnel in the cantonment
anti-malaria-conscious.
The mosquito culprit.— Attention has been given to the mosquito actually
concerned in the infection in the locality. A. culicifacies and A. stephensi
share the honours in most areas, but interesting observations have been
obtained in the Kohat and Quetta areas on the effect of the temperatures
of the air and of the spring and irrigation waters in the preponderance of
one species or another, A. culicifacies preferring higher temperatures than
A. stephensi.
" Sluicing" drains.—This method has been developed for slow flowing
drains at Abbottabad, Jhelum and Peshawar with excellent effect. It is an
inexpensive method which shows good results.