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There is nothing to make us believe that deltaic or other physical
conditions are necessary for the occurrence of epidemic malaria, for
anopheles mosquitoes exist throughout the country and can every-
where find facilities for continuous breeding; and such being the case
we have reason to anticipate that, with each fresh impetus and new
direction given to industrial expansion, we shall find, in the absence
of proper measures of control, an extension in the geographical dis-
tribution of intense malaria and hear of new areas subject to the ravages
of the disease in epidemic form.
It may be said that these unfortunate influences, the action and
result of which we have indicated in broad outline, are in themselves
so vast that they lie beyond the power and scope of human
interference and that their recognition will not help us in the
war against disease. But although we may not be able to deal with
the malaria of a whole province, with a population numbering many
millions, many of whom are probably but little affected by the disease,
we can deal with malaria among the labourers on a railway, a canal,
a coal mine, or a tea garden, in a way that we cannot do with malaria
among the more widely scattered populations of great rural areas;
and by this means we can prevent the occurrence of, or reduce the lia-
bility to, the otherwise inevitable scourge of intensified epidemic
malaria, and attain a result that will prove out of all proportion greater
than the mere direct effect upon those immediately concerned for
beyond the loss of life and suffering of the actual labourers is the all-
important question of the health of large communities which they are
liable to infect.
With the methods to be adopted in malarial prophylaxis we
do not here concern ourselves; but if we are dealing with an exalta-
tion of malaria due to the action of factors affecting the human host,
where every influence that tends to increase susceptibility is at its
height, there are other measures required besides those of specific
prophylaxis, measures which, while they incidentally aim at relieving
hardship and misery, are directed at a vulnerable point in the de-
velopment of the most important of all topical diseases.
We cannot ignore  such  assistance, as we have not yet any
reason to believe that anti-larval operations are capable in the least