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act most intensely among the poorer and more ignorant classes. But in the
malarious parts of Bombay although those of low social status such as sweepers
and others suffer greatly from malaria, those of the better social standing are
by no means exempt from the disease. In particular the Pársis (as has already
been pointed out) who as a community are comparatively well off, are better
educated and possess a higher standard of living than many other classes in
Bombay, often show greater evidence of malaria. This is especially the case
among those who reside in the North Port and Dhobi Talao. In these two
localities Pársis are probably more exposed to malarial infection than the other
classes of the community by reason of the open anopheles-infested wells that
are to be found inside many Pársi dwelling-houses.
224. In other parts of the City, especially in portions of the Fort and
Colaba, Europeans and Indians of good social standing often contract malaria.
One reason for this is the wide distribution of breeding places of the malaria
carrier, but another cause is the fact that in almost all the modern flats which
are largely used as places of residence by Europeans and better class Indians,
quarters for native servants are constructed under the same roof. It frequently
happens that in these quarters, which are often very small and cramped, a low-
class native population is harboured as great or even much greater in number
than their employers. Among these people malarial infection often exists to a
considerable extent and it follows that, should N. stephensi be breeding in.
the house cisterus or in the neighbourhood and adult insects gain access to
the houses, all the factors necessary for the spread of malaria are present. This
partly explains the frequent occurrence of malaria among people of good social
standing in Bombay.
225. Overcrowding in relation to Malaria in Bombay —In the foregoing
paragraph one effect of overcrowding has been noticed, but there is an even
more important one to be considered. It has frequently been stated that
malaria tends to diminish in proportion as the density of a population increases.
The explanation is to be sought in the comparative absence of breeding places
of ordinary carriers of malaria usually met with in centres of dense population.
But in Bombay many areas which possess populations of more than 200—400
people per acre are most malarious. This is explained by the domestic habits
of Neocellia stephensi and the peculiar character of the breeding places selected
by it. Provided the carrier of malaria is present, density of population tends
to increase rather than diminish the intensity of infection, for anopheles have
no difficulty in obtaining food and shelter in the crowded dwellings, and an
infected insect has far greater chances of biting large numbers of different
people in a short time when from five to twenty are sleeping in a single room,
than in places where the population is comparatively sparse. Overcrowding in
Bombay also leads to many thousands of people sleeping out-of-doors and
these persons are specially exposed to the attacks of mosquitoes. In parts of
the Port near the New Docks hundreds of people may be seen almost all the
year round sleeping out-of-doors ; and a large proportion of these people are
infected with malaria.
226. The effect of Economic conditions on malaria in Bombay.—In one
of the earlier paragraphs of this report attention was drawn to the economic
conditions of the population and in another paragraph in discussing epidemic
malaria reference was made to the sudden rise of prices in Bombay during 1907
and 1908. The importance of economic conditions in modifying malaria has
only recently been recognized although it has long been known that the disease
tended to diminish in times of great prosperity and to increase in times of
scarcity. Christophers* as the result of investigations carried out in the Punjab
has shown that the occurrence of epidemic malaria there is often closely
associated with two factors, abnormally heavy rainfall and high prices of food.
When these two conditions are present at the same time, as in 1908, epidemics
occur, but neither heavy rainfall nor high prices produce the same result when
acting alone. The occurrence of heavy rainfall in the Punjab always results in
an increase in the number of malaria-carrying anopheles, but in Bombay, as has
been pointed ont in another paragraph, the amount of rainfall does not appear
* Vide " Paludism " No. 2, February 1911.
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