86
to generally influence the anopheline factor. But when from any cause the
number of malaria-carrying mosquitoes in Bombay is increased the occurrence of
a coincident rise in the prices of the necessaries of life would reproduce on a
small scale the conditions shown by Christophers to lead to severe epidemic
malaria in the Punjab.
As we have already seen prices of food and fuel rose to an abnormal
height in Bombay during latter part of 1907 and again in 1908. This rise
occurred at the malarious season of the year and if we assume that the carrier of
malaria was specially abundant in 1908 the coincidence of these conditions
would explain the severe outbreak of malaria in that year.
227. This is not the first occasion in which high prices appear to have
influenced the occurrence of outbreaks of malaria in Bombay. In 1757 at the
time when an outbreak of disease, probably malarial in nature, occurred among
the labourers employed upon the fortifications, and affected the general
population, prices of food were so high, that the workmen petitioned the
authorities to supply them with grain from the Company's stores ; and a little
later, the shoe-makers who supplied the troops appealed to be allowed to increase
their charges on the grounds that rents had gone up from Re. 1 and Rs. 1-8 to
Es. 3 and grain from Rs. 1-4 to Rs. 2-8 a maund.
228. The effect of sudden rises of prices upon a considerable proportion of
the poorer households in Bombay has been traced in the introductory chapter ;
but the influence which it may exert in increasing malaria among an already
infected population will be better understood when it is pointed out that
among troops and bodies of labourers infected with malaria observation has
shown that abstinence from food, prolonged only a few hours beyond ordinary
meal-times, is sufficient to bring about many relapses of malaria a few days
afterwards. And an epidemic of relapses in places, where the carrier of the
disease is present, is the precursor of an abnormal number of new infections. A
rise of prices in Bombay always means increased economic pressure among the
poorer classes, which leads to privation and a consequent dimination of their
powers of resistance to disease ; and in parts of the City where malarial infection
is present and a sufficient number of the carriers of the disease exist a vicious
cycle is thus set up, privation leading to relapses, and relapses causing an increase
of new infections, and so on, until an epidemic of malaria is produced.
229. Soil disturbance and outbreaks of Malaria.—For many years it has
been recognized that outbreaks of malaria frequently occurred in association
with excavation and other works involving soil disturbance ; and these observa-
tions led to the old theory that the virus of malaria was present in the soil and
that over-turning the soil allowed it to escape and diffuse into the atmosphere
with the result that epidemic outbreaks occurred. Unfortunately many people
still cling to this idea and it is necessary on this account to try and make clear
the sequence of events which leads to outbreaks of malaria often more or less
directly associated with construction works in the tropics.
230. In the East the coolie labourers employed on such works are drawn
almost entirely from the poorest and most ignorant classes of the population ;
they are often brought long distances and set down in a country where the
climate, and even the food obtainable, differ greatly from that to which they
are accustomed. If housed at all they are generally crowded into temporary
huts, but frequently they are left to find what shelter they can. Often they
have no one to look after them when sick and no means of obtaining food when
for any reason they are unable to work. Their work is arduous and their pay
small ; and as they generally try to save money for the support of dependents
at home it is no uncommon thing to find them attempting to exist upon a
miserably insufficient diet. Camped, as they usually are, upon the site of the
work, their surroundings are almost always highly insanitary, for there is rarely
any pretence at a conservancy system and sometimes no proper water-supply ;
and if much earth work is going on, the numerous pools of water formed during
the rainy season speedily become the breeding places of countless swarms of
mosquitoes. In these circumstances it is not surprising that coolie labourers
ou large public works should be decimated by outbreaks of epidemic disease,
tending to increase in severity as the work progresses. But whatever happens