3
the chief carriers of malaria are believed to be stream-breeding mosquitoes
which differ in their habits from the common carriers of malaria met with
in deltaic areas. The two schemes have been specially drawn up with the
object of ascertaining the best method of dealing with these mosquitoes
and determining the minimum area round a village that must be controlled
in order to bring about a reduction of malaria.
At Meenglass the hill streams, in which a dangerous species of anopheline
mosquito breeds, will be put underground, the water being carried off in
subsoil drains when the flow becomes sluggish, while the storm flow is
allowed to pass over them in the usual stream channels. The Singaram
scheme consists of two parts, viz., (1) a thorough surface drainage of the area
to be experimented on, and (2) the periodical flushing of a small river in
which malaria-carrying mosquitoes of a vicious character breed. The object
of the first part is to drain away pools and depressions in which malaria-
carrying mosquitoes breed: that of the second is to substitute a series
of flushes in the river instead of a sluggish flow, for it has been ascertained
that mosquitoes breed along its edge when the flow is gentle, but when the
river is in flood their eggs and larvae are carried away. It is therefore pro¬
posed to construct a weir with sluices so arranged that, when the sluices are
closed. a head of water will be accumulated behind the weir, and this will
be periodically discharged so as to flush the bed of the rivulet.
It is
hoped that three of the schemes will be completed during the current
year ; and the Governor in Council looks forward to the results of the experi-
ments with much interest.
8. Stegomyia Enquiry.—A conference was convened by Government in
November 1916 to consider the measures necessary to establish homogeneous
sanitary control throughout the port of Calcutta, with special reference to the
question of taking measures to prevent the introduction of yellow fever
through the medium of the stegomyia mosquito in consequence of the
opening of the Panama Canal.
9. Cholera.—Owing to the absence of virulent epidemics, which is
attributed to copious and seasonable rainfall, the number of deaths from
cholera fell from 130,679, which is the highest figure as yet recorded in the
Presidency, to 70,836, which is the minimum on record. Steps were taken by
District Boards to cope with cholera outbreaks by the disinfection of wells
and the appointment of itinerant doctors ; but the Sanitary Commissioner is
of opinion that much cannot be expected till all the District Boards possess a
proper sanitary organization.
The question of the reorganization of the
sanitary staff employed by these bodies is now under consideration.
10. Small-pox.—It is satisfactory to find that the steady rise in
mortality from small-pox, which culminated in 32,785 deaths in 1915, has been
checked, the number of deaths reported in 1916 falling to 13,890. The
highest district death-rate was returned by Bankura, viz., 1.32 per mille.
The Civil Surgeon attributes the outbreak in that district to the fact that
most of the sources of water-supply in the villages had dried up owing to
the failure of the rains in the preceding year. Calcutta, which suffered
from a virulent outbreak of the disease in 1915. was almost immune, only
58 deaths being returned.
11. Vaccination,—The total number of persons returned as having been
vaccinated during the year 1916-17 was 1,598,428 as against 1,635,621 during
the previous year. The decrease is said to be due chiefly to the stricter
supervision exercised by inspectors and sub-inspectors of vaccination over the
work of the vaccinators and by Deputy Sanitary Commissioners over the
work of both, the effect being to check the temptation to submit false figures.
Free vaccination at the cost of the District Boards was introduced as an
experimental measure in one thana of the Faridpur district, and was continued
with satisfactory results in the 24-Parganas and the Sadar subdivision of
Bakarganj. A large number of persons were operated on who had not been
vaccinated before and vaccination was introduced in villages which had
hitherto objected to it. In the towns 642 per mille of the surviving infant
population was reported to be protected ; but the Sanitary Commissioner