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Anopheline surveys were made at Stanley, Repulse Bay and Sookumpoo and reports submitted to Government.
The relative importance of the different varieties of water collections in the propagation of malaria carrying anophelines has not been fully worked out. This is a very important matter for on its solution depends, to a great extent, the economics of preventive measures. It is hoped in the coming year to establish a class of instruction under the Malarialogist and to tackle the mosquito problem in a scientific manner.
One thing is certain and that is that the nullahs with their inverts strewn with granite rocks and boulders and with tiny pools, seepages and small streams are typical breeding grounds for the dangerous malaria carriers A. maculatus and A. minimus. The draining of these nullahs so as to obviate all danger of breeding is a matter which is at the same time difficult and expensive. Every year the Public Works Department insert a sum in the estimates for "the training of Nullahs" and every year work up to the limit of the sum sanctioned is carried out. There can be no doubt that the disappearance of malaria from the populated area is in a large measure the result of the drainage works carried out by this Department.
Preventive Measures against Plague.
In the campaign against plague the routine measures which have been in vogue since the disease was at its height were continued. These were-
(a) periodical cleansing of premises-lime washing.
(b) abolition of rat refuges-such as ceilings, stair linings and panellings.
(c) destruction of rats.
In the crowded areas the periodical cleansing of premises is a most important factor in the prevention of the spread of disease. Every house is dealt with in its turn at least once a year. All the furniture is removed from the rooms or cubicles and all floors and woodwork washed down with an emulsion of soap and kerosene oil. This is done either by the sanitary staff or by the occupiers under the general supervision of the district inspector. Altogether 152,762 floors were dealt with.
Twenty-eight members of the cleansing staff were employed in setting traps, bird-liming boards, distributing barium-carbonate baits, and collecting rodents which have been taken living or dead. By far the greatest number of rats were taken dead from the many rat reception bins or tins which have been placed in convenient situations throughout the city. The Chinese object to rats being found in their premises by the sanitary staff and