Report of the malaria expedition to the Gambia 1902, of the Liverpool School of Tropical Medicine and Medical Parasitology / by J. Everett Dutton ; and an appendix by F.V. Theobald.

  • Dutton, J. Everett (Joseph Everett), 1876-1905.
Date:
1903
Catalogue details

Licence: In copyright

Credit: Report of the malaria expedition to the Gambia 1902, of the Liverpool School of Tropical Medicine and Medical Parasitology / by J. Everett Dutton ; and an appendix by F.V. Theobald. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    suitable for the development of mosquito larvae, which were present here in fair numbers, chiefly larvae of Anopheles costalis. This condition obtained, when I arrived in Bathurst, and lasted through the months of October and November, that is, until the level of the ground water had sunk below the bed of the drain. The streets in which these conditions occurred are Dobson Street, Hagan Street, Blucher Street, Hill Street, part of Lemon and Buckle Streets. The other kind of drain occurring in Bathurst is that which has been described as a trench dug along the centre of the streets. These drains either communicate with the big drains or discharge directly into the swamps. It was pointed out that the depth of these drains vary, and that they often are converted into a series of pools by rubbish and sand either thrown into them or by natives walking across. I found these drains to be almost universally infested with mosquito larvae, which occurred in great quantities along their course, and were for the most part all of the genus Anopheles ; only very occasionally did I find the Culex type of larvae in any amount. The small fish, which have been mentioned as being so beneficial in keeping the larger-made drains free from mosquito larvae, though occurring also in many of the grass-choked drains, are here at a disadvantage, the larvae being to a great extent pro- tected by the grass and sticks amongst which they can hide ; also pools cut ofF trom the main masses of water occur in which fish cannot gain entrance. These drains supply Bathurst with the majority of its mosquitoes during the months of September, October, and November. They occur in the following streets : Fitzgerald Street, the drain runs along the centre of this street from the corner of Kent Street to Box Bar, where it is supposed to empty itself by a channel running down Lovel Place, entering the main drain leading into a swamp. The uselessness of these stretches as a whole are well illustrated by this drain, where I found the outlet completely blocked up with sand and rubbish, so that water would of necessity flow over Lovel Street to get into the swamp, and small fish for this reason also could not possibly gain entrance. Further, the drain itself had been converted into a series of long pools by the natives walk- ing across, carrying with them sand, etc., and, lastly, the thick, rank grass growing in the bed of the drain, together with its naturally small fall, tends to retain the water in it. This drain is bricked across by two or three low, brick arches at the street crossings. Underneath these arches the bed of the drain dips, so that water collects in considerable quantity,