Review of some of the recent advances in tropical medicine, hygiene and veterinary science, with special reference to their possible bearing on medical, sanitary and veterinary work in the Anglo-Egyptian Sudan : being a supplement to the Third Report of the Wellcome Research Laboratories at the Gordon Memorial College Khartoum / by Andrew Balfour and R. G. Archibald.

  • Balfour, Andrew.
Date:
1908
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Licence: Attribution 4.0 International (CC BY 4.0)

Credit: Review of some of the recent advances in tropical medicine, hygiene and veterinary science, with special reference to their possible bearing on medical, sanitary and veterinary work in the Anglo-Egyptian Sudan : being a supplement to the Third Report of the Wellcome Research Laboratories at the Gordon Memorial College Khartoum / by Andrew Balfour and R. G. Archibald. 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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    Filariasis— Personally I cannot say much about filariasis in the Sudan. The only filaria I have continued found in human blood in this country was F. perstaus, and that in a Ugandese at Taufikia. In the only case of elephantiasis whose blood I examined at night I failed to find embryos. Neither have I found them in the blood of monkeys (GercopWiecus). Elephantiasis does occur, but is apparently not a common disease. Singer^ records that in South-Western Abyssinia elephantiasis occurs, but is rare. Ensor has recently reported filariasis to be common in the southern Bahr-El-Ghazal Province of the Sudan. Gulex fatigans is common all over the Northern Sudan and occurs also in large numbers on the Upper White Nile, but in these southern territories Mansonia imiformis is more likely to play the part of a filaria vector. A great deal of useful information could be obtained by the systematic examination of bloods at night in the various hospitals. So far as I know nothing has been done in this direction. It would entail hard work in such a trying climate, but during the winter months the examinations could be made without very much discomfort or fatigue. It would seem advisable, in the case of elephantiasis patients brought in for operation, to enforce the use of a mosquito net at night, as where G. fatigans or M. imiformis are present the disease might be transferred from the sick to the healthy. The question of infection with Filaria medinensis is considered under the heading Guinea Worm (page 83j. Filters. An important practical paper of recent date is that by Bulloch, Craw and Atkin-^ on the relative eflicacy of the Doulton, Berkefeld and Brownlow filters. An investigation such as they conducted was urgently required, for doubt had been thrown on the eflicacy of the Berkefeld filter, despite the statements of Woodhead and Cartwright Wood. The later investigators conclude that— Of all the filters tested, the Doulton filters alone uniformly prevented the direct transmission of micro- organisms ; the Berkefeld filters all permitted direct transmission, with one exception, and all the Slack and Brownlow filters gave contaminated filtrates immediately. In the case of the Berkefeld filters and the Slack and Brownlow filters the germs passed through within 15 minutes from the commencement of filtration, whereas seven out of ten Doulton filters withheld the organisms and gave sterile filtrates for four days and in three cases for longer periods. As these tests were made with a water pressure varying from zero to 32'5 lb. per square inch, often in a few seconds, the above examination appears to us to be not only severe but also conclusive. Craw has a supplementary paper on the grain of filters and the growth of bacteria through them, and brings out some interesting points. He finds that the size of pore is very small in the Doulton filter, relatively greater in the Pasteur-Chamberland, very much greater in the Berkefeld, and in the case of the Slack and Brownlow filter the pores are of striking magnitude. These points are very well brought out in a series of photographs. He concludes that the grain of a filter is a very important, if not the most important, factor in governing the growth of bacteria through the filter mass, and that in the filtration of fluids containing colloidal substances, suspended matter or micro-organisms, the chemical nature of the filter mass will be eliminated very rapidly as a factor in the efficiency of the filter owing to the formation of a coating of foreign material, derived from the fluid, over the chemically active surface. As regards water filtration on a large scale, much valuable information will be found in Hazen's work,^ which is far too little known on the eastern side of the Atlantic. A short resume of the subject, comparing the English sand filter with the American mechanical filter, is given by Eobinson.-^ As he points out, the latter, where a chemical precipitant is employed, are specially applicable to very turbid and muddy waters. The efficiency of the mechanical filters depends entirely on the use of coagulants, hence the value of a paper by Whipple and Longley ' on the necessity of using basic and not neutral alum in mechanical filtration. With neutral alum the bacterial efficiency was only 95-5 per cent., while with basic alum 98-4 per cent, was obtained. As a result they contend that specifications for filter alum should always require that there shall be a substantial excess of alumina, that is, ' Singer, C. (January 16th, 1905), Notes on Cases met with in South-Western Abyssinia in March, 1904. Journal of Tropical Medicine, p. 17, Vol. VIII. 2 Bulloch, W., Craw, J. A., and Atkin, E. G. (.lanuary, 1908), On the Relative Efficacy of the Doulton, Berkefeld and Brownlow Filters. Jowrnal of Eygicne, p. 63, Vol. VIII. Hazen, Allen, The Filtration of Public Water Supplies. New York, 1903. * Robinson, W. J. (September 15th, 1906), Artificial Purification of Water Supplies. British Medical Journal, p. 623, Vol. II. ^ Whipple, G. C, and Longley, F. F. (February, 1906), Experience with the Use of a Non-basic Alum in Connection with Mechanical Filtration. Journal of Infectious Diseases, Suppl., p. 166, Vol. III.