Fevers in the tropics: their clinical and microscopical differentiation, including the Milroy Lectures on Kala-azar / by Leonard Rogers.

  • Rogers, Leonard, 1868-1962.
Date:
1908
Catalogue details

Licence: In copyright

Credit: Fevers in the tropics: their clinical and microscopical differentiation, including the Milroy Lectures on Kala-azar / by Leonard Rogers. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    MICROSCOPICAL EXAMINATION OF THE BLOOD, LYMPH AND CEREBRO-SPINAL FLUID THE BLOOD CHANGES, PRESENCE OF THE TRYPANOSOME.—As an account of the extremely uncharacteristic nature of the early stages of trypanoso- miasis shows it to be impossible to diagnose the disease, with certainty, by purely clinical measures, the microscopical examination of the blood and tissues in which the trypanosome is to be found is of the greatest practical importance. Although the organism was first found in the peripheral blood, yet it may often be absent from it for considerable periods, and be very scanty and easily overlooked when it is present there. For this reason the examination of a small drop of fresh blood under a cover-glass with an | inch lens (which will allow of the active movement produced among the red corpuscles by the parasite being detected), although a method efficient, when numerous organisms are present, often fails when they are very few. A much better way is to withdraw several cubic centimetres of blood from a vein, into a little citrate of soda solution, or several large drops from the finger tip and centrifuge it in a small tube, the distal end of which has been drawn out into a narrower portion. Dutton and Todd advise slow centrifuging first for several minutes, and then for a shorter time at a higher speed. The thin layer of white corpuscles on top of the red should be pipetted off and examined fresh for the motile organisms, the whole procedure being completed as quickly as possible, on account of their rapid loss of motion outside the body. By this means the parasite can be frequently found in the blood when a simple microscopical examin- ation fails to reveal it. The improved centrifuging method, however, has been to a large extent superseded by the simpler and still more efficacious mode of gland puncture to be described below. The microscopical appearance of the organism is shown in Plate 8. A drawing of the carrier of the infection, the tsetse fly, is also given. THE RED CORPUSCLES AND HAEMOGLOBIN have been carefully studied by Greig and Gray, who found them to be normal, in the early stages of sleeping sickness, while towards the end both might be actually increased without any signs of cyanosis. THE LEUCOCYTES show marked changes, consisting of an increase of the mononuclears at the expense of the polynuclears, as in some other protozoal infec- tions, while the total count is usually either within the normal limits, or shows a slight degree of leucocytosis. Table VII has been worked out from a number of counts of Greig and Gray, while Dutton, Todd and Christy, in the Congo State obtained very closely similar results.