58 Eosinophilia in Bilharzia Disease and Dracontiasis1 Previous observations Methods of staining, counting, and \ classification X \ ) In the Lancet of October 10th, 1903, p. 1009, there is an article by Captain S. R. Douglas, and Major F. W. Hardy, R.A.M.C., on 50 cases of Bilharzia Disease, in which they gave an account of the results obtained by them in the differential leucocyte counts. Their very complete and interesting investigation was apparently instigated by Coles’s observations 2 on one case of bilharzia disease, in which he found an increase of coarse-grained eosinophile leucocytes. His case was that of a young Englishman in whose blood he discovered 20 per cent, of these cells instead of the normal 2 to 4 per cent. Hayem puts the normal at 7 per cent. With a view to confirming Coles’s solitary observation I proceeded in my spare time to examine the blood of the few bilharzia cases I could obtain in Khartoum and Omdurman. Bilharzia disease, so far as is known, is not common in the Egyptian Sudan, save amongst those who have acquired the infection in Egypt or elsewhere, and owing to this and other reasons I was only able to examine three cases. At the same time I thought it well to investigate the blood condition in dracontiasis. At the time I began to do so I believe no work had been accomplished on this subject, but while I was thus employed a paper3 appeared by Dudgeon and Child recording their results in one case of guinea-worm disease in an Englishman infected in India and resident in London. They found from 13*0 to 18*4 per cent, of coarse-grained eosinophiles present, and suggest that in this respect dracontiasis may occupy a position midway between trichiniasis and infections with other internal parasites. I have notes on six cases of guinea-worm disease, and had intended collecting further statistics before publishing an account of them, but as I find my results confirm theirs in large measure I think it well to place them on record, especially as some time must needs elapse before I can add materially to my number of cases.

Method.—In each instance I counted 500 leucocytes, and in nearly every case made a double examination, one film being stained by Jenner’s method and the other by the Leishman-Romanowsky. The counts were found to approximate very closely, and that obtained in the better-stained film was taken as correct. In several instances also other confirmatory counts were made. In differentiating large mononuclears from lymphocytes I followed the plan adopted by Captain Leonard Rogers and classed every single unlobed nucleated corpuscle as large as, or larger than, a polymorphonuclear as a large mononuclear. Like Captain Delany, I preferred to place transitional forms under the heading polymorphonuclears, but I see that Dudgeon and Child counted them as lymphocytes.

1 This paper originally appeared in the Lancet, 12/12/03. I am indebted to the Editor for kind permission to re-publish it here 2 Diseases of the Blood, Coles.

3 Eosinophilia associated with Dracontiasis.—Journal of Tropical Medicine. 15/8/03