In this monograph I have endeavoured to give a resume of the present state of our knowledge of Bilharziosis; and, in doing so, have naturally had to draw largely upon the work and experience of others in the same field. To these observers I wish here, at the outset, freely and frankly to acknowledge my great indebtedness.
I am especially beholden to my friend and colleague, Professor Looss, who has taken infinite pains in providing me with an abstract of that portion of his article in Mense's "Handbuch der Tropenkrankheiten" which deals with the life-history and mode of infection of the Bilharzia worm.
Again, much of the pathological description of the disease is the result of a study of specimens in the Pathological Museum of the School of Medicine in Cairo, prepared by Professor W. St. Clair Symmers, formerly Professor of Pathology in this School, now Musgrave Professor of Pathology in Queen's College, Belfast. For his kindness in revising an earlier manuscript of mine on the subject and allowing nie to avail myself so fully of the material at his disposal, I am deeply grateful; but I must accept all responsibility for any inaccuracies that may appear in the text.
In the clinical paragraphs I have included much of the work published by my former colleague, Mr. Frank Milton, in various papers, in my endeavour to make this side of the picture as complete as possible; and, throughout the whole monograph, I have avoided the discussion of controversial points, upon which much work is still to be done, and have tried to approach the subject from the standpoint of a practical surgeon.
I am also indebted to Dr. H. P. Keatinge, the Director of the School, for his ready assent to the publication of photographs of specimens and cases from the School collections; and, finally, to my friend and colleague, Professor A. R. Ferguson, the present Professor of Pathology in the School of Medicine, for so carefully revising with me the whole manuscript, I take this opportunity of expressing my sincerest thanks.
The pathological conditions included in the term bilharziosis are produced by the presence of the bilharzia worm, Schistosomum hœmatobium, in the human body.
Geographical distribution.—The bilharzia worm is endemic in Egypt, and also, to a more limited extent, in South Africa. Endemic centres appear to exist in Syria, the Soudan and Uganda, Madagascar, Mauritius, Reunion, China, Cyprus, and the West Indies; and sporadic cases of bilharziosis, probably contracted in one or other of these centres, have been reported in many other countries, for instance, in England and Australia, among the troops who have recently returned from South Africa.
Description and life-history.—The worm belongs to the group of the Trematodes, but is distinguished from the majority of this group by having male and female separate individuals.
The male worm, to the naked eye, is about 1 cm. long, milky-white in colour, cylindrical in shape with tapering extremities. Microscopically, its body is seen to be thickly studded with minute warty projections, each tipped with short stout bristles. Two suckers, one behind the other, are seen on the under surface of the body, near the anterior extremity. Under the microscope it will also be seen that the body of the worm is not cylindrical, but thin and flattened, and that the lateral margins of the body are folded towards the ventral surface to form a long open canal—the gynecophoric canal—in which the female lies during the period of sexual activity.
The female worm is much longer and thinner than the male and is often found lying within the gynecophoric canal, generally with part of the anterior and posterior extremities protruding. She can, however, completely withdraw herself into the canal. (Figs. 1 and 2.)
The most common habitat of the worm is the portal vein and its tributaries within the liver.
Here the worms are small, often very small, are not yet sexually active, and the male and female occur separately, not coupled. Exceptionally, however, coupled pairs of worms may be met with in this situation.
The worms are also found in the mesenteric veins and their larger tributaries. Here they are larger than those found in the portal vein and mostly occur as coupled pairs. They are sexually mature, but the female does not contain many ova.
The other common habitat of the worm is the vessels of the sub-mucous tissue of the bladder and rectum and, to some extent, also, of other parts of the intestinal tract.
Worms found in these situations are fully developed, physically and sexually, they nearly always occur in coupled pairs, and...
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