OCCURRENCE OF B1LHARZIA 



6 9 



at the Cairo Hospital, and is remarkable from its abundance on 

 the east coast and inland countries of Africa from Egypt to the 

 Cape, as well as in the districts bordering Lake Nyassa and the 

 Zambesi river, while westwards it occurs on the Gold Coast. 

 Mecca is a source of infection whence Mohammedans carry the 

 disease to distant places. In Egypt about 30 per cent of the 

 native population is affected by the serious disease known as 

 Haematuria, resulting from the attacks of Bilharzia, so that, of 

 the many scourges from which in Africa man suffers, this one is 

 perhaps the most severe. 



The worm is found usually in couples, which have been proved 

 to be male and female individuals (Fig. 34), 

 often in considerable numbers in the veins 

 of the pelvic region, chiefly the veins of the 

 bladder and of the large intestine, and it is 

 tolerably certain that Bilharzia enter these 

 vessels from the portal vein. Their long 

 slender bodies enable them to penetrate 

 into the finer vessels, which get partially 

 or entirely choked up, and the circulation 

 accordingly impeded. But the most serious 

 consequences are observed in the urinary 

 bladder. The mucous membrane is swollen 

 and inflamed here and there, chiefly on 

 the dorsal surface, the capillaries appear 

 varicose and covered with mucus, mixed 

 with blood-extravasations in which Eil- 

 harzia-eggs are noticeable. The eggs also 

 cause numerous swollen knots in the sub- 



~, ,, ., ,. 

 inUCOUS tissue. Should the disease not 



pass beyond this stage (and such is usually 

 the case, especially in South Africa), a 

 temporary haematuria ensues. The urine, 

 which is only expelled with great effort, 

 accompanied by intense pain, is mixed with blood, mucous clots, 

 and masses of J3ilharzia-eggs, from which some of the embryos 

 have already hatched out. The symptoms, however, may gradu- 

 ally pass away, and a more or less complete recovery accomplished. 

 The disease may indeed be of a far less severe character, and may 

 not interfere with the usual occupations of the patient ; but, on 



FIG. Si.BilhansiH 



tubia Cobb. x 10. The 

 female (9) lying in the 

 gynaecophoric canal of the 

 male ( <J ). d, Alimentary 

 canal ; ms, oral sucker of 

 male ; rs, ventral suckers. 

 ( After Leuckart.) 



