Epidemiology And Urological Complications Of Schistosomiasis Haematobium

Abstract

The literature review covered tile development of knowledge about Schistosomiasis from the discovery of the worm by Bilharz in Egypt, the disovery of the intermediate host by Miyairi and Suzuki in Japan to the recent epidemiological and clinical reports. After Bilharz, subsequent work in Egypt evolved around the epidemiology and control of the disease with some sporadic reports on the clinical 3spects of bilharziasis. The severity of the disease caused concern right from the time of Lord Kitchener. Although the presence of the disease was recorded in East Africa as early as 1911, its clinical importance was not appreciated. Earlier work was basically epidemiological aimed at establishing the prevalence of the disease. It was Forsyth and his co-workers who first revealed the gravity of the urological complications of bilharziasis in North-west Tanganyika and Zanzibar. The systematic documentation of surgical methods for the treatment of these conditions besides the work of Makar in Egypt and Honey in Rhodesia, was not attempted. This study was prompted by the knowledge, from clinical observatons, that complications of schistosomiasis haemotobium cause considerable morbidity and mortality in the Sukumaland. The objectives of the 6tudy were to establish the prevalence of the urological complications of bilharziasis, to test the various methods of investigation and to assess surgical treatment. A prevalence survey was thus conducted at Tinde, an area within the radius served by the hospitals in which the author worked. Mid-day urine samples were collected from the unselected population of five villages which form Tinde ward. The formalin preserved specimen were examined for Schistosoma haematobium ova using 10 mls centrifuged deposit method. All together 3687 people were examined and 1921 were found positive, a prevalence of 52.1%. The maximum prevalence occurred at the age of 10 years and that same age group had the heaviest egg load. A clinical study of the random sample of the positives from two villages at the opposite ends of Tinde was done to assess the prevalence of the urological complications. The sample of 78 people were admitted and 75 were investigated. Three were eliminated because of pregnancy. The investigations included the clinical features, urinalysis, intravenous pyelography and cystoscopy. Radiological abnormalities, ureteric lesions, bladder filling defects, bladder calcification and urinary calculi, were detected in 69.3%. The commonest findings were ureteric lesions, seen in 62.7%. Most of the ureteric lesions produced definite radiological defects but without proximal dilatation. They were regarded as early or minor lesions (grade I). The lesions which caused dilatation of the ureter and pelvis without alteration of the shape of the calyces (grade II) and those causing hydronephrotic changes (grade III) were regarded as severe lesions. Severe ureteric lesions therefore formed 25.3%. The younger children had more of grade I lesions while the older children had more severe lesions. It was also noticed that the lesions were more common in older children. Ureteric lesions were present in 43.7% of the children aged 2 - 10 years and 60% of the children aged 11 - 20 years. Endoscopic facilities were available for the examination of all age groups. The earliest bladder mucosal lesions observed were discrete ova in the mucosa with no sign of inflammation around them. These changes were frequently associated with bullae and mucosal polyps with occasional intramucosal haemorrhages. They correspond to the early ureteric lesions. The children with back pressure changes were observed to have granulomatous and tuberculous lesions, established chronic inflammation. Late mucosal changes consisting of sandy patches, discrete tubercles and deformity of the ureteric orifices were common in adults. Bladder mucosal biopsy showed some live ova even in late lesions. The incidence of double infection of S. mansoni and haematobium was low, 5.3%. Other investigations w ere not found helpful for assessing the extent of urinary tract damage in the early stages. More than half of the people had eosinophilia. The second part of the study is a review of the patients with urological complications of schistosomoiasis treated in Mwandui Hospital and followed up for more than three years. A total of 94 patients had operations for ureteric stenosis, urinary tract calculi, contracted bladder and carcinoma of the bladder. The indications for operation in ureteric stenosis were worked out to be grade IV lesions (non-functioning kidney), grade III lesions and grade II lesions with severe symptoms or recurrent upper urinary tract infection. The operative procedures included simple ureteric meatoplasty, ureteroneocystostomy, bladder flap and ureteroileocystoplasty. Anti-reflux procedures were sacrificed in favour of wide stomata to avoid restenoses. The indications for each procedure are outlined. The obstructive stenoses were efficiently corrected by these plastic procedures but the functional results were limited by the extent of structural changes that had occurred before operation. The gross hydronephrotic kidneys have not been seen to revert to normal. The best time to operate is immediately blunting of the calyces is noticed. Earlier operation is not advisable because many patients w t th dilated ureters show no sign of progressive deterioration. No other aetiological factors were observed in association with the urinary tract calculi, many of which were "asymptomatic" but caused extensive destruction ot the urinary tract. Early lithotomy for renal and ureteric calculi was found expedient. Even small ureteric calculi rarely pass down on conservative treatment because of stenosis of the segment of the ureter within the muscular layers of the bladder wall. Bladder calculi are usually large enough to require cystotomy and removal. The rate of post-operative infection following vesico-lithotomy was found to be high. The common presenting symptoms of carcinoma ol the bladder were haematuria, pyuria, hypogastric pain, dysuria and frequency. More than a third of the patients had palpable suprapubic masses on admission. The tumours were often large and sessile. Clinical staging and biopsy were done at cystoscopy. The majority, 71%, were squamous cell carcinomas. Only two patients were suitabIe for electrosurgical procedures. The rest of the tumours infiltrating the bladder muscle were assessed for open operations. All tumours which were in stage T2 and T3 were offered partial cystectomy or total cystectomy if the former was contraindicated. The merits and disadvantages of both operations are discussed. Post-operative follow up tends to show that partial cystectomy is a better operation.