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.
Citation
Doctor of medicine,University of Nairobi,1981.Publisher
medicine