Sonographic changes following splenectomy for portal hypertension in Schistosoma mansoni

Eleven patients with portal hypertension due to infection with Schistosoma mansoni underwent splenectomy and devascularization operations. The patients were examined with ultrasound once preoperatively and twice postoperatively over a period of about 6 months. Following surgery there was significant and sequential reduction in the diameter of the portal vein at the hilum and the splenic vein at the pancreas. The liver lengths and index of liver size did not change significantly. No changes in the degree of periportal fibrosis could be detected.

Sonographic organometry in Brazilian and Sudanese patients with hepatosplenic schistosomiasis mansoni and its relation to the risk of bleeding from oesophageal varices

Fifty-nine patients with hepatosplenic schistosomiasis mansoni were investigated by sonography in Northeast Brazil and Central Sudan. The sizes of the organs usually involved in this disease were quantitatively assessed according to a standardized protocol, and measurements were adjusted to the body height of the individual. The results were compared with those of healthy controls matched by sex, age, geographical origin and socio-economic status. Considerable differences were found between patients and controls as well as between residents from the two areas. The liver of both patients and controls from the Sudan was significantly smaller than that of patients and controls from Brazil. Only in Brazil, but not in the Sudan, was the left liver lobe larger in patients than in the controls. The diameter of the portal and the splenic vein, the spleen size and the thickness of the gallbladder wall were significantly increased in patients from both areas. The increase of the portal and splenic vein diameter was significantly correlated with the degree of hepatic periportal fibrosis and the frequency of bleeding from endoscopically proven oesophageal varices in the patients, irrespective of their geographic origin. In contrast, such correlations were not found for the degree of splenomegaly nor for the degree of gallbladder-wall thickening. It is concluded that standardized sonographic organometry permits the assessment of morbidity in hepatosplenic schistosomiasis mansoni under different endemic conditions. Especially the measurement of the portal vein diameter may allow estimation of the risk of gastrointestinal haemorrhage in these patients.

A review of the literature on the use of ultrasonography in schistosomiasis with special reference to its use in field studies

This review presents an outline of the pathology resulting from Schistosoma mansoni infections, and the ways in which it can be investigated. The use of ultrasonography is covered in detail. Ultrasonography can provide direct information about lesions in internal organs, and thus provide information about patterns of morbidity and about the regression of pathological changes after treatment. The method is non-invasive, and can be used under field conditions. Ultrasonography is valuable for the study of hepatosplenic pathology, to detect lesions such as the development of periportal fibrosis and the enlargement of the portal vein, which can indicate the development of portal hypertension. This may lead to a severe outcome, including bleeding from oesophageal varices, which is a principal cause of death from S. mansoni infection. A problem with the use of ultrasonography is that the mild lesions likely to be observed in population surveys are not always easy to assess. Ultrasonography has already been used in a number of epidemiological studies of S. mansoni infection, and has proved to be feasible and useful. However, the methodology used for ultrasound studies has varied considerably, so that it is difficult to make valid comparisons between results obtained in different places or at different times. A standardized methodology for making observations and recording the results is needed if the full potential benefit of using ultrasound in the monitoring of schistosomiasis control projects is to be realised.

Inter-observer variance in ultrasonographical assessment of Schistosoma mansoni-related morbidity in young schoolchildren

49 Sudanese schoolchildren aged 6-9 years with Schistosoma mansoni infection were ultrasonographically examined by two independent observers in a double-blind fashion. The first observer recorded normal appearance of the liver in 23 cases, whereas the second observer recorded the appearance as normal in 33 cases. There were 23 concordant observations. For Grade I periportal fibrosis (PF), 13 observations were concordant. PF Grade II was rarely observed (2 versus 3 cases), and Grade III was not recorded at all. In total, 38 out of 49 observations were concordant (77.5%). These preliminary data from two ultrasound observers, from observations on a limited number of patients, can be seen as an indication of a potential inter-observer variation of around 20% for the distinction between the absence of PF and a low level of PF.

The use of diagnostic ultrasound in schistosomiasis--attempts at standardization of methodology. Cairo Working Group

This paper summarises the conclusions of a workshop held in Cairo in 1990 to discuss the standardization of the use of diagnostic ultrasound in schistosomiasis. For epidemiological purposes, it is very important that ultrasound examinations should be carried out and recorded in a standardized way, in order to ensure that results obtained in different places and at different times can be compared. The workshop did not attempt to produce final recommendations, but it did make tentative proposals in a form suitable for field testing. The paper discusses the general problems involved in carrying out and recording ultrasound examinations in a standardized way. The special points involved in assessing lesions due to the three main forms of schistosomiasis are then considered in detail. Methodology that can be used in epidemiological work with large numbers of people is emphasised.

Ultrasonographical investigation of periportal fibrosis in children with Schistosoma mansoni infection: reversibility of morbidity twenty-three months after treatment with praziquantel

In February 1987, 322 Sudanese school children were diagnosed for Schistosoma mansoni infection and treated randomly with praziquantel (either 20 mg/kg or 40 mg/kg body weight). A followup of these subjects was carried out in January 1989. This treatment resulted in a substantial reduction of egg output. Patients underwent complete abdominal ultrasonography and periportal fibrosis of the liver was graded into three degrees of severity. The proportion of patients with periportal fibrosis decreased from 36.6% in February 1987 to 21.7% in January 1989. At the time of followup, higher grades of periportal fibrosis (grades II and III) were encountered in only 4.3% and 0.3% of these patients, respectively, compared with 21.1% and 5.9%, respectively, before therapy. This was paralleled by a significant decrease in hepatomegaly from 10.9% to 7% of the patients. In contrast, the rate of splenomegaly showed a slight increase during the period of observation. The different dosage regimens of praziquantel did not result in a significantly different reversibility of periportal fibrosis or a decrease in egg excretion. The reversibility of specific liver lesions 23 months after antischistosomal therapy with praziquantel was substantial. The improvement was greater at 23 months than that obtained seven months after treatment.

Grading of hepatic schistosomiasis by the use of ultrasonography

Forty-three subjects with pure hepatic schistosomiasis having ultrasonographic assessment of periportal fibrosis were grouped according to the thickness of their portal tracts: grade I = 3-5 mm, grade II = greater than 5-7 mm, and grade III = greater than 7 mm. A history of hematemesis, blood transfusion, sclerotherapy, and lower limb edema correlated with the ultrasonographic grade of periportal fibrosis. With increasing grade, the average liver size was smaller and the average spleen size was larger, as determined by physical examination and by ultrasonography. Abnormalities in serum enzyme levels were more frequent in those with thicker portal tracts. Greater diameters of the portal and splenic veins and ultrasonographically detectable collateral blood vessels were associated with increasing thickness of portal tracts. The grade of endoscopically determined esophageal varices was highly correlated with the grade of periportal fibrosis. We concluded that this method of grading accurately reflects the hemodynamic changes and provides a good estimate of the clinical status of patients who have periportal fibrosis due to schistosomiasis mansoni. Where available, it should replace clinical grading based upon the liver and spleen size as detected by physical examination.

Duplex Hemodinamic evaluation of hepatosplenic mansoni schistosomiasis

Conventional ultrasonography highly contributes to a non invasive diagnosis of HS schistosomiasis (Cerri et al., 1984). The introduction of Doppler allowed new advances in the knowledge of the portal dynamics of this disease (Taylor et al. 1985; Moriyasu et al., 1986). The aim of this paper was to analyze the hemodynamic behavior of the portal vessels, considering caliper, maximum flow speed, direction of flow and preferential disposition of the collateral vessels. Thirty two patients with schistosomiasis mansoni with confirmed hepatosplenic form (HSSM), were analyzed. Fourteen patients with the intestinal form, have been analyzed as a control group. The results demonstrated that the maximum speed of the portal vein in the two groups has not been significantly different. Nevertheless, the diameter of the PV in the hepatosplenic group has been larger. The splenic vein presented speed and caliper larger than the superior mesenteric vein. The hepatic artery has been detected in only 40% of the cases. The hepatic veins presented normal caliper and spectral pattern. The duplex proved to be an useful technic complementary and non-invasive, in the study of HSSM.

The value of ultrasonography in assessment of portal hypertension in hepatosplenic schistosomiasis

Ultrasonography can reveal most of the manifestations of portal hypertension complicating hepatosplenic schistosomiasis. However, direct demonstration of gastroesophageal varices by ultrasonography is still very difficult. An attempt was done to correlate sonographic features of portal hypertension with the degree of fibrosis to screen patients having varices and predicting their chance of bleeding. The results obtained were found to be consistent with the esophagogastric endoscopy and with history of hematemesis. Four parameters were used, size of spleen, degree of periportal fibrosis, presence of collaterals and portal vein diameter. A pilot field survey was also done adopting the same principle.

Morbidity due to Schistosoma mansoni among sugar-cane cutters in Zimbabwe

Quantitative determination of Schistosoma mansoni infection was carried out on 1995 cane cutters of the Hippo Valley and Triangle Sugar Estates. A total of 315 cutters were chosen for the study on the basis of S. mansoni infection and lack of anti-schistosomal chemotherapy during the previous three years. Stool consistency and blood and mucus in stool were determined for all the infected cutters. Overt and occult blood in stool was detected in a significantly high number of infected people compared to the control subjects (chi 2 p less than 0.001). However, the blood loss was found to have no anaemia-producing effect as determined by haemoglobin and red blood cell counts. Watery stool was prevalent among people with egg output exceeding 500 eggs per gram of stool. Mucus in stool was found to be more prevalent among infected people compared to the control subjects but the difference was not significant (p greater than 0.05). Symmer's periportal fibrosis (PPF) of various degrees of severity was detected in 47% of the infected people and grade one liver fibrosis was found in 7.5% of the control subjects (p less than 0.0001). Some 54.5% of those infected complained of abdominal pains compared to 35% of uninfected controls (p less than 0.01). There was a significant difference in the rate of absenteeism from work due to abdominal pains and diarrhoea among the infected and uninfected cane cutters (p less than 0.02).

Schistosomal periportal fibrosis in Zimbabwe: use of ultrasound in patients with oesophageal varices

Ultrasound (U/S) imaging of liver was used in a prospective study of 62 consecutive patients with oesophageal varices in the central hospitals in Harare; 50 had haematemesis. U/S changes of Symmers's periportal fibrosis (PPF) were graded from mild (grade 1) to gross (grade 4). 46 patients (74%) had U/S features of PPF: 7 were grade 1, 7 grade 2, 29 grade 3, and 3 grade 4. Patients with PPF were more likely to have bled (P less than 0.05) and were less likely to have ascites (P less than 0.05) than those without PPF. Spleen or liver size or grade of varices did not correlate with the U/S grade of PPF. Rectal snips were positive for schistosome ova in 19 of 28 cases with PPF and 2 of 7 cases without PPF. Patients with PPF were more likely than those without PPF (P less than 0.005) or controls (P less than 0.0001) to have spent their childhood in an area of Zimbabwe with a high prevalence of Schistosoma mansoni. Schistosomal PPF appears to be a common cause of portal hypertension in Zimbabwe. It is strongly associated with childhood spent in areas of high S. mansoni prevalence.

Ultrasonographical investigation of periportal fibrosis in children with Schistosoma mansoni infection: reversibility of morbidity seven months after treatment with praziquantel

Five hundred thirty six Sudanese schoolchildren with Schistosoma mansoni infection were treated at random with either 20 mg or 40 mg/kg praziquantel. Seven months later 420 children could be reinvestigated by ultrasonography. Reduction of egg excretion and reversibility of sonographically-proven periportal fibrosis (PF) was not significantly different in the two groups. Schistosoma mansoni-induced PF grade II decreased from 22.9% to 6.7% and grade III from 5.2% to 1.6%. An increased prevalence of PF grade I, from 10% to 29.8% of the investigated patients, was observed. This increase was caused partly by a downshifting of patients who had PF II (n = 45) and PF III (n = 8) before therapy, but also by patients who developed PF I in the seven months after therapy (n = 56). The overall percentage of patients with PF before and after treatment was 38.1%. Of 420 children, 17.4% increased in their PF grade, 55% remained at the same level and 27.6% improved. Children younger than 11 years of age had a higher rate of complete reversibility than older ones. The percentage of patients with hepatomegaly decreased significantly (11.6% to 6.9%; p = 0.001). The rate of splenomegaly remained unchanged. It was concluded that within seven months therapy with praziquantel resulted in a considerable qualitative improvement of PF in Sudanese schoolchildren with S. mansoni infection.

Hepatitis B vaccination in children infected with Schistosoma mansoni: correlation with ultrasonographic data

Forty-one schoolchildren with positive stools for Schistosoma mansoni eggs and 39 age- and sex-matched children with negative stools were given 3 doses, 5 micrograms each, of a plasma derived hepatitis B vaccine. Their sera were examined 3 and 9 months after the third dose for hepatitis B surface antibody (anti-HBs). At 9 months after vaccination, both the number of responders and the mean of antibody titers were significantly higher in the control group than in the group infected with S. mansoni (97% vs. 56% and 334.8 +/- 192.9 vs. 67.7 +/- 74.4 mIU/ml). There was a negative correlation between anti-HBs titers and the long diameter of the spleen as well as between the titers and the long diameter of the spleen and the liver span in the mid-clavicular line (right lobe) taken together. There was also a positive correlation between anti-HBs titers and the diameters of the portal vein. There was no correlation between anti-HBs titers and any of the following 3 parameters: liver span in the mid-clavicular line (right lobe) alone, liver span in the middle line (left lobe) alone, and the degree of thickness of the periportal fibrosis. There was also no correlation between anti-HBs titers and egg counts in the stools. An interpretation of these findings was made in the light of the role of phagocytic activity of the liver and spleen as well as of porta-caval shunts in the immune mechanism.

Ultrasonographic evaluation of gallbladder function in patients with Schistosoma mansoni infection

Gallbladder function was studied in 22 patients with portal hypertension due to advanced Schistosoma mansoni infection and in 17 healthy adults. The fasting volume of the gallbladder was significantly less in patients than in controls. The gallbladder wall was grossly thickened in the study group. There was a significant difference between the patients and controls in the reduction of gallbladder volume following a fatty meal. Although the portal vein diameter and the splenic volume were significantly larger in study patients, no significant correlation could be detected between the reduction in volume or wall thickness of the gallbladder and any of the relevant sonographic features of schistosomiasis-induced portal hypertension.

Calcification of the large bowel in schistosomiasis demonstrated by computed tomography

Four cases are described in which large bowel calcification was demonstrated on CT. All four patients had mixed infection by Schistosoma haematobium and mansoni, the latter being responsible for this abnormality. Intestinal calcification by S. mansoni is unusual, but is especially well demonstrated by computed tomography.

[Chronic pulmonary form of schistosomiasis mansoni. Clinico-radiologic evaluation]

One hundred and fifteen patients with schistosomiasis mansoni were studied: 31 with a normal chest x-rays and no signs of pulmonary hypertension (PH) and 84 with x-rays compatible with cardiopulmonary abnormalities (73 without symptoms and 11 with symptoms of PH). The chronic pulmonary form (CPF) without pulmonary hypertension is frequent and benign. There was no association between the CPF and the hepatosplenic form (HEF), nor with age, sex or patient origin. Pulmonary hilum alterations were the most common x-ray findings, followed by parenchymatous abnormalities (micronodules). The CPF was associated with a low to medium worm burden. The incidence of CPF with pulmonary hypertension is low but usually related to significant heart abnormalities. It is more common in patients over 12 years, with the HEF of the disease and has no correlation with sex, race or place of birth. Chest x-ray alterations are seen with similar frequency both in parenchymatous and hilar regions.

Measurement of schistosomiasis-related morbidity at community level in areas of different endemicity

Among the indicators of schistosomiasis morbidity currently used in control programmes, ultrasound has been found to be a safe, non-invasive and efficient technique for detecting schistosomiasis-related lesions and for assessing the effect of treatment on their resolution. Three case-studies from East Africa, in areas of different endemicity for Schistosoma haematobium, using ultrasound are described and their results related to indirect measurements of the disease (e.g., haematuria, egg counts). This review reveals that cross-sectional ultrasound surveys can be used to quickly assess subsamples of populations in areas of different endemicity, in order to make decisions about sampling strategies in control programmes. The association between the intensity of infection and urinary tract abnormalities is reviewed and evaluated. One case study provides information on the resolution of S. haematobium-related uropathy after treatment; this information is crucial in order to maintain low levels of morbidity in a community. The role of ultrasound is further discussed, particularly as a tool to complement and validate indirect morbidity control measurements. The validation of such indirect measurements for use as a basis for public health decisions is important because they can be carried out by existing health care services in many areas.

Pulmonary schistosomiasis mansoni: post-treatment pulmonary clinical-radiological alterations in patients in the chronic phase: a double-blind study

A double blind trial was set up to study the pulmonary effects of specific treatment with oxamniquine of 40 patients with chronic schistosomiasis mansoni. Radiological alterations characterized by bronchopneumonitis were seen in 17.5% of the patients after treatment, but in none of the placebo group; non-migratory condensation occurred between 25 and 72 h after treatment, with a mean duration of 7 d. 86% of the patients showed spontaneous healing with no radiological sequelae after 30 d of follow-up. Slight pulmonary clinical manifestations without any functional repercussions were also seen. The alterations were probably related to the host-parasite interaction, and the lesions may have been caused by deposition of immune complexes in the lungs with local activation of complement.

Bowel x-ray alterations in acute human schistosomiasis

A radiological study of the small intestine of 17 untreated patients in the acute phase ofschistosomiasis was performed. Twelve patients (70% of total) had alterations: nine had clear-cut thickening of the duodenal and jejunal folds, one flocculation, one fragmentation and one thickening of mucosae, flocculation and fragmentation of the barium column. There was no correlation of the gastrointestinal symptomatology (vomiting, diarrhoea, dysentery, hepatomegaly) neither with the parasitological load nor with the x-ray alterations.

Schistosoma mansoni in the spinal cord: a correlation between operative and radiological findings

Images

Liver scintigraphy in chronic hepatosplenic schistosomiasis. A predictor of disease severity

Liver-spleen scintigrams were performed in 42 patients with chronic hepatosplenic schistosomiasis. The scan patterns found are described and classified in five stages of increasing hepatic involvement. The scintigraphic classification correlates well with clinical parameters of disease severity. With higher stages, the number of symptoms and the severity of complications increase. The liver-spleen scan provides a simple and accurate means to determine extent of hepatic involvement and probabilities of complications in this disease.

Aortic aneurysm caused by schistosomiasis

Images

Cerebral atrophy: a schistosomiasis manifestation?

Preliminary studies with sonography indicated that a reduced brain mantle index and dilated ventricles were frequently seen in patients with chronic Schistosoma mansoni infection. Computerized tomography (CT) was used to confirm our earlier observations and to obtain more accurate measures. Brain scans of 25 patients with chronic S. mansoni infection showed mild to moderate degrees of cortical atrophy in 9 cases (36%) and central atrophy in 3 (12%). The remaining 16 subjects and 10 controls showed normal brain scans. The present study is the first report documented by CT showing a significant correlation between chronic S. mansoni infection and cerebral atrophy.

111In-labeled eosinophils: localization of inflammatory lesions and parasitic infections in mice

Based upon recent development of practical isolation techniques for eosinophils, labeling and in vivo imaging of eosinophils has been achieved. Isolation of cells was performed utilizing a Percoll density gradient. The eosinophils were subsequently labeled by a modified 111In-oxine method. Migration of eosinophils in response to intradermal ear-pinna injections of SEA (soluble schistosoma egg antigen), S. mansoni eggs, E. coli, and turpentine was followed with gamma-ray camera imaging from 4 to 48 h. Maximal localization, determined by Gamma 11 data processing, occurred by 4-h post-injection of radiolabel. SEA and S. mansoni eggs provided a greater stimulus for localization than E. coli or turpentine. Neutrophils did not preferentially accumulate. Tissue distribution of labeled eosinophils was greatest in the spleen, followed by liver and bone. 111In-labeled-eosinophil scans are sensitive to parasitic infections, although somewhat nonspecific.