Ultrasonographical assessment of morbidity in schistosomiasis mansoni in Madagascar: a community-based study in a rural population

Baseline Liver Ultrasound Findings in Preschool Children From the Praziquantel in Preschoolers Trial in Lake Albert, Uganda

BACKGROUND

Periportal fibrosis is a late-stage manifestation of chronic infection with Schistosoma mansoni . Praziquantel (PZQ), the only drug available for the treatment of schistosomiasis, has limited effect in treating established morbidity. Preschool-age children (PSAC) are not considered to be an at-risk population for severe morbidity. However, the prevalence of periportal fibrosis in PSAC in S. mansoni endemic settings is unknown.

METHODS

As part of a phase II clinical trial comparing different dosing regimens of PZQ in children age 12-47 months infected with S. mansoni in Uganda ("praziquantel in preschoolers" trial), we present baseline results assessing liver ultrasound (US) findings as per the WHO Niamey Protocol.

RESULTS

A total of 7/347 (2%) PSAC had Image Pattern C with pipe stems and echogenic rings suggestive of periportal fibrosis, 29/347 (8%) had Image Pattern B and 58 (17%) had evidence of periportal thickening There were higher adjusted odds of periportal thickening with older age [odds ratio (OR): 1.04; 95% confidence interval (CI): 1.00-1.07], primary maternal education (OR: 1.04; 95% CI: 1.00-1.07) and being taken to the lake weekly (OR: 3.02; 95% CI: 1.19-7.63). A further 44/347 children (13%) had a rounded caudal liver edge which was associated with high S. mansoni infection intensity (adjusted OR: 3.31; 95% CI: 1.46-7.51).

CONCLUSIONS

Incipient schistosomiasis-related liver morbidity was detected in young children enrolled in the praziquantel in preschoolers trial. Adequate age-adjusted reference measurements for liver ultrasound findings in very small children are lacking but urgently needed. Schistosomiasis-related fibrosis may be delayed or averted with early and repeated PZQ treatment.

Serology- and Blood-PCR-Based Screening for Schistosomiasis in Pregnant Women in Madagascar-A Cross-Sectional Study and Test Comparison Approach

This work was conducted as a cross sectional study to define the disease burden of schistosomiasis in pregnant Madagascan women and to evaluate serological and molecular diagnostic assays. A total of 1154 residual EDTA blood samples from pregnant Madagascan women were assessed. The nucleic acid extractions were subjected to in-house real-time PCRs specifically targeting S. mansoni complex, S. haematobium complex, and African Schistosoma spp. on genus level, while the EDTA plasma samples were analyzed using Schistosoma-specific IgG and IgM commercial ELISA and immunofluorescence assays. The analyses indicated an overall prevalence of schistosomiasis in Madagascan pregnant women of 40.4%, with only minor regional differences and differences between serology- and blood PCR-based surveillance. The S. mansoni specific real-time PCR showed superior sensitivity of 74% (specificity 80%) compared with the genus-specific real-time PCR (sensitivity 13%, specificity 100%) in blood. The laborious immunofluorescence (sensitivity IgM 49%, IgG 87%, specificity IgM 85%, IgG 96%) scored only slightly better than the automatable ELISA (sensitivity IgM 38%, IgG 88%, specificity IgM 78%, IgG 91%). Infections with S. mansoni were detected only. The high prevalence of schistosomiasis recorded here among pregnant women in Madagascar calls for actions in order to reduce the disease burden.

Schistosoma mansoni Infection and Its Related Morbidity among Adults Living in Selected Villages of Mara Region, North-Western Tanzania: A Cross-Sectional Exploratory Study

Schistosoma mansoni is highly endemic in Tanzania and affects all age groups at different degrees. However, its control approach does not include adult individuals who are equally at risk and infected. To justify the inclusion of adult individuals in MDA programs in Tanzania, the present study focused on determining the prevalence of S. mansoni infection and its related morbidities among adult individuals. This was a cross sectional study conducted among 412 adult individuals aged 18–89 years living in selected villages of Rorya and Butiama districts located along the shoreline of the Lake Victoria. A pretested questionnaire was used to collect socio-demographic and socio-economic information of participants. Ultrasonographic examinations were conducted for all study participants using the Niamey protocol. A single stool sample was obtained from all study participants and examined for S. mansoni using the Kato-Katz technique. The study revealed a high prevalence of S. mansoni (56.3%), and the majority of infected individuals had a light intensity of infection. Ultrasonographic findings revealed that 22.4% of adult individuals had periportal fibrosis (PPF) (grade C–F), with 18.4% having grade C and D and 4% having grade E and F. Males had the highest prevalence of PPF (31.7% vs 10.8%, P<0.001). Organomegaly was common with 28.5% and 29.6% having splenomegaly and hepatomegaly, respectively. S. mansoni infection and its related morbidities included PPF, hepatomegaly, and splenomegaly were common among adult individuals. To reduce the level of transmission of S. mansoni infection, planned mass drug administration campaigns should include adult individuals living in these villages.

High seroprevalence of echinococossis, schistosomiasis and toxoplasmosis among the populations in Babati and Monduli districts, Tanzania

BACKGROUND

The neglected tropical diseases, echinococcosis, schistosomiasis and toxoplasmosis are all globally widespread zoonotic diseases with potentially harmful consequences. There is very limited data available on the prevalence of these infections, except for schistosmiasis, in underdeveloped countries. This study aimed to determine the seroprevalence of Echinococcus multilocularis, Schistosoma mansoni, and Toxoplasma gondii antibodies in populations from the Monduli and Babati districts in Tanzania.

METHODS

A total of 345 blood samples were collected from 160 and 185 randomly selected households from Babati and Monduli districts, Tanzania between February and May of 2012 and analyzed them using the enzyme linked immunosorbent assay. The antibodies were determined using the NovaLisa® Toxoplasma gondii IgG, NovaLisa® Schistosoma Mansoni IgG, NovaLisa® Echinococcus IgG and NovaLisa® Toxoplasma gondii IgM kits (Novatec, Germany).

RESULTS

The seropositivity estimated for E. multilocularis, S. mansoni, and T. gondii IgG was 11.3% (95% confidence interval (CI): 7.96-14.6), 51.3% (95% CI: 46.0-56.5), and 57.68% (95% CI: 52.5-62.9), respectively. The seropositivity for T. gondii IgM was 11.3% (95% CI: 7.96-14.6). Living in the Monduli district was found to be the main risk factor for IgG seropositivity for both schistosomiasis (OR =1.94; 95% CI: 1.23-3.08; p =0.005) and toxoplasmosis (OR =2.09; 95% CI: 1.31-3.33; p =0.002).

CONCLUSIONS

These results suggest that restricting disease transmission, implementing control measures, and introducing training projects to increase public awareness are imperative, particularly for the Monduli district.

Schistosomiasis in African infants and preschool children: let them now be treated!

The occurrence of schistosomiasis within African infants and preschool children has been much better documented in recent years, revealing an important burden of disease previously overlooked. Despite mounting evidence showing that treatment with praziquantel is safe, beneficial, and could be delivered within ongoing public health interventions, young children still do not have satisfactory access to this drug, and a significant treatment gap exists. Progress towards resolution of this unfortunate health inequity is highlighted, including the development of an appropriate paediatric praziquantel formulation, and present blocks are identified on securing this issue within the international health agenda.

Epidemiology and interactions of Human Immunodeficiency Virus - 1 and Schistosoma mansoni in sub-Saharan Africa

Human Immunodeficiency Virus-1/AIDS and Schistosoma mansoni are widespread in sub-Saharan Africa and co-infection occurs commonly. Since the early 1990s, it has been suggested that the two infections may interact and potentiate the effects of each other within co-infected human hosts. Indeed, S. mansoni infection has been suggested to be a risk factor for HIV transmission and progression in Africa. If so, it would follow that mass deworming could have beneficial effects on HIV-1 transmission dynamics. The epidemiology of HIV in African countries is changing, shifting from urban to rural areas where the prevalence of Schistosoma mansoni is high and public health services are deficient. On the other side, the consequent pathogenesis of HIV-1/S. mansoni co-infection remains unknown. Here we give an account of the epidemiology of HIV-1 and S. mansoni, discuss co-infection and possible biological causal relationships between the two infections, and the potential impact of praziquantel treatment on HIV-1 viral loads, CD4+ counts and CD4+/CD8+ ratio. Our review of the available literature indicates that there is evidence to support the hypothesis that S. mansoni infections can influence the replication of the HIV-1, cell-to-cell transmission, as well as increase HIV progression as measured by reduced CD4+ T lymphocytes counts. If so, then deworming of HIV positive individuals living in endemic areas may impact on HIV-1 viral loads and CD4+ T lymphocyte counts.

Metabonomic investigation of human Schistosoma mansoni infection

Schistosomiasis is a parasitic infection that is endemic in many developing countries in the tropics and subtropics afflicting more than 207 million people primarily in rural areas. After malaria, it is the second most important parasitic infection in terms of socio-economic and public health. Investigation of the host-parasite interaction at the molecular level and identification of biomarkers of infection and infection-related morbidity would be of value for improved strategies for treatment and morbidity control. To this end, we conducted a nuclear magnetic resonance (NMR) based metabonomics study involving a well-characterized cohort of 447 individuals from a rural area in Uganda near Lake Victoria with a high prevalence of Schistosoma mansoni, a species predominantly occurring in Africa including Madagascar and parts of South America. Cohort samples were collected from individuals at five time-points, before and after (one or two times) chemotherapy with praziquantel (PZQ). Using supervised multivariate statistical analysis of the recorded one-dimensional (1D) NMR spectra, we were able to discriminate infected from uninfected individuals in two age groups (children and adults) based on differences in their urinary profiles. The potential molecular markers of S. mansoni infection were found to be primarily linked to changes in gut microflora, energy metabolism and liver function. These findings are in agreement with data from earlier studies on S. mansoni infection in experimental animals and thus provide corroborating evidence for the existence of metabolic response specific for this infection.

Avaliação hepática e esplênica por ressonância magnética em pacientes portadores de esquistossomose mansônica crônica

OBJETIVO: Avaliar, qualitativa e quantitativamente, as alterações morfológicas hepáticas e esplênicas por ressonância magnética (RM) em pacientes portadores de esquistossomose mansônica crônica, e a reprodutibilidade do método na avaliação hepatoesplênica destes pacientes. MATERIAIS E MÉTODOS: Realizou-se estudo prospectivo em 28 pacientes esquistossomóticos submetidos à RM de abdome superior. Os exames foram realizados em equipamento com alto campo (1,5 T), utilizando-se bobina de corpo e bomba injetora para a administração do contraste endovenoso, e interpretados por dois examinadores independentes, que avaliaram a presença de alterações morfológicas hepáticas e esplênicas. A concordância interobservador e intra-observador foram medidas pelo teste kappa e pelo teste do coeficiente de correlação intraclasses. RESULTADOS: As variáveis qualitativas e quantitativas apresentaram boa concordância interobservador e intra-observador (kapa > 0,65 e r > 0,66, respectivamente). A maior concordância interobservador foi obtida para o diâmetro ântero-posterior do baço (r = 0,98). Os observadores identificaram redução do lobo hepático direito, aumento do lobo hepático esquerdo e caudado associado a esplenomegalia em quase todos os pacientes, e alargamento de fissuras, heterogeneidade do parênquima hepático, irregularidade de contornos, vasos periféricos hepáticos e fibrose periportal em mais de 82% dos pacientes. CONCLUSÃO: As alterações morfológicas hepáticas caracterizam-se pela redução do lobo direito e aumento dos lobos caudado e esquerdo, e as esplênicas, pela presença de esplenomegalia e nódulos sideróticos. A RM apresenta elevada reprodutibilidade na avaliação dessas alterações em pacientes com esquistossomose mansônica crônica.

Hepatosplenic morbidity in two neighbouring communities in Uganda with high levels of Schistosoma mansoni infection but very different durations of residence

Peri-portal fibrosis can be a serious sequelae of Schistosoma mansoni infection. Age or duration of exposure have been identified as important risk factors, but their relative importance cannot be easily separated. Here, we have compared two cohorts, aged 6-50 years and resident for ten years or since birth, from two neighbouring villages (Booma and Bugoigo) on the eastern shore of Lake Albert, Uganda. Parasitological measurements were similar, whereas the prevalence of peri-portal fibrosis was 5-fold higher in Booma. Data from the cohorts were pooled to assess the relative contribution of age and duration of residency on the risk of disease. Amongst adults, duration of residency was the critical risk factor--individuals aged 17-31 years resident for more 22 years had an almost 12-fold increased risk of fibrosis than those resident for less than 15 years. Height-standardised Splenic Vein Diameter (SVD), Portal Vein Diameter (PVD), Para-sternal Liver Length (PLL) and Spleen Length (SL) values were all higher in Booma, and each organometric parameter except PLL increased with the severity of fibrosis. Our results clearly demonstrate that duration of exposure is a critical risk factor for the development of peri-portal fibrosis and its sequelae in adults. This parameter should therefore be a routine measurement during epidemiological surveys of S. mansoni.

Treatment and re-treatment strategies for schistosomiasis control in different epidemiological settings: a review of 10 years' experiences

This paper reviews 10 years' experience with schistosomiasis control in different endemic settings in Africa, Asia and the Americas. Research projects, pilot programs and long-term large-scale programs with the objective of controlling morbidity have been included in the review. Major advances in diagnostic tools and rapid assessment techniques have evolved during the decade making it possible to follow changes in pathology after treatment and to get baseline epidemiological information at very low cost. At the same time prices of drugs like praziquantel has declined dramatically (to <US dollar 0.10 per tablet). Equipment for indicators of morbidity due to Schistosoma haematobium (e.g. urine reagent strips for micro-haematuria) have also become cost-effective. Cheap and simple parasitological methods for examination of urine and stool specimens have now been available for almost two decades. The impact of different control strategies on morbidity and the duration of the effects on pathology have been reviewed and suggestions for new treatment and re-treatment strategies are made based on the existing experience from different regions and countries.

Schistosomiasis mansoni in low transmission areas: abdominal ultrasound

In endemic areas with low prevalence and low intensity of infection, the diagnosis of hepatic pathology due to the Schistosoma mansoni infection is very difficult. In order to establish the hepatic morbidity, a double-blind study was achieved in Venezuelan endemic areas, with one group of patients with schistosomiasis and the other one of non-infected people, that were evaluated clinically and by abdominal ultrasound using the Cairo classification. Schistosomiasis diagnosis was established based on parasitologic and serological tests. The increase of the hepatic size at midclavicular and midsternal lines (in hepatometry) and the hard liver consistency were the clinical parameters able to differentiate infected persons from non infected ones, as well as the presence of left lobe hepatomegaly detected by abdominal ultrasound. The periportal thickening, especially the mild form, was frequent in all age groups in both infected and uninfected patients. There was not correlation between the intensity of infection and ultrasound under the current circumstances. Our data suggest that in Venezuela, a low endemic area of transmission of schistosomiasis, the hepatic morbidity is mild and uncommon. The Cairo classification seems to overestimate the prevalence of periportal pathology. The specificity of the method must be improved, especially for the recognition of precocious pathology. Other causes of hepatopathies must be investigated.

Study on histopathology, ultrasonography and some special serum enzymes and collagens for 38 advanced patients of schistosomiasis japonica

Thirty-eight cases clinically diagnosed as advanced schistosomiaisis were subject to splenectomy in Dongzhi County Special Hospital for Schistosomiasis because of portal hypertension, splenomegaly and/or hypersplenism. Liver biopsy was undertaken in all cases during surgical intervention. Before operation, ultrasonography on the liver and spleen was carried out. Also done was biochemical assay on several indices related to liver damage and fibrosis. Among the 38 cases, 24 were diagnosed as schistosomiasis by the finding of eggs in feces, 13 were diagnosed by positive serological test with IHA or COPT, and only in one case, the diagnosis of schistosomiasis was doubtful before operation. However, the eggs were found in the liver section upon histological examination. All the 38 cases had symptoms and signs of portal hypertension and most of them had general symptoms. Histories of hematemesis and melena were recorded in three cases. The causes of hospitalization were mainly splenomegaly and abdominal distension, and two were suffering from upper gastrointestinal bleeding. Upon histopathological examination, schistosome eggs were found in 33 out of 38 cases. Advanced schistosomaiasis was shown in 18 cases and schistosomiasis associated with hepatitis or cirrhosis was seen in other 20 patients. The main pathological changes were egg granulomas with different degrees of fibrosis and some differences in the pathological changes between schistosomal liver fibrosis (SLF) and mixed liver cirrhosis (both schistosome and hepatitis in origin) were seen. Compared with normal ultrasonography, in all the 38 cases, the length of the left and right liver, and the spleen, and the thickness of the left liver, the width of portal trunk, were all out of normal ranges. The differences between the patients and normal records were significant. However, there were no statistically significant differences in terms of above-mentioned indices as well as liver parenchyma changes on ultrasound between advanced schistosomaiasis and schistosomiasis complicated with hepatitis or cirrhosis (all P>0.5). According to WHO classification criteria on ultrasonography for schistosomiasis, among 20 cases combined with hepatitis or cirrhosis, 11 cases fell in Grade II, and nine cases in Grade III hepatic fibrosis, whereas among 18 cases with schistosomiasis fibrosis, 12 and six were in Grade II and III, respectively. The mean value of serum MAO, PIIIP, IVC and HA in the 38 cases were all significantly higher than normal range. However, no significant differences (all P>0.1) were seen between advanced schistosomiasis and those complicated with hepatitis or cirrhosis in terms of the levels of the four indices. The results showed that ultrasonography has its importance in the diagnosis and evaluation of liver fibrosis. However, in differentiation of the two types of liver damage, ultrasound does not provide important information. Histopathological examination, on the other hand, can provide useful information to identify the hepatic diseases.

Associating community prevalence of Schistosoma mansoni infection with prevalence of signs and symptoms

Information on the prevalence of morbidity is needed for re-calculation of the Global Burden of Disease (WHO) due to Schistosoma mansoni. This study presents a statistical association which can be used to predict the prevalence of morbidity from the prevalence of S. mansoni in a community. We collected data from field studies reporting prevalence of infection and prevalence of morbidity. Data on infection prevalence were standardised to a default diagnostic sensitivity (i.e. Kato-Katz technique 41.7 mg). The data were described by an expression related to logistic regression. We determined associations between prevalence of infection and prevalence of early morbidity (diarrhoea, blood in stool and abdominal pain), hepatosplenic morbidity and late morbidity (haematemesis and ascitis). Diarrhoea and blood in stool due to S. mansoni infection mainly occurs in communities with a high prevalence of infection. An influence on hepatosplenic morbidity is already present at low community prevalence of infection. For the aspecific symptom abdominal pain we did not find an association.

Morbidity of schistosomiasis mansoni in the highlands of Madagascar and comparison of current sonographical classification systems

To study the morbidity of schistosomiasis mansoni in the highlands of Madagascar, a cross-sectional study examined the extent to which liver fibrosis occurred in a rural community. The Managil and the Cairo classification systems were used. A second purpose was to investigate the effect of the measurements of 2 different branches of the portal vein (either segmental or sub-segmental branches) on the resulting staging of morbidity using the Cairo classification system. In a rice farmer village, 656 inhabitants (95% of the total population) were parasitologically examined; 561 patients underwent sonographic work-up based on the Managil scoring system, and in 307 randomized patients the outer to outer diameters of both the segmental and the sub-segmental branches of the portal vein were measured and scored by the Cairo classification system. Overall prevalence of schistosomiasis mansoni in the study area in 1994 was 68.3%. Upon sonographic examination and scoring by the Managil system 23.4% of the population showed liver changes (Managil degree I/II/III, 20%/2.5%/0.9%). Measuring the sub-segmental branches only and scoring by the Cairo classification, 19% of the study population were found to have liver changes, none with severe fibrosis. By contrast, 82% were found to have liver changes (Cairo degree 1/2/3, 70%/11%/2%) when the segmental branches were measured. The diameters of the sub-segmental branches were about two-thirds of those of the segmental branches. Both the Cairo- and the Managil-examination protocols have pitfalls. Using the Cairo classification, a considerable systematic error in classifying morbidity is created by measuring different branches of the portal vein.

Geographic differences in hepatosplenic complications of schistosomiasis mansoni and explanatory factors of morbidity

In a study in three neighbouring villages of southern Madagascar, where Schistosoma mansoni is hyperendemic, ultrasound examination using the Niamey protocol showed marked differences in the burden of disease from one village to another. Hepatosplenic schistosomiasis was more frequent in the village with the highest geometric mean egg counts and the earliest onset of infections, demonstrating that the morbidity induced by S. mansoni may vary greatly within a given area. True representativeness of study populations, a keystone of epidemiological studies, is mandatory to obtain a clear picture of a wide area. Ultrasound examinations in a small number of villages, or even a single one, may be a questionable approach. Using logistic regression analysis, the explanatory variables found to be significantly associated with a risk of severe hepatosplenic disease in our study were sex, age, village of residence and S. mansoni egg counts. On the other hand, a concurrent infection with an intestinal helminth seems to reduce the risk of severe hepatosplenic disease. Further studies should assess the role and possible impact of intestinal helminths on S. mansoni associated-morbidity.

Evolution of schistosomiasis-induced pathology after therapy and interruption of exposure to schistosomes: a review of ultrasonographic studies

Ultrasonography (US) is suitable for diagnosing schistosomiasis-related organic pathology and is particularly useful to assess its evolution after therapy and/or interruption of exposure to the Schistosoma parasites. Evolution of pathology after treatment: Regression of hepatic abnormalities in Schistosma mansoni-infected children and adolescents has been observed already from 7 months post-therapy on. This does, however, not occur in all cases: individual differences are great ranging from spontaneous regression of pathology without treatment to persistence of pathology lasting for years after therapy even without re-infection. Intensity and duration of exposure, different parasite strains, patients' age and genetic background all influence the evolution of pathology. In communities at continuous exposure to S. mansoni infection, repeated re-treatment is required to control hepatosplenic morbidity. In Schistosoma japonicum infection, changes around the portal tree may regress, but characteristic diffuse abnormalities described as 'network pattern' abnormalities do not resolve. In Schistosoma haematobium infection bladder abnormalities and urinary tract obstruction frequently resolve after treatment. Clinically relevant pathology may resurge from 1 year after therapy on if exposure continues. Subjects with more advanced pathology before therapy, appear to be at higher risk of pathology re-appearance. Evolution of pathology after interruption of exposure to schistosomiasis: Knowledge on the evolution of pathology induced by S. mansoni is limited to some reports in emigrants and to the experience of ultrasonographists working in areas, where transmission has been partially interrupted. Due to the longevity of the parasite, infection may last for many years. Even after elimination of the parasites severe pathology may persist for long. In S. haematobium infection spontaneous healing after interruption of re-exposure may occur, but cases have been reported where urogenital lesions led to complications many years after exposure. Contrary to hepatosplenic and urinary pathology, knowlegde on the evolution of other organic abnormalities is very limited: studies on the evolution of biliary abnormalities or intestinal pathology have not been published. Genital pathology may be induced by all Schistosoma spp. Post-therapy evolution of genital schistosomiasis is largely ignored. In some European travellers partial regression of prostatic fibrosis has been described. Schistosomal adnexitis leading to infertility and/or ectopic pregnancy has been reported occurring many years after interruption of exposure. Ultrasonography (US) has never been used to study the influence of schistosomiasis on pregnancy. Concluding, current knowlegde on the evolution of pathology after treatment and/or interruption of exposure is still fragmentary. Frequently, fibrosis reverses after therapy, but advanced pathology may persist for long. Therefore, the possibility of severe clinical complications has to be taken into account, even if the infection is inactive since many years. In interventions aimed at controlling schistosomiasis-related morbidity, evolution of pathology must be monitored by US in representative patient cohorts. Further systematic US-studies are needed not only on the evolution of hepatosplenic and urinary pathology but also on that of intestinal, biliary and genital pathology induced by schistosomiasis, as well as on the influence of schistosomiasis on the outcome of pregnancy.

Ultrasonography of the liver and spleen in Brazilian patients with hepatosplenic schistosomiasis and cirrhosis

Ultrasonography is now widely used in the diagnosis and management of patients with chronic Schistosoma mansoni infections. The present study was undertaken to evaluate the use of ultrasonography in patients with hepatosplenic schistosomiasis (HSS) with and without cirrhosis. Ninety-seven patients (52 males; median age 38 years, range 19-68 years) with HSS, 65 with well compensated (HSSC) and 32 with decompensated (HSSD) disease and cirrhosis, were systematically examined by ultrasound. Hepatic fibrosis was graded according to WHO recommendations. Typical atrophy of the right hepatic lobe accompanied by hypertrophy of the left lobe, with a rounded inferior marginal edge, was seen in 86 (88.7%) patients. Periportal fibrosis was observed in 83 (85.6%) cases and confirmed histologically in all. In 66 patients (68.0%) thickening of the gallbladder wall, associated with periportal fibrosis and extending from the branches of the porta hepatis, was noted. No evidence of biliary disease was found in these patients and gallstones were present in only 3 cases. Fourteen (43.8%) of the HSSD patients could not be classified for grade of fibrosis because of the advanced stage of cirrhosis related to hepatitis B or C viral infection. Of the remaining 18 HSSD patients, none had only grade I fibrosis (vs. 10.8% of HSSC, P = 0.054) and only 6 had grade II (vs. 67.7% of HSSC, P < 0.0005), while the frequency of grade III was significantly higher in the HSSD patients than in those with HSSC (37.5% vs. 21.5%, P = 0.049). These findings indicate that although ultrasonography is a very valid technique for assessing patients with pure HSS, and should be considered the 'gold standard', it is not reliable for assessing periportal fibrosis in patients with concomitant cirrhosis due to other causes.

Serum concentrations of sICAM-1, sE-, sP- and sL-selectins in patients with Schistosoma mansoni infection and association with disease severity

Increased serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1, CD54) and of soluble E- (CD62E), but not soluble P- (CD62P) and L- (CD62 L) selectins, were detected in Malagasy patients living in an hyperendemic focus of Schistosoma mansoni. Levels of sICAM-1 remained elevated for several months after treatment with praziquantel. Serum levels of ICAM-1, but not of other markers, were significantly correlated with the disease severity, as indicated by ultrasonographical data, and with some circulating fibrosis markers (at least hyaluronic acid). sICAM-1 level may reflect endothelial inflammatory reactions, probably harmful, in the liver and may be useful for monitoring morbidity evolution in schistosomiasis mansoni.

Reversibility of Schistosoma mansoni-associated morbidity after yearly mass praziquantel therapy: ultrasonographic assessment

A parasitological, clinical and ultrasonographic longitudinal study was undertaken in 1993 in a focus hyperendemic for Schistosoma mansoni infection in the central highlands of Madagascar. All the inhabitants were systematically treated with praziquantel. A complete examination and treatment were repeated each year. Among the 289 villagers who underwent the complete 3 years' follow up, 65.9% excreted eggs at the initial survey and the mean egg count of infected individuals was 202 eggs/g. In 1996, the prevalence of infection was 19.3% with a mean egg count of 27 eggs/g and, among inhabitants aged > 44 years, only one was found to be infected. The proportion of individuals complaining of bloody stool decreased from 24.9% in 1993 to 8.4% in 1996. Compared to the initial clinical examination, the age-adjusted prevalence of splenomegaly was significantly lower in 1996, but remained high: 62% in the 10-14 years age group and 59% in individuals aged > 24 years. Ultrasonographic examination after 3 years of praziquantel therapy showed a marked decrease of the overall prevalence of schistosomal hepatic fibrosis, from 28% in 1993 to 10.3% in 1996. This improvement had already been achieved during the second year of follow-up for most subjects. Usually, the reversal of morbidity affected individuals classified as stage 1 at the beginning of the study. Stage 3 was not observed in the last 2 surveys. One patient's ascites disappeared during the follow-up, associated with a significant reversal of periportal fibrosis. Our results indicate that repeated praziquantel therapy can lead to improvement of liver morbidity and the prevention of the development of schistosomal hepatic fibrosis, even in an old-established hyperendemic focus.

Schistosoma mansoni infection in a recently exposed community in Senegal: lack of correlation between liver morphology in ultrasound and connective tissue metabolites in serum

Four hundred and seventy villagers of Ndombo, a village with recently established intensive transmission of Schistosoma mansoni in the Senegal River Basin, were enrolled in a study with the intention to assess hepatosplenic morbidity. All patients were examined parasitologically and by ultrasound. Hepatic fibrosis serum markers were determined in 153 adult patients (aminoterminal propeptide of procollagen type III, hyaluronan and laminin). By ultrasound, about 60% of the patients showed early stages of hepatic involvement, 3% of the patients unequivocally showed severe hepatosplenic pathology (grade 3 according to the Managil classification), whereas in another study performed in the same village 3 years earlier, no patients with severe hepatosplenic pathology had been found. No correlation between the aminoterminal propeptide of procollagen type III, hyaluronan or laminin and the ultrasound findings could be established. These hepatic fibrosis serum markers do not seem to be a sensitive method to detect early hepatic fibrosis in schistosomiasis.

Occurrence of a community with high morbidity associated with Schistosoma mansoni infection regardless of low infection intensity in north-east Brazil

To establish the relationship between schistosome-associated morbidity and infection intensity in northeast Brazil, a parasitological and ultrasonographical study was carried out on 484 inhabitants of 4 villages (I, II, III and IV) in São Lourenço da Mata, Pernambuco, Brazil, where schistosomiasis is endemic. Quantitative stool examination using Knight's method demonstrated a high prevalence and moderate intensity of Schistosoma mansoni infection, and also that the subjects in village IV had a significantly lower prevalence and intensity of infection than those of the other villages. By ultrasonography, periportal fibrosis (PPF) and splenomegaly were found in 52% of the 299 infected subjects and 66% of the 146 infected subjects aged over 16 years old, respectively; 32% and 31% of the 299 infected subjects had abnormally high values of total bile acid (TBA) and alkaline phosphatase (ALP) activity, respectively. Liver and spleen size, PPF, and serum level of TBA and ALP were not correlated with infection intensity. There was no significant difference in the morbidity assessed by liver and spleen size, PPF, and serum analysis between the subjects in village IV and the other villages. These findings suggest the occurrence of a community with high morbidity associated with schistosomiasis regardless of low infection intensity.