Morbidity Of Schistosomiasis Mansoni Research Articles

Evaluation of Schistosomiasis Mansoni Morbidity by Hepatic and Splenic Elastography

In patients with Mansoni schistosomiasis, it is fundamental to evaluate the disease morbidity, which is reflected by the severity of periportal fibrosis (PPF) and parameters of portal hypertension, as analyzed by ultrasonography (US). This study aimed to evaluate the morbidity of schistosomiasis by hepatic and splenic point shear-wave elastography (pSWE) and relate this to US parameters. The PPF pattern, the diameter of the portal and splenic veins and the size of the spleen were evaluated by US. Then, liver and spleen pSWEs were assessed in 74 patients using the same equipment. As the PPF pattern progressed, the splenic pSWE values significantly increased. Significant correlations between splenic pSWE, the longitudinal and transverse lengths of the spleen and the diameters of the portal and splenic veins were observed. These findings, however, were not observed through hepatic pSWE. In conclusion, the splenic pSWE has the potential for assessing morbidity in schistosomiasis mansoni.

Morbidity of schistosomiasis mansoni in a low endemic setting in Ouro Preto, Minas Gerais, Brazil.

Despite the advances of disease control programs, severe forms of schistosomiasis are prevalent. The prevalence of the disease in areas frequented by tourists urges for permanent prevention and control. The aim of this study was to describe the morbidity of schistosomiasis in the district of Antônio Pereira, Ouro Preto, Minas Gerais, Brazil. The proportion of positives was defined by Kato-Katz coproscopy and urinary POC-CCA rapid test. Hepatosplenic form was diagnosed using abdominal ultrasound. Out of 180 participants,97 were examined by Kato-Katz, with 4 (4.1%) being positive. Thirty-four (22.1%) out of 154 were positive by POC-CCA. Five (2.8%) of 177 examined by ultrasound had hepatosplenic form. One of them had undergone splenectomy. One (0.6%)participant had myeloradiculopathy. Severe forms of schistosomiasis are still prevalent in low endemic areas and should be thoroughly investigated.

Streptozotocin (STZ) and schistosomiasis mansoni change the biodistribution of radiopharmaceutical sodium 99mTc-pertechnetate in mice

IntroductionTechnetium-99m (99mTc) is a radionuclide commonly used in nuclear medicine to obtain 99mTc-radiopharmaceuticals, which can be used to evaluate either physiological processes or changes related to diseases. It is also used in some experimental studies. Streptozotocin (STZ) administration to rodents causes lesions in very early stages and induces severe and permanent diabetes. Most morbidity of schistosomiasis mansoni is attributed to a granulomatous inflammatory response and associated liver fibrosis. This study was designed to investigate whether STZ administration and schistosomiasis modify the biodistribution of the radiopharmaceutical sodium 99mTc-pertechnetate. MethodsAdult female mice were infected by exposure to 100Schistosoma mansoni cercariae (BH strain, Belo Horizonte, Brazil) and euthanized after nine weeks. STZ was administered by a single intraperitoneal injection of 100mg/kg body weight, 3 or 15days before euthanasia. Each animal received 100μl of sodium (Na) 99mTc-pertechnetate (99mTcO4−) (740kBq). The animals were divided into four groups: A, uninfected; B, infected; C, uninfected + STZ; and D, infected + STZ. Blood, brain, thyroid, heart, lungs, liver, spleen, pancreas and kidneys were removed. The radioactivity was counted and the percentage of the injected dose of Na99mTcO4 per gram of the organ (% ID/g) was determined. ResultsThree days after the STZ injection, there was a decrease of Na99mTcO4 uptake by the liver, lungs, pancreas and kidneys (p<0.05) in group D when compared with group A. After 15days, the decrease of Na99mTcO4 uptake occurred also in the brain, thyroid, heart, spleen and blood (p<0.05) in group D. ConclusionWe demonstrated modifications on the biodistribution of Na99mTcO4 due to STZ administration and schistosomiasis, possibly due to physiological alterations in some organs. Advances in Knowledge and Implications for Patient CareThe biodistribution of radiopharmaceutical Na99mTcO4 should be carefully evaluated in subjects with diabetes and/or schistosomiasis infection.

Imaging techniques in the evaluation of morbidity in schistosomiasis mansoni

Over the last 20 years a great advance has been observed in many aspects of medicine, and the advent of novel imaging techniques is certainly amongst the most important. In schistosomiasis these new methods caused a revolution in the definition of the clinical forms of the disease and in the evaluation of its complications, such as, liver fibrosis, pulmonary hypertension and neuroschistosomiasis, as never before. Herein we present an overview of the image methods used to diagnose schistosomiasis mansoni nowadays.

Intensity of Schistosoma Mansoni, Hepatitis B, Age, and Sex Predict Levels of Hepatic Periportal Thickening/Fibrosis (PPT/F): A Large-Scale Community-Based Study in Ethiopia

To elucidate determinants of morbidity in schistosomiasis mansoni, a community-based study was undertaken involving 2,451 subjects (mean age, 18.8 +/- 15.3 [SD] years) from four endemic sites in Ethiopia. Overall prevalence of infection was 65.9%, reported blood in stools was 35.8%, and schistosomal periportal thickening/fibrosis (PPT/F) was 4.6%. Similarly, 43.2% were positive for at least one marker of hepatitis B virus (HBV), 5.3% were HBsAg positive, and 1.3% were anti-hepatitis C virus (HCV) positive. Prevalence of PPT/F increased significantly with increasing community prevalence and intensity of S. mansoni infection. In a multiple logistic regression analysis, intensity of egg excretion, markers of HBV infection, age, and male sex were significantly associated with PPT/F, whereas co-infection with other intestinal helminths was associated with lower odds for PPT/F. HCV was not associated with S. mansoni infection or with schistosomal PPT/F. In conclusion, integrated helminth control targeting school-aged children, who have the highest burden infection, should be used to substantially reduce the risk of periportal fibrosis.

Influence of specific treatment on the morbidity of schistosomiasis mansoni in an endemic area of Minas Gerais, Brazil

The authors describe the evolution of schistosomiasis mansoni in inhabitants of Capitão Andrade, Minas Gerais, Brazil, from 1973 to 1994. The prevalence of infection was 60.8% in 1973, 36.2% in 1984, and 27.3% in 1994. The evolution of the clinical forms of the disease in this group was as follows: unchanged in 76.7%, clinical progression in 8.4% and clinical regression in 14.9%. The reduction of the prevalence and severity of Schistosoma mansoni infection over the 21 years period, can be attributed to treatment of infected subjects performed in the area and to the installation of piped water in their dwellings.

Factors associated with Schistosoma mansoni infection 5 years after selective treatment in a low endemic area in Brazil

Five years after a single dose treatment, prevalence, intensity and morbidity of schistosomiasis mansoni were evaluated in Água Branca, a low endemic community in the South East Brazil (cure rate 94%). At community level, prevalence showed a decrease from 38.9 to 24.5% and the intensity of infection dropped from 119.5 to 38.9 eggs per g of faeces (epg). However, after the exclusion of immigrants, newborn children and individuals that had left the area after the first evaluation, the prevalence among the treated and followed population was not significantly affected. Multivariate analysis showed that the 10–29 age group and water contact for agricultural purposes were independently associated with the presence of infection on post treatment evaluation [OR 3.9 and 5.09, respectively]. A previous treatment among subjects older than 15 years was inversely associated [OR 0.58]. The authors wish to draw attention to the fact that mobility may lead to a serious bias in evaluating the impact of the control programme.

Hepatosplenic forms of schistosomiasis mansoni in the interior of Northeastern Brazil

Field studies on the morbidity of schistosomiasis mansoni were carried out in some rural endemic areas of Northeastern Brazil during the first semester of 1991. These cross-sectional studies were limited to the assessment of the gradient of clinical forms of the disease. The entire population present in a house-to-house survey was examined. Results have shown a reduction in the prevalence rates of the more severe form of schistosomiasis, the hepatosplenic form, when compared with previous similar studies made in the same areas during the 1960s and 1970s. Changes in prevalence rates of the severe clinical forms from the younger to the older age groups were observed.

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

Between June and November 1993, a parasitological, clinical and ultrasonographical survey was carried out in the mid west of Madagascar, among the whole population of a village where Schistosoma mansoni was endemic. S. mansoni eggs were found in the stools of 61·8% of the 544 individuals examined; the highest prevalence of infection (85·7%) was observed in the 15–19 years old age group. The most intense infections were recorded in the 10–14 years age group, in which the geometric mean egg count was 265 eggs/g of faeces and 34·3% of the individuals excreted more than 400 eggs/g. The egg count decreased steadily from the age of 15 years. Ultrasonographical examination was performed in 482 inhabitants older than 2 years: 29% of them presented definite schistosome associated liver alterations according to the proposals for staging S. mansoni infection made by the World Health Organization Cairo working group. Stage 3 was never observed in subjects under 30 years old. This is consistent with the need for a long-standing infection before serious lesions occur. A significant relationship between egg count and degree of liver alterations was found only in the 20–29 years age group.

Molecular and cellular basis of hepatic fibrogenesis in experimental schistosomiasis mansoni infection.

Morbidity in schistosomiasis mansoni occurs primarily as a result of the complications of hepatic fibrosis. Yet, the pathogenesis of schistosomal hepatic fibrosis is poorly understood. The fact that the hepatic egg granuloma is the hallmark of this infection suggests a potential role for granulomatous inflammation in hepatic fibrogenesis. Our studies in a murine schistosomiasis model indicate that hepatic granuloma cells secrete a variety of fibrogenic cytokines that may initiate the scarring process. Among these cytokines, we identified a novel protein that we designated fibroblast stimulating factor-1 (FsF-1). FsF-1 is a lymphokine that can stimulate fibroblast growth and matrix synthesis. A notable feature of hepatic fibrosis in this model is that production of FsF-1 and other granuloma-derived fibrogenic cytokines is down-regulated in chronic infection, an event that may be under immunological control. The spontaneous reduction of FsF-1 secretion presumably accounts for reduced scar formation late in infection of mice. In the context of relevant clinical studies, our findings engender the hypothesis that Symmer's fibrosis may develop in a small subpopulation of individuals as a result of immunogenetically-determined dysregulation of fibrogenic cytokine production.

The morbidity of schistosomiasis mansoni in the highland focus of Lake Cohoha, Burundi

Morbidity due to infection with Schistosoma mansoni was investigated in a recently discovered highland focus around Lake Cohoha, Burundi. The distribution of the infection was very focal and morbidity patterns in populations from an endemic area A (prevalence 38%, mean egg load of positive subjects 231 eggs per gram [epg]), a less affected area B (16%, 90 epg) and a virtually non-endemic area C (5%, 45 epg), were compared; apart from schistosomiasis, the profiles of these populations were highly similar. The overall frequencies of diarrhoea were 36%, 25%, and 19%, respectively; of abdominal pain 86%, 78%, and 83%; of fatigue 7%, 2%, and 1%; of left lobe hepatomegaly 30%, 18%, and 9%; of right lobe hepatomegaly 18%, 10%, and 5%; of splenomegaly 18%, 10%, and 7%. Organomegaly was generally mild, even in area A. Within area A, the association between the presence of infection and diarrhoea, fatigue, hepatomegaly and splenomegaly was significant, but far less impressive than the results of the community-based comparison with areas B and C. The correlation with intensity was limited to an increased prevalence of diarrhoea and fatigue in the highest egg count group, and a more gradual increase (varying with age) in hepatomegaly and splenomegaly. The data are compared to other morbidity studies in subsaharan Africa, in particular one in the nearby Rusizi Plain. The lesser impact of malaria, the higher egg loads, the recent establishment of the focus and possibly parasite strain differences may account for the more apparent and more important schistosomiasis morbidity in the Cohoha focus. It is concluded that morbidity due to S. mansoni infection is better demonstrated by comparing endemic with non-endemic communities than by relating morbidity to egg counts. Individual egg counts are not always a reliable measure for actual pathology, and their use as a discriminative screening tool for treatment may therefore be questioned.

Morbidity from Schistosoma Mansoni in Relation to Intensity of Infection in a Community-Based Study

The morbidity of schistosomiasis mansoni in the Hijaz highlands was investigated in relation to the intensity of infection among a group of 162 patients. Of these, 58.6% showed light infection, 26....

Sonographic studies of schoolchildren in a village endemic for Schistosoma mansoni

Parasitological, clinical, and sonographic examinations were performed on 309 school children in a village endemic for schistosomiasis mansoni. Data from the 255 denying treatment within the previous 2 years were analysed separately. On a single Kato examination 42% were uninfected; the remainder had light (26%), moderate (21%), or heavy (11%) infections with Schistosoma mansoni. Hepatomegaly (53%) and palpable spleens (35%) were common but clinical and parasitological findings often were unrelated. Abdominal sonography also demonstrated a high frequency of hepatomegaly (82%) and splenomegaly (49%). Sonographically determined liver span and spleen size correlated with the egg count. Sonographic lesions of periportal fibrosis of schistosomiasis mansoni with thickening of portal tracts and portal vein walls were frequently present and more common in infected than in uninfected children, and were correlated with the number of S. mansoni ova in the stool. Ultrasonographically detected periportal fibrosis was a reliable measurement of the prevalence and morbidity of schistosomiasis mansoni in this population, and provided very useful information, even when the parasitological and clinical findings were equivocal.

The morbidity of schistosomiasis mansoni in Maniema (Zaire)

The morbidity of schistosomiasis mansoni was assessed in Makundju (population 547; prevalence 96%, mean egg load 791 epg) and Massimelo (pop. 363; prev. 19%, mean egg load 39 epg), 2 similar villages in the forest zone of Maniema, Zaire. The prevalences of other parasites including malaria (holoendemic) were comparable. “Intermittent diarrhoea” (mostly bloody) was a complaint of 55% and 3% of the populations, respectively, “intermittent abdominal pain” of 63% and 25%, and “fatigue” of 33% and 19%. Enlargement of the left liver lobe was present in 45% and 9% of the populations, right lobe hepatomegaly in 32% and 3%, splenomegaly in 29% and 9%. Hepatomegaly and splenomegaly in Makundju were often very impressive, and most frequent in the 6- to 18-year-old group. Anaemia (haematocrit⩽35%) was present in 30% and 9% of males and 36% and 21% of females. Mean length and weight were lower in Makundju for boys aged 11 to 18 years. Ergometric results (Åstrand cyclometer, male adults only) were comparably low in both villages (mean VO 2max. 19·3 and 18·9). Analysis of the data according to egg load within the Makundju community revealed a significant relationship only in the following cases: (i) higher frequencies of diarrhoea, abdominal pain and fatigue in those excreting more than 200 epg compared with those excreting fewer; (ii) left lobe splenomegaly gradually increased with egg load in children under 18; in people over 40 it occurred at a higher frequency in those excreting more than 2000 epg than in those excreting fewer; (iii) right lobe hepatomegaly occurred at a higher frequency in those excreting more than 600 epg than in those excreting fewer in the age groups up to 40, and at a higher frequency in those excreting more than 2000 epg after that age. Congruent, but not statistically significant, observations were made for splenomegaly. It is concluded that schistosomiasis mansoni is a very important public health factor in highly endemic communities such as Makundju, and that inter-population studies may give more evidence of its morbidity than intra-population studies.

Repeated mass treatment of schistosomiasis mansoni: experience in hyperendemic areas of Brazil. I. Parasitological effects and morbidity

The current project, carried out in Viçosa (state of Alagoas, Brazil), sought to assess the impact of repeated mass treatment campaigns (4 times over a period of 5 years) upon the prevalence, egg counts and morbidity of schistosomiasis mansoni. Results were not impressive. Some control seems to have been achieved in zones of the town better-off in terms of sanitation and socio-economic conditions, while in other areas no effect whatsoever of chemotherapy was detected. Neither resistance to the drug (oxamniquine) nor its deterioration could be held responsible, since a short-term follow-up of a group of children personally treated by the authors showed rapid reinfection, after an excellent initial response. This study, complemented by data from an area in Pernambuco and a hospital survey over the period 1978–1984, indicated that morbidity due to schistosomiasis was decreasing, although there was some evidence that other factors may be at least partly responsible for the increasing scarcity of “hepatosplenic” schistosomiasis. Schistosomiasis, a strictly focal problem, thus calls for a targeted approach to control. It is believed that chemotherapy alone will not suffice and that sanitation, vector control and, perhaps, health education are equally essential in areas which remain refractory to mass treatment.

Morbidity of schistosomiasis mansoni in Brazil. Developmental study in an endemic area over a 10-year period

Four cross sectional studies on morbidity of schistosomiasis mansoni were carried out respectively in 1973, 1974, 1979 and 1983 in the Village of Capitão Andrade, District of Itanhomi, State of Minas Gerais, Brazil, through clinical and fecal examination of the population. In addition a comparison was made of the dinamic and infection rate of the snails and the man-water contact between 1973-1974. The present study compares the prevalence of the human infection by S. mansoni and the evolutive pattern of the disease in the area from 1973 to 1983. Besides 190 persons infected with S. mansoni and 134 non-infected, were followed-up during this period. The infection rate was 60.8% among 1,234 persons examined in 1973, decreasing to 36.2% of the 1,269 examined in 1983. However, the intense migration of the population in the area and the specific treatment of 7% of persons by their own decision may be partially responsible for this reduction. Although there was a decrease of more than 50% in the mean egg output of S. mansoni, there was no change in the morbidity of the disease and in the proportion of the different clinical forms. The incidence of S. mansoni infection among 134 persons followed-up during the ten years was 40.3% (annual average of 4%), with 61.9% in males. The incidence of the clinical forms was 51.8% for type I (intestinal form), 38.9% for type II (hepatointestinal) and 9.3% for type III (hepatoesplenic). The clinical evolutive pattern of 190 patients followed-up during the mentioned period showed that 75.3% had no change, 12.1% deteriorated and 12.6% improved. Two thirds of those which improved (8.4%) had received specific treatment.

Morbidity in Schistosomiasis Mansoni in Relation to Intensity of Infection: Study of a Community in Kisumu, Kenya *

Abstract A random household sample of 30% of the population of 1,393 of Nduru, Kisumu, Kenya was examined in a cross-sectional study of the correlation of morbidity with the prevalence and intensity of schistosomiasis mansoni as determined by standard medical examination. The 384 individuals in 66 households studied had a male:female ratio of 45:55 and an age structure in which more than 50% were below age 20. Malaria was holoendemic in the area, with a spleen rate equal to or greater than Hackett 2 in 34% of individuals without schistosomiasis. S. mansoni infection, as determined by quantitative Kato thick smears, had an overall prevalence of 47% with a peak of 75% in the 40- to 49-year age group. With respect to intensity, 53% were uninfected, 26% had light (10–100 eggs/g), 15% moderate (101–400), and 6% heavy (greater than 401) infections. Peak intensity occurred in females at ages 20–24 years (236 eggs/g) and in males at ages 30–39 (453 eggs/g). A history of not feeling well enough to carry out usual activities occurred in about ⅓ to ½ of the population but was not correlated with presence or intensity of infection. Abdominal pain was reported more frequently by heavily infected individuals. Hepatomegaly was less prevalent in those more heavily infected. Splenomegaly, which occurred in 34% of the uninfected population, was seen in only 5% of those with egg counts greater than 400/g. The methodology of this study of a rural fishing community (Kisumu District) of Nilotic extraction in an area holoendemic for malaria and with schistosomiasis of moderate prevalence and intensity was virtually identical to that of a previous study of a rural farming community (Machakos District) of Bantu extraction in which malaria was rare and schistosomiasis was of high prevalence and intensity. The results in these two communities are compared.

Morbidity in Schistosomiasis mansoni in relation to intensity of infection: study of a community in Machakos, Kenya.

Abstract A random household sample of 30% of the population of 1,393 of Nduru, Kisumu, Kenya was examined in a cross-sectional study of the correlation of morbidity with the prevalence and intensity of schistosomiasis mansoni as determined by standard medical examination. The 384 individuals in 66 households studied had a male:female ratio of 45:55 and an age structure in which more than 50% were below age 20. Malaria was holoendemic in the area, with a spleen rate equal to or greater than Hackett 2 in 34% of individuals without schistosomiasis. S. mansoni infection, as determined by quantitative Kato thick smears, had an overall prevalence of 47% with a peak of 75% in the 40- to 49-year age group. With respect to intensity, 53% were uninfected, 26% had light (10–100 eggs/g), 15% moderate (101–400), and 6% heavy (greater than 401) infections. Peak intensity occurred in females at ages 20–24 years (236 eggs/g) and in males at ages 30–39 (453 eggs/g). A history of not feeling well enough to carry out usual activities occurred in about ⅓ to ½ of the population but was not correlated with presence or intensity of infection. Abdominal pain was reported more frequently by heavily infected individuals. Hepatomegaly was less prevalent in those more heavily infected. Splenomegaly, which occurred in 34% of the uninfected population, was seen in only 5% of those with egg counts greater than 400/g. The methodology of this study of a rural fishing community (Kisumu District) of Nilotic extraction in an area holoendemic for malaria and with schistosomiasis of moderate prevalence and intensity was virtually identical to that of a previous study of a rural farming community (Machakos District) of Bantu extraction in which malaria was rare and schistosomiasis was of high prevalence and intensity. The results in these two communities are compared.

Levantamentos seccionais sôbre a esquistossomose no Nordeste do Brasil: III - Estado de Pernambuco (Município de São Lourenço da Mata)

Os autores apresentam os resultados de levantamentos seccionais sôbre a prevalência e a morbidade da esquistossomose mansônica nas zonas rural e urbana do município de São Lourenço da Mata. A prevalência da esquistossomose e de outras helmintoses foi muito elevada. As formas hepato-esplénicas variaram de 1 a 2 %.

Levantamentos seccionais sobre a esquistossomose no Nordeste do Brasil: II. Estado do Rio Grande do Norte

Os autores apresentam os resultados de levantamentos seccionais sóbre a prevalência e a mortndade da esquistossomose mansônica no Estado do Rio Grande do Norte. Os levantamentos foram, feitos em 44 localidades, urbanas e rurais. A prevalência da esquistossomose e de outras helmintoses intestinais foi muito variável. As formas hépato-esplênicas da esquistossomose variaram de 0 a 4%.