Schistosomiasis In Brazil Research Articles

Identification and characterization of microRNAs in Biomphalaria tenagophila and comparative analysis of their expression in Schistosoma mansoni-resistant and -susceptible snail populations

BackgroundSchistosomiasis is a neglected tropical disease caused by Schistosoma and affects over 240 million people worldwide. One of the most prominent causative agents is Schistosoma mansoni, which develops inside the intermediate host. Biomphalaria tenagophila is the second most important vector of schistosomiasis in Brazil and the Taim population is completely resistant to infection by S. mansoni. ObjectiveThis study aims to identify and characterize B. tenagophila microRNAs (miRNAs) and evaluate their differential expression in S. mansoni-susceptible and -resistant populations of B. tenagophila. MethodsTwo populations of B. tenagophila snails, susceptible and resistant to S. mansoni infection, were used to investigate the small RNA response of these snails after being infected with the parasite. Small RNA sequencing and quantitative real-time PCR were employed to identify and validate differentially expressed miRNAs. Bioinformatics analysis were performed to identify miRNA precursors and mature and evaluate their differential expression. FindingsThe study predicted 173 mature miRNAs and 123 precursors. Among them were six Lophotrochozoa-specific miRNAs, three mollusk-specific miRNAs, and six pre-miRNAs in a cluster. The small RNA sequencing and RT-PCR of B. tenagophila samples allowed assessing the expression patterns of miRNAs. Main conclusionsThe results obtained may support future studies in Biomphalaria spp., generating a global impact on disease control.

Epidemiology of schistosomiasis in Brazil: a retrospective study

Epidemiology of schistosomiasis in Brazil: a retrospective study

Impact of the COVID-19 pandemic on the actions of the Schistosomiasis Control Program in an endemic area in Northeastern Brazil

Schistosomiasis remains a serious public health concern in Brazil and the Schistosomiasis Control Program (PCE) was elaborated to assist in the control of the disease. Nevertheless, the irruption of the COVID-19 pandemic may have impacted the program. Herein, we assessed the impact of the pandemic on PCE actions in an endemic area in the region with the highest positivity rate for schistosomiasis in Brazil. We conducted an ecological, population-based study using data from the PCE of the state of Alagoas, between 2015 and 2021, to calculate the percentage of change. The temporal trend analysis was performed using the segmented log-linear regression model. To evaluate the spatial distribution of the data, choropleth maps were made showing the values of the% of change. Moran maps was elaborated to indicate the critical areas. Our analysis showed a decrease in the population surveyed in 2020 (-41.00%) and 2021 (-18.42%). Likewise, there was a reduction in the number of Kato-Katz tests performed (2020 = -43.45%; and in 2021 = -19.63%) and, consequently, a drop in the rate of positive tests (-37.98% in 2020 and -26.14% in 2021). Importantly, treatment of positive cases was lower than 80% (77.44% in 2020 and 77.38% in 2021). Additionally, spatial clusters with negative percentage values of up to -100% of the PCE indicators were identified mostly in the municipalities of the coastal areas that are historically most affected by schistosomiasis. Taken together, our analyzes corroborate that PCE actions in endemic municipalities of Alagoas were impacted by the COVID-19 pandemic.

Effect of Bauhinia monandra Kurz Leaf Preparations on Embryonic Stages and Adult Snails of Biomphalaria glabrata (Say, 1818), Schistosoma mansoni Cercariae and Toxicity in Artemia salina.

Biomphalaria glabrata snails constitute the main vector of schistosomiasis in Brazil, and Bauhinia monandra Kurz, the leaves of which contain BmoLL lectin with biocidal action, is a plant widely found on continents in which the disease is endemic. This work describes the composition of B. monandra preparations and the effect on embryos and adult snails, their reproduction parameters and hemocytes. We also describe the results of a comet assay after B. glabrata exposure to sublethal concentrations of the preparations. Additionally, the effects of the preparations on S. mansoni cercariae and environmental monitoring with Artemia salina are described. In the chemical evaluation, cinnamic, flavonoid and saponin derivatives were detected in the two preparations assessed, namely the saline extract and the fraction. Both preparations were toxic to embryos in the blastula, gastrula, trochophore, veliger and hippo stages (LC50 of 0.042 and 0.0478; 0.0417 and 0.0419; 0.0897 and 0.1582; 0.3734 and 0.0974; 0.397 and 0.0970 mg/mL, respectively) and to adult snails (LC50 of 6.6 and 0.87 mg/mL, respectively), which were reproductively affected with decreased egg deposition. In blood cell analysis, characteristic cells for apoptosis, micronucleus and binucleation were detected, while for comet analysis, different degrees of nuclear damage were detected. The fraction was able to cause total mortality of the cercariae and did not present environmental toxicity. Therefore, B. monandra preparations are promising in combating schistosomiasis since they can control both the intermediate host and eliminate the infectious agent, besides being safe to the environment.

Epidemiological analysis of Schistosomiasis Mansoni in Brazilian regions

Objective: To analyze the reported cases and the prevalence of schistosomiasis in Brazil, from 2007 to 2017. Methodology: This is an ecological study, using the Database of the Disease and Notification Information System (SINAN) and the Brazilian Institute of Geography and Statistics (IBGE). The variables sex, age group, race/color and education per region and year of notification were selected. Furthermore, the prevalence of each variable was calculated, per 100 000 inhabitants, in order to perform the Prais-Winsten regression, Generalized Least Squares and Odds Ratio. Results: In total, 144 755 cases were reported in non-endemic areas of Brazil, from 2007 to 2017. Most records were found in the Southeast (n=96 411) and Northeast (n=45 774) regions; in males (n=87 149); adults aged 20 to 39 years (n=58 347); brown (n=71 843); and incomplete 1st to 4th grade (n=23 060). The trends showed a decline in the analyzed variables, except for the regions of notification and education. As for the odds ratio, the categories female gender, age group from 20 to 39 years old, brown color/race and level of education from the 5th to the 8th grade were identified as vulnerable to the disease. Conclusions: The analyzes showed that the schistosomiasis scenario in Brazil is still a concern, and that improvements are needed in towards public policies and disease control in non-endemic areas.

Population-based, spatiotemporal modeling of social risk factors and mortality from schistosomiasis in Brazil between 1999 and 2018

Schistosomiasis remains a significant public health concern in Brazil. To identify areas at, and social determinants of health (SDH) associated with, high-risk for schistosomiasis-related mortality from Brazil, we conducted a spatial and spatiotemporal modeling assessing all deaths confirmed in Brazil between 1999 and 2018. We used the segmented log-linear regression model to assess temporal trends, and the local empirical Bayesian estimator, the Global and Local Moran Index for spatial analysis. A total of 12,251 schistosomiasis-related deaths were reported in this period. Within the Mortality Information System (SIM) of the Brazilian Ministry of Health, the states of Alagoas (AL), Pernambuco (PE) and Sergipe (SE) recording the highest mortality rates: 2.21, 1.92 and 0.80 deaths/100,000 inhabitants, respectively. Analyses revealed an increase in the mean age of schistosomiasis-related deaths over the time assessed (APC = 0.9; p-value<0.05). Spatial analysis identified a concentration of municipalities presenting high risk of schistosomiasis-related mortality along the coastline of PE and AL. Similarly, we identified the formation of high space-time clusters in municipalities in the states of PE, AL, SE, Bahia, and Minas Gerais. Finally, mortality rates showed a significant correlation with 96.96% of SDH indices. The data reveal additional important changes in schistosomiasis-related deaths in Brazil between 1999 and 2018, such as a slow reduction among males (unlike females that displayed no change). Regardless, our analyses indicates that schistosomiasis continues to have the greatest detrimental impact in poor regions of Brazil and suggest the need for enhancement of current control measures to accelerate progress.

Burden of schistosomiasis‐related mortality in Brazil: epidemiological patterns and spatial–temporal distribution, 2003–2018

To characterise the epidemiological patterns and the spatial-temporal distribution of schistosomiasis-related mortality in Brazil from 2003 to 2018. A national population-based ecological study that used official data from the Mortality Information System. The data included all deaths recorded in Brazil from 2003 to 2018 in which schistosomiasis was mentioned in the death certificate as an underlying or associated cause of death (multiple causes). The municipalities of residence were used as units of geographic analysis, and standardised and smoothed mortality rates (per 100000 inhabitants) were calculated using the local empirical Bayes method. Spatial autocorrelation was evaluated using global and local Moran indexes. To analyse the spatial dependence, the Getis-Ord G and Gi* statistics were used. During the study period, 18421113 deaths were recorded in Brazil. Schistosomiasis was mentioned in 11487 deaths (proportional mortality: 0.06%); for 8141 deaths (70.87%), it was listed as the underlying cause, and for 3346 deaths (29.13%), it was listed as an associated cause. The mean mortality rate was 0.38 deaths/100000 inhabitants. Individuals≥70years of age (RR: 115.34, 95% CI: 68.56-194.03) and residents in the Northeast region (RR: 10.81, 95% CI: 5.95-19.66) presented higher risks related to schistosomiasis. Municipalities with high mortality rates were identified in all regions, and high-risk clusters were found in municipalities located in the Northeast and Southeast regions of the country. Schistosomiasis remains an important cause of death in persistently endemic areas in Brazil, particularly in those with a high prevalence of the disease and a marked parasite load.

The influence of the age-period-cohort effects on the temporal trend mortality from schistosomiasis in Brazil from 1980 to 2014.

Schistosomiasis is highly debilitating and related to poverty, leading to chronic health problems. This disease is important for public health due to the high prevalence, severity of clinical forms and heterogeneous spatial and temporal patterns. In Brazil, about 1.5 million people are at risk of infection with Schistosoma mansoni, with an annual average of 500 deaths. In this study, the temporal change in mortality was evaluated in relation to the effects of age, period and birth cohort, in Brazil and regions, from 1980 to 2014. In this study, we analyzed the influence of age, period and birth cohort (APC effects) on the temporal evolution of schistosomiasis mortality in Brazil from 1980 to 2014, according to sex and geographic regions of the country. The death records were extracted from the SIM (Mortality Information System) of the DATASUS website (Department of National Health Informatics) of the Ministry of Health of Brazil. The temporal effects were estimated using Bayesian models and the INLA (Integrated Nested Laplace Approximations) method for parameter inference. More than 24 thousand deaths were registered in the analyzed period, mainly in men from the Northeast region. In Brazil, children under 14 years of age had protection against death from schistosomiasis. There was no significant effect for others ages. From 1990 to 1999, there was a protective effect for death from schistosomiasis and a null effect in the other periods. There was a decreasing trend in the risk of death among birth cohorts. The greatest risk was among people born from 1903 to 1912. There was a protective effect for death among people born after 1968. Men were at risk of death between 25 and 54 years old, while women were at risk after seventy years of age. The southern and central-western regions had a risk of death until 1989 and had a protective effect between1995 and 1999. The northern region had a risk of death between 1985 and 1994, and a protective effect after 2005. The northeast and Southeast regions had protective effects for death between the years 1990 and 1999, and after 2000, respectively. People born until 1952 and 1957 were at risk of dying in the South and North regions, respectively, and a protective effect among people born after 1968, in both regions. In the Northeast region, there was a protective effect among people born after 1963. In the other regions, there was a risk of death among people born until 1962 and a protective effect among people born after 1973. The Central-West region had the least declining trend in risk of death among birth cohorts. The birth cohorts had a great influence on the decreasing trend of schistosomiasis mortality in Brazil. This result may be due to the interaction between demographic changes and greater access to health and sanitation services, in addition to the impact of schistosomiasis control measures experienced by younger cohorts.

Spatial and Seasonal Distribution of Holochilus sciureus with Schistosoma mansoni Infection in an Endemic Area for Schistosomiasis in Brazil.

The occurrence of wild rodents in the Schistosoma mansoni life cycle may increase the transmission of schistosomiasis and understanding the spatial and seasonal distribution of the natural infection of these reservoirs is essential for the development of more effective control strategies. In this study, Holochilus sciureus rodents were captured from the flooded fields of São Bento city (an endemic area for schistosomiasis in Northeast Brazil), during the dry and rainy seasons. All these sites were georeferenced and the prevalence of S. mansoni was verified by the presence of adult worms in the mesenteric branches and livers of each animal. It was demonstrated that almost half of the animals collected were naturally infected with S. mansoni (45.45%) and this infection was not related to the distance from urban areas. Furthermore, the temperature, precipitation, sex, and weight did not interfere with the H. sciureus infection rates. Interestingly, we found, for the first time, the natural infection of H. sciureus in another endemic city of S. mansoni in Northeast Brazil. Therefore, the H. sciureus rodent shows a high natural infection rate for S. mansoni in the flooded fields of São Bento, regardless of the weather station, capture distance, and biological aspects. Additionally, we have demonstrated that H. sciureus naturally parasitized with S. mansoni may inhabit a much more extensive area that is currently described in the literature.

The cost of a disease targeted for elimination in Brazil: the case of schistosomiasis mansoni.

BACKGROUND Schistosomiasis mansoni is a poverty-related parasitic infection that has a variety of clinical manifestations. We consider the disability and deaths caused by schistosomiasis unacceptable for a tool-ready disease. Its condition in Brazil warrants an analysis that will enable better understanding of the local health losses and contribute to the complex decision-making process.OBJECTIVE This study estimates the cost of schistosomiasis in Brazil in 2015.METHODS We conducted a cost of illness study of schistosomiasis mansoni in Brazil in 2015 based on a prevalence approach and from a societal perspective. The study included 26,499 schistosomiasis carriers, 397 hepatosplenic cases, 48 cases with the neurological form, 284 hospitalisations, and 11,368.26 years of life lost (YLL) of which 5,187 years are attributable to economically active age groups.RESULTS The total cost of schistosomiasis mansoni in Brazil was estimated to be US$ 41,7million in 2015 with 94.61% of this being indirect costs.CONCLUSIONS The economic burden of schistosomiasis mansoni in Brazil is high and results in the loss of productivity. Its persistence in Brazil is a challenge to public health and requires inter-sectorial interventions in areas such as indoor water supply, basic sanitation, and education.

Prevalence of Infection of Biomphalaria glabrata by Schistosoma mansoni and the risk of urban Schistosomiasis mansoni in Salvador, Bahia, Brazil.

Biomphalaria glabrata is considered to be responsible for the incidence of schistosomiasis in Brazil. Therefore, surveillance of areas where schistosomiasis is prevalent is fundamental for public health planning. This study was aimed to evaluate B. glabrata populations in water bodies of the city of Salvador, determine their distribution, estimate the prevalence of Schistosoma mansoni infections, characterize shed cercariae, and identify transmission foci. Malacological surveys were carried out in 17 water collections from Salvador. Snail species were identified based on shell and mantle characteristics. Snails were evaluated for S. mansoni infection by exposure to light and via real time polymerase chain reaction (qPCR) using S. mansoni-18S rRNA subunit specific primers. 1,403 B. glabrata were collected. Classical cercarial shedding indicated that 5 snails (0.4%) were positive for S. mansoni. A higher prevalence of infections was found in Horta de Saramandaia (5.5%) and Lagoa do IAT (1.9%). Non-Schistosoma larvae, such as Xiphidiocercaria, Strigeidae, Spirorchiidae and Clinostomidae, were observed in 3.2% of the snails. S. mansoni DNA was detected in 6.2% snails via qPCR. B. glabrata is widely distributed in Salvador, as indicated by 7 water collections associated with a risk of schistosomiasis transmission. To our knowledge, this is the first study to identify B. glabrata eliminating cercariae of Clinostomidae, Strigeidae, and Spirorchiidae in Salvador. We propose that qPCR may be employed in combination with classical cercarial shedding. Estimating S. mansoni prevalence in snails by only considering the results of light exposure method classical into account may underestimate the problem.

Thrombocytopenia as a marker of liver steatosis in a low-endemic area for schistosomiasis mansoni.

Thrombocytopenia is commonly found in patients living in highly endemic areas for Schistosoma mansoni. Recently, different degrees of liver steatosis have also been associated with low platelet counts worldwide. We investigated the association of platelet counts with hepatosplenic schistosomiasis and with liver steatosis in an area of low prevalence of schistosomiasis in Brazil. Pains, a city in the state of Minas Gerais, Brazil, had a population of 8,307 inhabitants and a schistosomiasis prevalence of 8%. Four micro-areas comprising 1,045 inhabitants were selected for this study. Blood sample was collected and a complete blood count (CBC) was performed. Eighty-seven (87) patients had low platelet counts (group 1 - 8.3%) and 94 volunteers presenting normal CBC were randomized (group 2 - 8.9%). They underwent clinical and ultrasound examinations. Liver steatosis was determined as either present or absent using abdominal ultrasound. A spleen > 12 cm in length, measured by ultrasound (US), was considered to be increased. Data collected were analyzed using SPSS software version 19.0. Twenty-two patients (22/25.3%) in group 1 had liver steatosis compared with 11 volunteers (11.7%) in group 2 (p=0.02). Hepatosplenic schistosomiasis was diagnosed in two patients (p>0.05). Thrombocytopenia was not a good marker of hepatosplenic schistosomiasis mansoni in a low prevalence area in Brazil. Liver steatosis was associated with thrombocytopenia in our study.

The Pseudotumoral Form of Schistosomiasis mansoni, intestinal and peritoneal, reported in 108 years of publications on Schistosomiasis in Brazil and Abroad.

The Pseudotumoral Form of Schistosomiasis mansoni, intestinal and peritoneal, reported in 108 years of publications on Schistosomiasis in Brazil and Abroad.

Ultrastructural characterization of cells in primary cultures from different adult tissues of Biomphalaria tenagophila TAIM, a strain that is absolutely resistant to Schistosoma mansoni infection

The etiological agent of schistosomiasis in Brazil, Schistosoma mansoni, requires an obligatory passage through Biomphalaria snails to complete its life cycle. In these intermediate hosts, interaction with the parasite is mediated by humoral factors and hemocytes by mechanisms that are not yet fully understood. Extant studies exploring these processes are usually conducted through experimental infection of Biomphalaria with S. mansoni miracidia. Thus, tissue-derived cultures of Biomphalaria may be useful in increasing the understanding of that interaction at cellular level. However, in the absence of morphological characterization of those cells in culture, the application of such models is delayed. In the present work, we cultured different tissues of B. tenagophila, the second most important host of S. mansoni in Brazil, using a strain that is naturally and absolutely resistant to S. mansoni infection. This decision was driven by the view that this strain might be provided with the most effective response against parasite infection. Primary cultures were successfully established from nine Biomphalaria tissues and the respective cells in culture were ultra structurally described. Attention was particularly devoted to cells derived from mantle cavity and kidney tissues. Although they have been considered important centers for hemocyte production in Biomphalaria, no detailed cell characterization is available in the pertinent literature. Herein, kidney-derived cells partially shared hematoblast characteristics. Moreover, under optical microscopy, kidney cells in culture were very similar to those derived from amebocyte-producing organ (APO) cultures, which have been recently shown to be capable of eliminating S. mansoni sporocysts in vitro. Based on the close resemblance of those cultures and their anatomical proximity inside the mantle cavity, we suggest the effective participation of Biomphalaria kidney cells in hematopoiesis and in host response to S. mansoni infection.

Predictive risk mapping of schistosomiasis in Brazil using Bayesian geostatistical models

Schistosomiasis is one of the most common parasitic diseases in tropical and subtropical areas, including Brazil. A national control programme was initiated in Brazil in the mid-1970s and proved successful in terms of morbidity control, as the number of cases with hepato-splenic involvement was reduced significantly. To consolidate control and move towards elimination, there is a need for reliable maps on the spatial distribution of schistosomiasis, so that interventions can target communities at highest risk. The purpose of this study was to map the distribution of Schistosoma mansoni in Brazil. We utilized readily available prevalence data from the national schistosomiasis control programme for the years 2005–2009, derived remotely sensed climatic and environmental data and obtained socioeconomic data from various sources. Data were collated into a geographical information system and Bayesian geostatistical models were developed. Model-based maps identified important risk factors related to the transmission of S. mansoni and confirmed that environmental variables are closely associated with indices of poverty. Our smoothed predictive risk map, including uncertainty, highlights priority areas for intervention, namely the northern parts of North and Southeast regions and the eastern part of Northeast region. Our predictive risk map provides a useful tool for to strengthen existing surveillance-response mechanisms.

The Pampulha reservoir remains a potential urban focus of schistosomiasis mansoni in Brazil: changes in the occurrence patterns of Biomphalaria species and a new record of the parasite

The Pampulha reservoir has long been a focus of schistosomiasis transmission in Belo Horizonte, State of Minas Gerais, Brazil. The last malacological study conducted in this urban reservoir was more than two decades ago, and thus, an update on the distribution of the species of Biomphalaria as well as new data on the presence of Schistosoma mansoni in this water body are required. The current distribution of Biomphalaria spp. in the Pampulha reservoir and their infection with S. mansoni was evaluated during 55 malacological surveys conducted between 2009 and 2012. Biomphalaria straminea displayed a high population density and distribution, and 13.7% (2,233/16,235) of the specimens collected were infected with larval trematodes other than Schistosoma mansoni. Biomphalaria tenagophila and Biomphalaria glabrata, species currently presenting a restricted distribution and small populations, displayed trematode infection rates of 15.2% (98/644) and 13% (83/640), respectively. Thirteen (2%) specimens of B. glabrata were found to be infected with S. mansoni. In addition, a historical review based on previous and new data on the occurrence patterns of Biomphalaria species in this reservoir is presented. The results indicate that the Pampulha reservoir remains a potential focus of urban schistosomiasis in Brazil, and significant changes in the occurrence patterns of Biomphalaria species were verified.

Glomerulonephritis in schistosomiasis mansoni: a time to reappraise

The current prevalence of glomerulonephritis in patients with hepatosplenic schistosomiasis mansoni in Brazil was evaluated. Sixty three patients (mean age 45.5 ± 11 years) attending the outpatient infectious disease clinic of a University Hospital in Belo Horizonte, Brazil, from 2007 to 2009, were consecutively examined and enrolled in the present investigation. Diagnosis of hepatosplenic schistosomiasis was based on epidemiological, clinical and parasitological data and imaging techniques. Eight patients, who presented >30 mg/day albuminuria, were submitted to percutaneous ultrasound guided renal biopsy. Kidney tissue fragments were examined under light, direct immunofluorescence and electron microscopy. All patients showed mesangial enlargement. In five, mesangial hypercellularity was observed and four presented duplication of the glomerular basement membrane. Areas of glomerular sclerosis were diagnosed in four. Deposits of immunoglobulin M and C3 were present in six samples; deposits of IgG in four, IgA in three and C1q in two samples. In all patients, immunoglobulin A was reported in the lumen of renal tubules. Deposits of kappa and lambda were observed in six samples. Electron microscopy revealed dense deposits in the glomerular tissue of three patients. Arterial hypertension, small esophageal varices, slight increases in serum creatinine and decreases in serum albumin were associated with glomerular disease. Renal disease associated with hepatosplenic schistosomiasis was verified in 12.7% of patients and type I membranoproliferative glomerulonephritis was observed in 50% of them. Schistosomal glomerulopathy still is an important problem in patients with hepatosplenic schistosomiasis in Brazil.

The role of population movement in the epidemiology and control of schistosomiasis in Brazil: a preliminary typology of population movement

This paper examines recent developments in migration studies. It reviews literature related to the potential role of internal population movement in the occurrence of schistosomiasis in Brazil and modifies Prothero's typology of population movement for use in Brazil. This modified classification system may contribute to a better understanding of schistosome transmission as well as improved research and control programs. The results of this study indicate that population movement in Brazil primarily involves economically-motivated rural-urban and interregional movement. However, several movement patterns have become increasingly important in recent years as a result of changing socioeconomic and urbanisation dynamics. These patterns include urban-urban, intracity and urban-rural movement as well as the movement of environmental refugees and tourists. Little is known about the epidemiological significance of these patterns. This paper also highlights the role of social networks in the decision to migrate and to settle. Prothero's classic population movement typology categorises movement as either one-way migrations or circulations and examines them along spatial and temporal scales. However, the typology must be modified as epidemiological information about new patterns becomes available. This paper identifies areas that require further research and offers recommendations that can improve the measurement and spatial analysis of the relationship between population movement and schistosomiasis.

Serum hyaluronan and collagen IV as non-invasive markers of liver fibrosis in patients from an endemic area for schistosomiasis mansoni: a field-based study in Brazil

Non-invasive markers of fibrosis have been used to diagnose liver fibrosis in a variety of diseases. Hyaluronic acid (HA) and collagen IV (C-IV) levels were measured in the sera of patients from an endemic area for schistosomiasis in Brazil to diagnose and to rank the intensity of liver fibrosis. Seventy-nine adult patients with schistosomiasis, in the age range of 21-82 years (49 +/- 13.4) were submitted to clinical and ultrasonographic examinations. Ultrasound was employed to diagnose and categorise liver fibrosis according to World Health Organization patterns. Serum HA and C-IV levels were measured using commercial ELISA kits. Ultrasound revealed six patients with intense liver fibrosis, 21 with moderate, 23 with light and 29 without. Serum HA was able to separate individuals with fibrosis from those without (p < 0.001) and light from intense fibrosis (p = 0.029), but C-IV was not (p = 0.692). The HA diagnostic accuracy for fibrosis was 0.89. The 115.4 ng/mL cut-off level diagnosed patients with fibrosis (sensitivity 0.98, specificity 0.64). HA correlated positively with portal hypertension. Periportal fibrosis (subjective evaluation), age and collateral circulation predicted HA increase. In conclusion, we propose that serum HA can be used to identify patients with liver fibrosis in an endemic area for schistosomiasis mansoni in Brazil.

Comparison between clinical and ultrasonographic findings in cases of periportal fibrosis in an endemic area for schistosomiasis mansoni in Brazil

Abdominal palpation and ultrasound findings among patients from an endemic area for schistosomiasis in Brazil who had been followed up for 27 years were compared. In 2004, 411 patients from Brejo do Espírito Santo, in the State of Bahia, were selected for the present investigation after giving their written informed consent. Based on clinical data, they were divided into three groups: 41 patients with evidence of liver fibrosis in 2004 (Group 1); 102 patients with evidence of liver fibrosis in the past (1976-1989) but not in 2004 (Group 2); and 268 patients without evidence of liver fibrosis at any time during the 27-year follow-up (Group 3). All of the patients underwent abdominal ultrasound in which the examiner did not know the result from the clinical examination. The data were stored in a database. The prevalence of periportal fibrosis on ultrasound was 82.9%, 56.9% and 13.4% in Groups 1, 2 and 3, respectively. In the presence of hard, nodular liver or prominent left lobe and a hard palpable spleen, ultrasound revealed periportal fibrosis in 70.9%. However, periportal fibrosis was diagnosed using ultrasound in 25.4% of the patients in the absence of clinical evidence of liver involvement. Thus, ultrasound diagnosed periportal fibrosis 3.1 times more frequently than clinical examination did. Although clinical examination is important in evaluating morbidity due to Manson's schistosomiasis in endemic areas, ultrasound is more accurate in diagnosing liver involvement and periportal fibrosis.