Schistosomiasis Mansoni Research Articles

Prevalence of human Schistosoma mansoni infection in endemic regions (2010–2024): a systematic review and meta-analysis

Schistosoma mansoni infection poses a substantial public health challenge globally, and the World Health Organization (WHO) aims for the elimination of schistosomiasis by 2030. This study aimed to assess the current prevalence of human S.mansoni infection in endemic regions worldwide between 2010 and2024. We conducted a comprehensive search in PubMed/Medline and Scopus databases as well as other public sources from 1 January 2010 to 15 July 2024. Population-based studies reporting the prevalence of S.mansoni infection were eligible. We undertook a random-effects meta-analysis to estimate pooled prevalences with 95% confidence intervals (CIs) in WHO-defined regions and assessed potential risk factors associated with S.mansoni infection. The protocol for this study was registered on PROSPERO (CRD42023438455). We identified a total of 542 eligible studies involving 1,163,866 individuals who had been tested for S.mansoni infection in 38 countries. The overall, pooled global prevalence of S.mansoni infection in endemic region was 14.8% (95% CI, 13.5%-16.1%). The pooled prevalences (95% CI) in specific regions were: 15.3% (13.9-16.8%) in sub-Saharan Africa, 12.4% (8.9-16.4%) in South America and 9.5% (5.4-14.6%) in the Eastern Mediterranean region. There was a 52.6% decrease in prevalence of S.mansoni infection and a 37% decrease in high-intensity infection for studies conducted between 2010 and 2014 compared to those conducted between 2020 and 2023. The present analysis revealed that factors including male gender, bathing or swimming in natural water bodies, crossing rivers or lakes, and engaging in water irrigation activities such as fishing, working in rice paddies or maintaining irrigation canals were significantly associated with S.mansoni infection. The findings of this investigation revealed that, despite a decline in prevalence and high-intensity infection, 7-12% of people in endemic regions, notably in sub-Saharan Africa, remained affected by schistosomiasis mansoni between 2020 and 2024. This study provides data of relevance to policymakers to support efforts to eliminate this disease. This study received no funding.

A Recent Advance in the Diagnosis, Treatment, and Vaccine Development for Human Schistosomiasis.

Schistosomiasis, which affects a large number of people worldwide, is among the most overlooked parasitic diseases. The disease is mainly prevalent in sub-Saharan Africa, southeast Asian countries, and South America due to the lack of adequate sanitation. The disease is mainly associated with poor hygiene, sanitation, and contaminated water, so it is also known as a disease of poverty. Three Schistosoma species (S. mansoni, S. japonicum, and S. haematobium) cause significant human infections. Co-infections with Schistosoma and other parasites are widely common. All these parasites may cause intestinal or urogenital schistosomiasis, where the disease may be categorized into the acute, sensitized, and chronic phases. The disease is more prevalent among school children, which may cause anemia and reduce development. Chronic infections frequently cause significant liver, intestinal, and bladder damage. Women exposed to contaminated water while performing normal duties like washing clothes might acquire urogenital schistosomiasis (UGS), which can cause tissue damage and raise the risk of blood-borne disease transmission, including human immunodeficiency virus (HIV) transmission. Praziquantel (PZQ) is the World Health Organization (WHO)-prescribed treatment for individuals who are known to be infected, but it does not prevent further re-infections with larval worms. Vaccine development and new molecular-based diagnosis techniques have promised to be a reliable approach to the diagnosis and prevention of schistosomiasis. The current review emphasizes the recent advancement in the diagnosis of schistosomiasis by molecular techniques and the treatment of schistosomiasis by combined and alternative regimes of drugs. Moreover, this review has also focused on the recent outbreak of schistosomiasis, the development of vaccines, and their clinical trials.

Molecular epidemiology and population genetics of Schistosoma mansoni infecting school-aged children situated along the southern shoreline of Lake Malawi, Malawi.

In areas of low disease endemicity, highly sensitive diagnostic tools to identify, diagnose, and monitor intestinal schistosomiasis transmission are needed to reliably measure the burden and risk of infection. Here, we used highly sensitive molecular diagnostic methods to investigate Schistosoma mansoni prevalence and transmission along the southern shoreline of Lake Malawi, five years post-disease outbreak. Faecal and urine samples were provided by school-aged children situated along the southern shoreline of Lake Malawi. Kato-Katz faecal-egg microscopy and point-of-care circulating cathodic antigen (POC-CCA) rapid diagnostic tests were then performed to diagnose infection with S. mansoni. Urine-egg microscopy was also used to diagnose infection with Schistosoma haematobium. In addition, Schistosoma miracidia were isolated from faecal material using a standard miracidium hatching technique. A two-step real-time PCR approach was then used to diagnose infection with S. mansoni using DNA isolated from faecal samples. Furthermore, isolated miracidia were genotyped to species level through PCR and Sanger sequencing. Phylogenetic analyses were then carried out to identify which previously defined S. mansoni cox1 lineage group S. mansoni miracidia were most closely related to. The measured prevalence of S. mansoni infection varied considerably depending on which diagnostic assay was used. When compared to real-time PCR, faecal-egg microscopy had a sensitivity of 9% and a specificity of 100%. When POC-CCA 'trace' results were considered positive, POC-CCA had a sensitivity of 73% and a specificity of 81% when compared to real-time PCR. However, when considered negative, POC-CCA sensitivity was reduced to 56%, whereas specificity was increased to 90%. In addition, a high degree of S. haematobium DNA was detected in DNA isolated from faecal samples and motile S. haematobium miracidia were recovered from faecal samples. Schistosoma mansoni miracidia were closely related to two independent cox1 lineage groups, suggesting multiple recent introduction and colonisation events originating from surrounding east African countries. Intestinal schistosomiasis is now highly prevalent along the southern shoreline of Lake Malawi just five years post-disease outbreak. In addition, a high prevalence of urogenital schistosomiasis persists. The revision of ongoing schistosomiasis control programmes in this area is therefore recommended. Our study also highlights the need for reliable diagnostic assays capable of distinguishing between Schistosoma species in multispecies co-endemic areas.

A-250 Evaluation of Liver Fibrosis in Schistosomiasis Mansoni Using the ELF (Enhanced Liver Fibrosis) Score

Abstract Background Measuring the presence and pattern of periportal fibrosis (PPF) in schistosomiasis mansoni (SM) is essential for diagnosing its clinical forms and detection of portal hypertension. For these evaluations, the gold-standard has been ultrasound scan (US) using Niamey classification, however it requires sophisticated equipment and well-trained operator. ELF (Enhanced Liver Fibrosis) is an index capable of quantifying liver fibrosis in chronic liver diseases, although there have been few studies evaluating PPF in SM. Aim To assess serum ELF levels according to the PPF patterns established by ultrasound using the Niamey classification in patients with schistosomiasis. Methods A cross-sectional, bidirectional analytical study was carried out with patients from an endemic area (patterns A, B, C and D) and from an SM reference outpatient clinic (patterns D, E and F). Clinical data and 10 mL of blood were collected, centrifuged and frozen to measure and calculate the score by the ELF™ Test (Atellica® IM), according to the equation: [ELF = 2.278 + 0.851 ln(HA) + 0.751 ln(PIIINP) + 0.394 ln(TIMP-1)] and expressed as a numerical value without unit. US using GE Healthcare Logic E (endemic area) or Siemens Acuson S2000 (outpatient clinic) equipment were performed by a single examiner. Results Of the 196 patients evaluated, 114 (58.2%) were women with a mean age of 45 ± 15.42 years. They had the following PPF patterns: 18 pattern A+B; 64 pattern C; 56 pattern D; 49 pattern E and 9 pattern F. The median ELF values were higher according to PPF progression in these 5 groups (p = 0.0021), respectively: (A+B = 8.36); (C = 8.40); (D = 8.64); (E = 8.99) and (F = 9.75). The ELF was able to differentiate patients without PPF, with mild, moderate and advanced PPF: A+B vs C vs D vs E+F (p = 0.0024), as well as patients with advanced PPF from those without fibrosis or with moderate fibrosis: A+B vs E+F (p = 0.0464) and C+D vs E+F (p = 0.0007). The index was also able to differentiate patients with absent or mild PPF from those with moderate or advanced PPF: A+B+C vs D+E+F (p = 0.0015). Conclusions The ELF showed great potential as a tool for assessing PPF in patients with schistosomiasis mansoni, being able to differentiate those with little fibrosis from those with moderate or advanced fibrosis.

Epidemiology of periportal fibrosis and relevance of current Schistosoma mansoni infection within the context of repeated mass drug administration in rural Uganda: a population-based, cross-sectional study

WHO guidelines for schistosomiasis-related morbidity control and elimination rely on current infection as a proxy indicator for morbidity. We evaluated these guidelines within the context of repeated mass drug administration and periportal fibrosis attributable to chronic intestinal schistosomiasis. We examined 1442households randomly sampled from 38villages in Buliisa, Pakwach, and Mayuge districts of Uganda within the SchistoTrack cohort. Periportal fibrosis was diagnosed in 2834individuals aged 5-90years using ultrasound and image patterns C-F from the Niamey protocol. Schistosoma mansoni status and intensity were diagnosed by Kato-Katz microscopy and point-of-care circulating cathodic antigen tests. Schistosome infection, co-infections, and comorbidities were examined as exposures for periportal fibrosis. Multivariable logistic regressions were run with SEs clustered by household. Between Jan 6and Feb 3, 2022, 342 (12·1%) of 2834 participants were diagnosed with periportal fibrosis. ByKato-Katz microscopy, 1229 (43·4%) of 2834participants were infected. 1863 (65·7%) of 2834participants had trace positive point-of-care circulating cathodic antigen tests, which was higher than prevalence by Kato-Katz microscopy, and 1158 (40·9%) of 2834participants had trace negative point-of-care circulating cathodic antigen tests. Individual schistosome status, intensity, and prevalence of heavy intensity infections of less than 1% and less than 5% were not correlated with periportal fibrosis likelihood or village prevalence. Periportal fibrosis likelihood linearly increased with age from age 5 years to age 25years, non-linearly increased from age 26 years to age 45years, attenuated or remained unchanged from age 46 years to age 60years, and steadily decreased past 60years of age. History of liver diseases, HIV, and ultrasound-detected chronic hepatitis or early cirrhosis-like disease were associated with more than two-times increased periportal fibrosis likelihood. WHO guidelines reliant on current schistosome status and intensity are uninformative for identifying probable cases or communities with periportal fibrosis. History of HIV and underlying chronic hepatitis or early cirrhosis-like disease are risk factors that could be investigated for periportal fibrosis surveillance and management. NDPH Pump Priming Fund, Wellcome Trust, John Fell Fund, Robertson Foundation, and UK Research and Innovation Engineering and Physical Sciences Research Council.

Prevalence of schistosomiasis among school children at Esuekyir community in the Central Region of Ghana

Schistosomiasis, an endemic neglected tropical disease in areas with poor sanitation, causes physical and mental defects in both children and adults. Various strategies, especially drug administration for morbidity control, have been implemented to combat the disease in Ghana and globally. Despite these efforts, schistosomiasis remains prevalent in Ghana, negatively impacting children's academic performance, growth, and overall quality of life. This study aimed to determine the prevalence of schistosomiasis in school children at Esuekyir, a peri-urban community in Ghana. A cross-sectional study using simple random sampling technique to select participants and collect stool and urine samples from 246 school children in Esuekyir was adopted. Microscopy of urine and stool samples was performed involving urine sedimentation and stool formol-ether sedimentation techniques to analyse for parasite eggs. Questionnaires were developed to help detect risk factors that expose these children to the disease. The prevalence of urogenital schistosomiasis in children at Esuekyir was 15.45% while that of intestinal schistosomiasis was 6.957.0%. There was one case of co-infection of urogenital and intestinal schistosomiasis from a 13 year old primary student. Children in primary school had higher risks of infection due to their activities around the water body. There was a significant association between class groups and urogenital schistosomiasis (p-value = 0.042). The presence of schistosomiasis in school children highlights the importance of targeted interventions and public health initiatives in addressing this specific disease condition especially in primary school children. Findings from the research revealed a higher prevalence of urogenital schistosomiasis in the study population as compared to intestinal schistosomiasis.

Immune targets for schistosomiasis control identified by a genome-wide association study of East African snail vectors.

Schistosomiasis, afflicting >260 million people worldwide, could be controlled by preventing infection of freshwater snail vectors. Intestinal schistosomiasis, caused by Schistosoma mansoni, occurs predominantly in Sub-Saharan Africa and is vectored by Biomphalaria sudanica and related Biomphalaria species. Despite their importance in transmission, very little genomic work has been initiated in African snails, thus hindering development of novel control strategies. To identify genetic factors influencing snail resistance to schistosomes, we performed a pooled genome-wide association study (pooled-GWAS) on the offspring of B. sudanica collected from a persistent hotspot of schistosomiasis in Lake Victoria, Kenya, and exposed to sympatric S. mansoni. Results of the pooled-GWAS were used to develop an amplicon panel to validate candidate loci by genotyping individual snails. This validation revealed two previously uncharacterized, evolutionarily dynamic regions, SudRes1 and SudRes2, that were significantly associated with resistance. SudRes1 includes receptor-like protein tyrosine phosphatases and SudRes2 includes a class of leucine-rich repeat-containing G-protein coupled receptors, both comprising diverse extracellular binding domains, suggesting roles in pathogen recognition. No loci previously tied to schistosome resistance in other snail species showed any association with compatibility suggesting that loci involved in the resistance of African vectors differ from those of neotropical vectors. Beyond these two loci, snail ancestry was strongly correlated with schistosome compatibility, indicating the importance of population structure on transmission dynamics and infection risk. These results provide the first detail of the innate immune system of the major schistosome vector, B. sudanica, informing future studies aimed at predicting and manipulating vector competence.

Prevalence and associated factors of schistosomiasis among pregnant women in northern Senegal

BackgroundSchistosomiasis remains a public health concern worldwide. It is responsible for more than 240 million cases in 78 countries, 40 million of whom are women of childbearing age. In the Senegal River basin, both Schistosoma haematobium and Schistosoma mansoni are very prevalent in school-age children. However, there is a lack of information on the burden of schistosomiasis in pregnant women, which can cause complications in the pregnancy outcome. This study aimed to determine the prevalence and associated factors of schistosomiasis in pregnant women.MethodsWe conducted a prospective cross-sectional study of pregnant women attending antenatal clinics at the health center of the Senegalese Sugar Company and at the hospital of Richard Toll between August and December 2021. The urine and stool samples collected were examined using microscopy techniques and quantitative polymerase chain reaction (qPCR) to detect the presence of S. haematobium and S. mansoni. The urines were previously tested using urine reagent strips to detect hematuria and proteinuria. Socio-demographical, clinical, and diagnostically data were recorded by the midwife and the gynaecologist. The data were analyzed using a logistic regression model.ResultsAmong the 298 women examined for the infection by microscopic, 65 (21.81%) were infected with urogenital schistosomiasis, 10 (3.36%) with intestinal schistosomiasis, and 4 (1.34%) were co-infected with both types of schistosomiasis. Out of the 288 samples tested by qPCR, 146 (48.99%) were positive for S. haematobium, 49 (35.51%) for S. mansoni and 22 (15.94%) for both species (co-infection). Pregnant women having microscopic haematuria and proteinuria were significantly more infected (p < 0.05).ConclusionThis study has revealed a high prevalence of schistosomiasis in pregnant women in Senegal. The qPCR allowed us to detect more cases compared to the microscopy. There is a need to conduct more studies to understand the real burden of the disease and to set up a surveillance system to prevent pregnancy-related complications.

Mapping of Village Population Profile with Schistosomiasis Cases Using Clustering Large Applications

Schistosomiasis is a tropical disease caused by Schistosoma mansoni (intestinal schistosomiasis) and Schistosoma haematobium (urogenital schistosomiasis). Schistosomiasis in Indonesia is endemic to Central Sulawesi and is commonly found in the Napu Valley and Bada Valley areas, which are administratively included in Poso District and Sigi District. One approach to obtain information on schistosomiasis endemic areas is by mapping the population profile of villages with schistosomiasis cases. This mapping is intended to provide an overview of the social and demographic conditions of villages with schistosomiasis cases. One of the many analysis methods that can be used is cluster analysis. Cluster analysis is a method for grouping data based on the extent of their similarities. Data with similar characteristics will be grouped together, while data with different characteristics will be placed in different groups. Among several types of methods in cluster analysis is Clustering Large Application (CLARA). CLARA is a clustering method which is more robust to unusual data and can be applied to handle large volumes of data. The results of this study are obtained two optimum clusters, each possessing distinct characteristics as determined by Schistosomiasis cases indicators. Cluster 1 with low schistosomiasis cases and cluster 2 with high schistosomiasis cases.

Efficacy and safety of single-dose artesunate plus sulfalene/pyrimethamine combined with praziquantel for the treatment of children with Schistosoma mansoni or Schistosoma haematobium in western Kenya: a randomised, open-label controlled trial

BackgroundReliance on praziquantel for the treatment and control of schistosomiasis is likely to facilitate the emergence of drug resistance. Combination therapy targeting adult and juvenile schistosome worms is urgently needed to improve praziquantel efficacy and delay the potential development of drug resistance. We assessed the efficacy and safety of single-dose praziquantel combined with single-dose artesunate plus sulfalene-pyrimethamine in the treatment of Kenyan children with schistosomiasis.MethodsThis was an open-label, randomised clinical trial involving 426 school-aged children (7–15 years old) diagnosed with Schistosoma mansoni (by Kato-Katz) or S. haematobium (by urine filtration). They were randomly assigned (1:1:1) to receive a single dose of praziquantel (40 mg/kg), a single dose of artesunate plus sulfalene-pyrimethamine (12 mg/kg artesunate) or combination therapy using a single dose of praziquantel (40 mg/kg) combined with a single dose of artesunate plus sulfalene-pyrimethamine (12 mg/kg artesunate). The primary outcome was cure and egg reduction rates at 6 weeks post-treatment in the available case population. Adverse events were assessed within 3 h after treatment.ResultsOf the 426 children enrolled, 135 received praziquantel, 150 received artesunate plus sulfalene-pyrimethamine, and 141 received combination therapy. Outcome data were available for 348 (81.7%) children. For S. mansoni-infected children (n = 335), the cure rates were 75.6%, 60.7%, and 77.8%, and the egg reduction rates were 80.1%, 85.0%, and 88.4% for praziquantel, artesunate plus sulfalene-pyrimethamine, and combination therapy, respectively. For S. haematobium-infected children (n = 145), the corresponding cure rates were 81.4%, 71.1%, and 82.2%, and the egg reduction rates were 95.6%, 97.1%, and 97.7%, respectively. Seventy-one (16.7%) children reported mild-intensity adverse events. The drugs were well tolerated and no serious adverse events were reported.ConclusionsA single oral dose of praziquantel combined with artesunate plus sulfalene-pyrimethamine cured a high proportion of children with S. haematobium but did not significantly improve the treatment efficacy for either urinary or intestinal schistosomiasis. Sequential administration of praziquantel and artesunate plus sulfalene-pyrimethamine may enhance the efficacy and safety outcomes.Graphical abstract

A geospatial analysis of local intermediate snail host distributions provides insight into schistosomiasis risk within under-sampled areas of southern Lake Malawi

BackgroundAlong the southern shoreline of Lake Malawi, the incidence of schistosomiasis is increasing with snails of the genera Bulinus and Biomphalaria transmitting urogenital and intestinal schistosomiasis, respectively. Since the underlying distribution of snails is partially known, often being focal, developing pragmatic spatial models that interpolate snail information across under-sampled regions is required to understand and assess current and future risk of schistosomiasis.MethodsA secondary geospatial analysis of recently collected malacological and environmental survey data was undertaken. Using a Bayesian Poisson latent Gaussian process model, abundance data were fitted for Bulinus and Biomphalaria. Interpolating the abundance of snails along the shoreline (given their relative distance along the shoreline) was achieved by smoothing, using extracted environmental rainfall, land surface temperature (LST), evapotranspiration, normalised difference vegetation index (NDVI) and soil type covariate data for all predicted locations. Our adopted model used a combination of two-dimensional (2D) and one dimensional (1D) mapping.ResultsA significant association between normalised difference vegetation index (NDVI) and abundance of Bulinus spp. was detected (log risk ratio − 0.83, 95% CrI − 1.57, − 0.09). A qualitatively similar association was found between NDVI and Biomphalaria sp. but was not statistically significant (log risk ratio − 1.42, 95% CrI − 3.09, 0.10). Analyses of all other environmental data were considered non-significant.ConclusionsThe spatial range in which interpolation of snail distributions is possible appears < 10km owing to fine-scale biotic and abiotic heterogeneities. The forthcoming challenge is to refine geospatial sampling frameworks with future opportunities to map schistosomiasis within actual or predicted snail distributions. In so doing, this would better reveal local environmental transmission possibilities.Graphical

Evaluation of the prophylactic and therapeutic efficacies of mucus and tissue nucleoproteins extracted from Biomphalaria alexandrina snails on schistosomiasis mansoni.

Schistosomiasis is a neglected tropical disease with considerable morbidity. The lone effective drug, praziquantel (PZQ), is showing emergence of drug resistance hence, searching for new supportive treatment is crucial. This study aimed to evaluate the efficacy of mucus and nucleoproteins (NPs) extracted from Biomphalaria alexandrina (B. alexandrina) snails on miracidia, cercariae and Schistosoma mansoni (S. mansoni) adults in vitro and assess their experimental in vivo effect through parasitological, histopathological, and biochemical parameters. The in vivo study included 90 male Swiss albino mice. Mice were grouped into 9 groups; G1-G5 were infected and treated with; GI: PZQ, GII: mucus, GIII: combined PZQ and mucus, GIV: NPs, GV: combined PZQ and NPs. Control groups; C1: Non infected non treated (negative control), C2: Infected non treated (positive control), C3: Non infected mucus treated and C4: Non infected NPs treated. The in vitro study proved that the mucus had a better lethal effect on cercariae than miracidia, while NPs had better lethal effect on miracidia. The mucus lethal effect on adults surpassed the NPs as 100% and 60%, respectively. The in vivo study proved that the combined NPs or mucus with PZQ added to the effect of individual PZQ resulting in 100% total worm burden (TWB) reduction. As regard oxidative stress markers, the lowest level of nitric oxide (NO) was shown with combined PZQ and NPs. While, the highest glutathione (GSH) level was produced by individual PZQ. The study concluded that mucus and NPs of B. alexandrina had cercaricidal, miracidicidal and anti-schistosomal effect in vitro and that their combination could be considered a contribution to PZQ potentiality in vivo.

Educational interventions about intestinal parasitosis and schistosomiasis applied to school students in Rio de Janeiro

Este estudo objetivou analisar atividades de intervenções educativas como forma de mediar informações sobre parasitoses intestinais e esquistossomose com escolares no estado do Rio de Janeiro. As obras foram recuperadas em diferentes plataformas até 2021, sendo analisados formato e conteúdo de Parasitologia. Foram recuperadas 19 obras, cuja atividades foram aplicadas principalmente em escolas estaduais (47,3%), no ensino fundamental II (73,7%) e nas escolas da cidade do Rio de Janeiro. O jogo foi a estratégia mais utilizada (68,4%) e os parasitos mais abordados foram Ascaris lumbricoides e Giardia duodenalis. A partir das análises verificou-se que as atividades aplicadas foram consideradas estratégias de ensino interessantes, que merecem ser utilizadas nas escolas para tornar os conteúdos mais atraentes.

Molecular tracing of Biomphalaria straminea in China

To investigate the origin of Biomphalaria straminea in China, so as to provide insights into assessment of schistosomiasis mansoni transmission risk and B. straminea control. Guanlan River, Dasha River, Shenzhen Reservoir, upper and lower reaches of Kuiyong River, and Xinzhen River in Shenzhen, China, were selected as sampling sites. Ten Biomphalaria samples were collected from each site, and genomic DNA was extracted from Biomphalaria samples. DNA samples were obtained from 15 B. straminea sampled from 5 sampling sites in Minas Gerais State, Pará State, Federal District, Pernambuco State, and Sao Paulo State in Brazil, South America. Cytochrome c oxidase I (COI) and mitochondrial 16S ribosomal RNA (16S rRNA) genes were sampled using the above DNA templates, and the amplified products were sequenced. The COI and 16S rRNA gene sequences were downloaded from GenBank, and the sampling sites were acquired. All COI and 16S rRNA gene sequences were aligned and evolutionary trees of B. straminea were created based on COI and 16S rRNA gene sequences to identify the genetic similarity and evolutionary relationship between B. straminea samples from China and South America. A total of 60 COI gene sequences with a length of 529 bp and 3 haplotypes were obtained from B. straminea sampled from China. There were 165 COI gene sequences of B. straminea retrieved from GenBank, and following alignment with the above 60 gene sequences, a total of 33 haplotypes were obtained. Phylogenetic analysis showed that the three haplotypes of B. straminea from China were clustered into one clade, among which the haplotype China11 and three B. straminea samples from Brazil retrieved from GenBank belonged to the same haplotype. Geographical evolution analysis showed that the B. straminea samples from three sampling sites along eastern coasts of Brazil had the same haplotype with China11, and B. straminea samples from other two sampling sites were closely, genetically related to China11. A total of 60 16S rDNA gene sequences with approximately 322 bp in length were amplified from B. straminea in China, with 2 haplotypes identified. A total of 70 16S rDNA gene sequences of B. straminea were captured from GenBank. Phylogenetic analysis showed that Biomphalaria snails collected from China were clustered into a clade, and the haplotype China64 and the haplotype 229BS from Brazil shared the same haplotype. The 49 16S rDNA gene sequences of B. straminea from 25 sampling sites in southern Brazil, which were captured from GenBank, were included in the present analysis, and the B. straminea from 3 sampling sites shared the same haplotype with China64 in China. Geographical evolution analysis based on COI and 16S rRNA gene sequences showed that B. straminea sampled from eastern coastal areas of Brazil shared the same haplotypes in two gene fragment sequences with Biomphalaria snails collected from China. The Biomphalaria snails in China are characterized as B. straminea, which have a low genetic diversity. The Biomphalaria snails in China have a high genetic similarity with B. straminea sampled from eastern coastal areas of Brazil, which may have originated from the eastern coastal areas of Brazil.

Different metazoan parasites, different transcriptomic responses, with new insights on parasitic castration by digenetic trematodes in the schistosome vector snail Biomphalaria glabrata

BackgroundGastropods of the genus Biomphalaria (Family Planorbidae) are exploited as vectors by Schistosoma mansoni, the most common causative agent of human intestinal schistosomiasis. Using improved genomic resources, overviews of how Biomphalaria responds to S. mansoni and other metazoan parasites can provide unique insights into the reproductive, immune, and other systems of invertebrate hosts, and their responses to parasite challenges.ResultsUsing Illumina-based RNA-Seq, we compared the responses of iM line B. glabrata at 2, 8, and 40 days post-infection (dpi) to single infections with S. mansoni, Echinostoma paraensei (both digenetic trematodes) or Daubaylia potomaca (a nematode parasite of planorbid snails). Responses were compared to unexposed time-matched control snails. We observed: (1) each parasite provoked a distinctive response with a predominance of down-regulated snail genes at all time points following exposure to either trematode, and of up-regulated genes at 8 and especially 40dpi following nematode exposure; (2) At 2 and 8dpi with either trematode, several snail genes associated with gametogenesis (particularly spermatogenesis) were down-regulated. Regarding the phenomenon of trematode-mediated parasitic castration in molluscs, we define for the first time a complement of host genes that are targeted, as early as 2dpi when trematode larvae are still small; (3) Differential gene expression of snails with trematode infection at 40dpi, when snails were shedding cercariae, was unexpectedly modest and revealed down-regulation of genes involved in the production of egg mass proteins and peptide processing; and (4) surprisingly, D. potomaca provoked up-regulation at 40dpi of many of the reproduction-related snail genes noted to be down-regulated at 2 and 8dpi following trematode infection. Happening at a time when B. glabrata began to succumb to D. potomaca, we hypothesize this response represents an unexpected form of fecundity compensation. We also document expression patterns for other Biomphalaria gene families, including fibrinogen domain-containing proteins (FReDs), C-type lectins, G-protein coupled receptors, biomphalysins, and protease and protease inhibitors.ConclusionsOur study is relevant in identifying several genes involved in reproduction that are targeted by parasites in the vector snail B. glabrata and that might be amenable to manipulation to minimize their ability to serve as vectors of schistosomes.

Aligning antimicrobial resistance surveillance with schistosomiasis research: an interlinked One Health approach.

One Health surveillance involves the analysis of human, animal and environmental samples, recognising their interconnectedness in health systems. Such considerations are crucial to investigate the transmission of many pathogens, including drug-resistant bacteria and parasites. The highest rates of antimicrobial resistance (AMR)-associated deaths are observed in sub-Saharan Africa, where concurrently the waterborne parasitic disease schistosomiasis can be highly endemic in both humans and animals. Although there is growing acknowledgment of significant interactions between bacteria and parasites, knowledge of relationships between schistosomes, microbes and AMR remains inadequate. In addition, newly emergent research has revealed the previously underappreciated roles of animals and the environment in both AMR and schistosomiasis transmission. We consider shared environmental drivers and colonisation linkage in this narrative review, with a focus on extended-spectrum beta-lactamase-mediated resistance among bacteria from the Enterobacteriaceae family, which is exceedingly prevalent and responsible for a high burden of AMR-associated deaths. Then we examine novel findings from Malawi, where the landscapes of AMR and schistosomiasis are rapidly evolving, and make comparisons to other geographic areas with similar co-infection epidemiology. We identify several knowledge gaps that could be addressed in future research, including the need to characterise the impact of intestinal schistosomiasis and freshwater contact on intestinal AMR colonisation, before proposing a rationale for connecting AMR surveillance and schistosomiasis research within a One Health framework.

Comparison of the Loop-Mediated Isothermal Amplification (LAMP) and the Kato-Katz Techniques in the Diagnosis of &amp;lt;i&amp;gt;Schistosoma mansoni&amp;lt;/i&amp;gt; in Burkina Faso

Intestinal schistosomiasis or intestinal bilharzia, mainly caused by &amp;lt;i&amp;gt;Schistosoma mansoni&amp;lt;/i&amp;gt;, is one of the most common parasitic diseases in the world, and a neglected tropical disease (NTD). It ranks first among water-borne diseases and is the 2nd most endemic parasitic disease after malaria and according to the World Health Organization (WHO), schistosomiasis is transmitted in more than 78 countries and territories in tropical and subtropical regions, and more than 250 million people are infected, mainly in Africa. Kato Katz (KK) remains the standard technique for diagnosing this disease. A promising new approach, loop-mediated isothermal amplification (LAMP), may be needed in developing countries such as Burkina Faso. Thus, the aim of this study was to compare the LAMP technique and the Kato-Katz technique in the diagnosis of &amp;lt;i&amp;gt;Schistosoma mansoni&amp;lt;/i&amp;gt; in Burkina Faso. 52 stool samples were collected from patients in the town of Bobo Dioulasso and examined using the KK technique, which corresponds to microscopy and the LAMP technique, to assess the sensitivity and specificity of this molecular technique. The results showed a prevalence of intestinal schistosomiasis of 8% in the study, and the Kappa coefficient obtained between the 2 techniques was 0.99, roughly equal to 1. The sensitivity and specificity of the LAMP molecular test was 100%.

Soil-Transmitted Helminthiasis, Intestinal Schistosomiasis and Malaria Co-Infections among Children in Rural Communities Around Rwasave and Cyarwa Valleys

Background: Soil-transmitted helminthiasis, schistosomiasis and malaria remain a threat in developing countries, especially to people living in rural areas near large water bodies, valleys or swamps whose daily life activities revolve around those areas. In addition, these parasites affect different groups of people especially those in contact with their breeding sites including children mostly due to their developing immunity compared to that of old people. Methodology: This cross-sectional study was conducted in rural communities near the Rwasave and Cyarwa valleys, with 124 school-aged children participating. Stool samples were tested for the presence of STH eggs and intestinal Schistosoma parasites using the Kato Katz technique, and thick blood smears were made to aid in the identification of plasmodium species in blood. The threshold intensity of infection on STHs and Schistosoma sp. was estimated by counting their eggs microscopically, which aided in classifying infections as light, moderate, or heavy according to WHO standards. Furthermore, Plasmodium species were identified by the presence of schizonts, trophozoites, or gametocytes on Giemsa-stained thick blood smears, and parasitic density was calculated as a result. Results: In this study, the highest prevalence of soil transmitted helminthiasis was 12.7% in Cyarwa valley compared to 12.5% in Rwasave valley. The highest prevalence of Schistosomiasis was 3.2% in Cyarwa valley compared to 1.3% in Rwasave valley. Prevalence of malaria in Cyarwa valley was 3.3% in 63 children. Where children infected were only males falling in 5-8 age group. Conclusion: Results showed high prevalence of soil transmitted helminthiasis which was 12.7% in Cyarwa compared to 12.5% in Rwasave valley especially in children aged 5-8, this due to poor sanitation (P&lt;0.001) that have assessed. Surprisingly, Cyarwa valley is located nearby town. Whereas malaria, intestinal schistosomiasis was low and there were not significantly associated with their risk factors with p-values 0.4, 0.092 respectively which can show that, preventive measures that have been established by government of Rwanda have positive impacts. Furthermore, there was a low prevalence of soil transmitted helminthiasis, intestinal schistosomiasis and malaria co-infection. Keywords: soil transmitted helminthiasis, intestinal schistosomiasis, malaria.

Barriers and misconceptions hindering reduction of intestinal schistosomiasis in Mbita Sub-County, Western Kenya

BackgroundCommunity and individual participation are crucial for the success of schistosomiasis control. The World Health Organization (WHO) has highlighted the importance of enhanced sanitation, health education, and Mass Drug Administration (MDA) in the fight against schistosomiasis. These approaches rely on the knowledge and practices of the community to be successful; however, where the community knowledge is low and inappropriate, it hinders intervention efforts. Hence, it is essential to identify barriers and misconceptions related to awareness of schistosomiasis, sources of infection, mode of transmission, symptoms, and control measures.MethodsThis was a mixed-method cross-sectional study involving 1200 pre-school children randomly selected and examined for Schistosoma mansoni infection using the Kato-Katz technique. All parents/guardians of selected children were enrolled for a pre-tested questionnaire survey, while 42 were engaged in focus group discussions (FGDs). The level of knowledge and awareness among parents/guardians about schistosomiasis was evaluated in relation to the infection status of their pre-school children.ResultsAmong pre-school children, the prevalence of intestinal schistosomiasis was 45.1% (95% CI 41.7–48.5). A majority of parents/guardians (85.5%) had heard about schistosomiasis, and this awareness was associated with the participant’s level of education (OR = 0.16, 95% CI 0.08, 0.34). In addition, a positive association was observed between higher educational attainment and knowledge of the causative agent (OR = 0.69, 95% CI 0.49, 0.96). Low education level was significantly associated with limited knowledge of transmission through lake water contact (OR = 0.71, 95% CI 0.52, 0.97) and infection from the lake (OR = 0.33, 95% CI 0.19, 0.57). Notably, parents/guardians who have heard of schistosomiasis could not recognize symptoms of S. mansoni infection, such as abdominal pain (91.8%, 815/888) and blood in the stool (85.1%, 756/888). Surprisingly, 49.8% (442/888) incorrectly identified hematuria (blood in urine), a key sign of S. haematobium, but not S. mansoni, in an endemic area for S. mansoni infection. The majority (82.6%, 734/888) of parents/guardians were unaware that dams are potential infection sites, despite 53.9% (479/888) of their pre-school-aged children testing positive for schistosome infection.ConclusionsDespite the high level of awareness of intestinal schistosomiasis in the study area, we identified a low level of knowledge regarding its causes, modes of transmission, signs and symptoms and potential sites of transmission within the community. This study emphasizes the need for targeted educational interventions to address the misconceptions and knowledge gaps surrounding intestinal schistosomiasis through tailored community-based programs.

Evaluation of Silybin Nanoparticles against Liver Damage in Murine Schistosomiasis mansoni Infection.

Silybin (SIB) is a hepatoprotective drug known for its poor oral bioavailability, attributed to its classification as a class IV drug with significant metabolism during the first-pass effect. This study explored the potential of solid lipid nanoparticles with (SLN-SIB-U) or without (SLN-SIB) ursodeoxycholic acid and polymeric nanoparticles (PN-SIB) as delivery systems for SIB. The efficacy of these nanosystems was assessed through in vitro studies using the GRX and Caco-2 cell lines for permeability and proliferation assays, respectively, as well as in vivo experiments employing a murine model of Schistosomiasis mansoni infection in BALB/c mice. The mean diameter and encapsulation efficiency of the nanosystems were as follows: SLN-SIB (252.8 ± 4.4 nm, 90.28 ± 2.2%), SLN-SIB-U (252.9 ± 14.4 nm, 77.05 ± 2.8%), and PN-SIB (241.8 ± 4.1 nm, 98.0 ± 0.2%). In the proliferation assay with the GRX cell line, SLN-SIB and SLN-SIB-U exhibited inhibitory effects of 43.09 ± 5.74% and 38.78 ± 3.78%, respectively, compared to PN-SIB, which showed no inhibitory effect. Moreover, SLN-SIB-U demonstrated a greater apparent permeability coefficient (25.82 ± 2.2) than PN-SIB (20.76 ± 0.1), which was twice as high as that of SLN-SIB (11.32 ± 4.6) and pure SIB (11.28 ± 0.2). These findings suggest that solid lipid nanosystems hold promise for further in vivo investigations. In the murine model of acute-phase Schistosomiasis mansoni infection, both SLN-SIB and SLN-SIB-U displayed hepatoprotective effects, as evidenced by lower alanine amino transferase values (22.89 ± 1.6 and 23.93 ± 2.4 U/L, respectively) than those in control groups I (29.55 ± 0.7 U/L) and I+SIB (34.29 ± 0.3 U/L). Among the prepared nanosystems, SLN-SIB-U emerges as a promising candidate for enhancing the pharmacokinetic properties of SIB.