Home-Made Lateral Flow Test Strip Versus POC-CCA Assay for Detection of Active Schistosomiasis in Egypt.

BACKGROUND: For years, the Kato-Katz (KK) technique has been considered the gold standard for diagnosing schistosomiasis. The aim of this study was to compare the effectiveness of our previously developed gold nanoparticle-based lateral flow test strip (AuNPs-LFTS) for diagnosing active Schistosoma mansoni with that of the commercially available point-of-care Circulating Cathodic Antigen detection (POC-CCA) kit. METHODS: In this study, we collected sixty positive and twenty negative urine samples from patients in endemic hot spots in the Nile Delta, as well as from patients visiting the internal medicine clinic at Theodor Bilharz Research Institute (TBRI). We produced monoclonal antibodies (MAbs) against S. mansoni soluble egg antigen (SEA) from cloned hybridoma cells (4D/1D). These MAbs were conjugated with gold and mesoporous silica nanoparticles, and used to develop the LFTS. RESULTS: The LFTS demonstrated a limit of detection (LoD) of 3 ng/ml. The sensitivity and specificity of the developed LFTS were found to be 96.7% and 95%, respectively, compared to 85% and 90% for the POC-CCA detection kit. The cases were divided into groups based on egg count in the stool, categorized as light, moderate, and heavy infections. The sensitivity of the LFTS in the group with light infection was higher than that of the POC-CCA. When using the KK technique (eggs per gram of stool sample [EPG]) as the reference test, the kappa value for the nano-based strips was 0.902, compared to 0.672 for the CCA strips, indicating an almost perfect agreement between KK and our developed LFTS. CONCLUSION: These results confirm the reliability and effectiveness of the LFTS compared to commercially available kits for rapid, sensitive, and early diagnosis of schistosomiasis. However, it is recommended to conduct further assessments of the developed strip on a larger scale with a broader range of cases before considering its introduction to local or international markets.

Schistosoma japonicum infection-mediated downregulation of lncRNA Malat1 contributes to schistosomiasis hepatic fibrosis by the Malat1/miR-96/Smad7 pathway.

BACKGROUND: Schistosoma japonicum infection causes hepatic fibrosis, a primary cause of morbidity and mortality associated with the disease, and effective treatments are still lacking. Long non-coding RNAs (lncRNAs) have been implicated in the pathogenic process of various tissue fibroses. However, the role of lncRNAs in schistosomiasis hepatic fibrosis (HF) is poorly understood. Understanding the role of lncRNAs in schistosomiasis HF will enhance knowledge of disease processes and aid in the discovery of therapeutic targets and diagnostic biomarkers. METHODS: Differentially expressed lncRNA profiles in primary hepatic stellate cells (HSCs) of mice infected with S. japonicum were identified using high-throughput lncRNA sequencing. Primary HSCs were isolated from infected mice using collagenase digestion and density-gradient centrifugation, cultured in DMEM with 10% fetal bovine serum. Dual-luciferase reporter assays, nuclear cytoplasm fractionation and RIP assays were employed to assess the relationship between Malat1 and miRNA-96. Malat1 lentivirus and ASO-Malat1 were constructed for forced expression and downregulated expression of Malat1. The Malat1-KO mouse was constructed by CRISPR/Cas9 technology. Pathological features of the liver were evaluated by hematoxylin-eosin (HE), Masson's trichrome staining and immunohistochemistry (IHC). The expression levels of fibrosis-related genes were determined by quantitative real-time PCR (qRT-PCR) and Western blot. RESULTS: A total of 1561 differentially expressed lncRNAs were identified between infected and uninfected primary HSCs. Among the top altered lncRNAs, the downregulated Malat1 was observed in infected HSCs and verified by qPCR. Treatment of infected mice with praziquantel (PZQ) significantly increased the Malat1 expression. Elevated Malat1 expression in infected primary HSC reduced the expressions of profibrogenic genes, whereas Malat1 knockdown had the opposite effect. Moreover, Malat1 was found to interact with miR-96, a profibrotic miRNA, by targeting Smad7. Forced Malat1 expression reduced miR-96 levels in infected primary HSCs, attenuating fibrogenesis and showing negative correlation between Malat1 expression and the expression levels of miR-96 and profibrogenic genes α-SMA and Col1α1. Notably, in Malat1-KO mice, knockout of Malat1 aggravates schistosomiasis HF, while restored Malat1 expression in the infected HSCs reduced the expression of profibrogenic genes. CONCLUSIONS: We demonstrate that lncRNA is involved in regulation of schistosomiasis HF. Elevated lncRNA Malat1 expression in infected HSCs reduces fibrosis via the Malat1/miR-96/Smad7 pathway, thus providing a novel therapeutic target for schistosomiasis HF. Furthermore, Malat1 expression is sensitive to PZQ treatment, thus offering a potential biomarker for assessing the response to chemotherapy.

Elimination of schistosomiasis mekongi in reach for Lao PDR: The last patient with severe disease?

Schistosomiasis mekongi is endemic in a restricted area in Northern Cambodia and the Southern Lao People's Democratic Republic. Severe hepatobiliary morbidity is associated with chronic untreated S. mekongi infection. Since the 1980s extensive control efforts have been employed in endemic areas, resulting in substantial reduction of infection rates and disease burden. We report on a patient with a fatal course of clinically-assessed chronic schistosomiasis. This report underscores that patients with severe chronic Mekong schistosomiasis may still exist and may need treatment support.

Safety and Efficacy of Praziquantel in Pregnant Women Infected with Schistosoma haematobium in Lambaréné, Gabon - Clinical Results from the Randomized, Single-Blinded, Controlled freeBILy-Gabon Trial.

OBJECTIVE: Despite evidence of praziquantel's safety for treating schistosomiasis in pregnancy, many countries withhold treatment. Only two randomized controlled trials have investigated praziquantel in pregnancy, none involving Schistosoma haematobium. METHODS: Pregnant women during second trimester in Lambaréné (Gabon) were screened for S. haematobium infection using urine microscopy and circulating anodic antigen detection. Participants positive for either test were randomized (3:1) to single-dose praziquantel 40mg/kg during pregnancy versus no treatment during pregnancy. Investigators were blinded for allocation. Primary outcomes were reduction of egg- (ERR) and antigen production (IRR) while explorative outcomes included assessment of cure rate, adverse events, maternal hemoglobin levels maternal anemia prevalence at delivery, pregnancy outcomes, and newborn anthropometric parameters. RESULTS: Of 761 women screened 165 were eligible and randomized (intervention n=124, control n=41). 124 completed the study (n=90 and n=34, respectively). Tretament led to a significant higher ERR (95.0%[91%-97%] vs. 27.0%[-42%-63%]) and IRR (95%[91%-97%] vs. 56%[14%-78%]). Common adverse events were dizziness, nausea, and vomiting. Maternal anemia at delivery was significantly lower in the intervention group (OR:0.40[0.16;0.96],p=0.04). No increased risk for adverse pregnancy outcomes was observed. CONCLUSIONS: This first randomized controlled trial investigating praziquantel in pregnant women with S. haematobium found praziquantel to be safe, effective and reducing maternal anemia. We recommend treating confirmed infections to prevent morbidity in pregnant women.

Awareness of Primary Care Providers on Genital Schistosomiasis Infection in Northern Nigeria.

BACKGROUND: Genital schistosomiasis (GS) is a debilitating neglected tropical disease caused by Schistosoma haematobium. Despite its significant impact on reproductive health, awareness and knowledge of GS among healthcare providers, especially in Sub-Saharan Africa, remain inadequate, leading to underdiagnosis and mistreatment. METHODS: This study conducted a cross-sectional online survey to assess the awareness and knowledge of GS among 139 primary healthcare providers in Northern Nigeria. A semi-structured self-administered questionnaire was utilized, covering various aspects of GS including its aetiopathogenesis, clinical features, complications, diagnosis, and prevention/treatment. Respondents were scored based on their answers, with an overall score of ≥35 considered indicative of good awareness. RESULTS: Most respondents were aged 31-50 years (41.0%), male (59.7%), married (84.9%), and working in the public sector (97.8%). Mean scores indicated varying levels of awareness across different aspects of GS, with higher awareness regarding aetiopathogenesis (13.99 ±3.275) and prevention/treatment (11.27±1.592). However, awareness of complications remained comparatively lower. Overall, 43.9% of respondents demonstrated good awareness of GS. Regional disparities in awareness were observed, with the North-western region exhibiting the highest awareness (52.6%) followed by the Northeast (40.6%) and Northcentral regions (36.0%). CONCLUSION: The study underscores the urgent need for targeted educational interventions to enhance healthcare providers' knowledge of GS, particularly in regions with lower awareness levels. Improving awareness and knowledge among primary healthcare providers can facilitate early detection, appropriate management, and prevention strategies, thus alleviating the burden of GS on affected communities in Northern Nigeria and beyond.

CONTEXTE: La schistosomiase génitale (SG) est une maladie tropicale négligée et débilitante causée par Schistosoma haematobium. Malgré son impact significatif sur la santé reproductive, la connaissance et la sensibilisation à la SG parmi les prestataires de soins de santé, en particulier en Afrique subsaharienne, restent insuffisantes, conduisant à un sous-diagnostic et à des traitements inappropriés. MÉTHODES: Cette étude a mené une enquête transversale en ligne pour évaluer la connaissance et la sensibilisation à la SG parmi 139 prestataires de soins de santé primaires dans le nord du Nigéria. Un questionnaire semi-structuré auto-administré a été utilisé, couvrant divers aspects de la SG, notamment son étiopathogénie, ses caractéristiques cliniques, ses complications, son diagnostic, ainsi que sa prévention et son traitement. Les répondants ont été notés en fonction de leurs réponses, un score global de ≥ 35 étant considéré comme indicatif d'une bonne connaissance. RÉSULTATS: La plupart des répondants avaient entre 31 et 50 ans (41,0%), étaient des hommes (59,7 %), mariés (84,9 %) et travaillaient dans le secteur public (97,8 %). Les scores moyens indiquaient des niveaux variables de sensibilisation aux différents aspects de la SG, avec une meilleure connaissance de l'étiopathogénie (13,99 ± 3,275) et de la prévention/traitement (11,27 ± 1,592). Cependant, la sensibilisation aux complications restait comparativement plus faible. Globalement, 43,9 % des répondants ont montré une bonne connaissance de la SG. Des disparités régionales dans la sensibilisation ont été observées, la région du nord-ouest affichant la plus grande sensibilisation (52,6 %), suivie des régions du nord-est (40,6 %) et du centre-nord (36,0 %). CONCLUSION: L'étude souligne la nécessité urgente d'interventions éducatives ciblées pour améliorer les connaissances des prestataires de soins de santé sur la SG, en particulier dans les régions où les niveaux de sensibilisation sont plus faibles. Améliorer la sensibilisation et les connaissances des prestataires de soins de santé primaires peut faciliter la détection précoce, la gestion appropriée et les stratégies de prévention, atténuant ainsi le fardeau de la SG sur les communautés touchées dans le nord du Nigéria et au-delà. MOTS-CLÉS: Sensibilisation, Prestataires de soins primaires, Schistosomiase génitale, Nord du Nigéria.

Structure-Based Discovery of Phytocompounds from Azadirachta indica as Potential Inhibitors of Thioredoxin Glutathione Reductase in Schistosoma mansoni.

Schistosomiasis, a parasitic disease caused by Schistosoma species such as S. haematobium, S. mansoni, and S. japonicum, poses a significant global health burden. The thioredoxin glutathione reductase (TGR) enzyme, crucial for maintaining the parasite's redox balance and preventing oxidative stress, has been identified as a promising target for anti-schistosomal drug development. This study aims to identify potential TGR inhibitors from Azadirachta indica phytochemicals using molecular modeling approaches. We screened 60 compounds derived from A. indica bark and leaves through molecular docking to assess their binding affinity, followed by the evaluation of binding-free energies for the most promising candidates. Drug-likeness and pharmacokinetic properties were assessed, and molecular dynamics simulations were conducted to explore the conformational stability of the protein-ligand complexes. Our findings revealed that several A. indica compounds exhibited significantly lower docking scores (up to -9.669 kcal/mol) compared to the standard drug praziquantel (-4.349 kcal/mol). Notably, Isorhamnetin, Isomargolonone, Nimbaflavone, Quercetin, and Nimbionol demonstrated strong interactions with TGR, although Isorhamnetin showed potential mutagenicity. Further binding free energy calculations and molecular dynamics simulations confirmed the stability of Isomargolonone, Nimbionol, and Quercetin as potential TGR inhibitors. In conclusion, these findings suggest that Isomargolonone, Nimbionol, and Quercetin warrant further experimental validation as promising candidates for anti-schistosomal therapy.

Mapping of schistosome hybrids of the haematobium group in West and Central Africa.

Hybridization of parasitic species is an emerging health problem in the evolutionary profile of infectious disease, particularly within trematodes of the genus Schistosoma. Because the consequences of this hybridization are still relatively unknown, further studies are needed to clarify the epidemiology of the disease and the biology of hybrid schistosomes. In this article, we provide a detailed review of published results on schistosome hybrids of the haematobium group. Using a mapping approach, this review describes studies that have investigated hybridization in human (S. haematobium, S. guineensis, and S. intercalatum) and animal (S. bovis and S. curassoni) schistosome species in West Africa (Niger, Mali, Senegal, Côte d'Ivoire, Benin, Nigeria) and in Central Africa (Cameroon, Gabon, Democratic Republic of Congo), as well as their limitations linked to the underestimation of their distribution in Africa. This review provides information on studies that have highlighted hybrid species of the haematobium group and the regions where they have been found, notably in West and Central Africa.

Methodological assessment for efficient collection of Schistosoma mansoni environmental DNA and improved schistosomiasis surveillance in tropical wetlands.

Schistosomiasis, caused by trematodes of genus Schistosoma, is among the most seriously neglected tropical diseases. Although rapid surveillance of risk areas for Schistosoma transmission is vital to control schistosomiasis, the habitat and infection status of this parasite are difficult to assess. Environmental DNA (eDNA) analysis, involving the detection of extra-organismal DNA in water samples, facilitates cost-efficient and sensitive biomonitoring of aquatic environments and is a promising tool to identify Schistosoma habitat and infection risk areas. However, in tropical wetlands, highly turbid water causes filter clogging, thereby decreasing the filtration volume and increasing the risk of false negatives. Therefore, in this study, we aimed to conduct laboratory experiments and field surveys in Lake Victoria, Mbita, to determine the appropriate filter pore size for S. mansoni eDNA collection in terms of particle size and filtration volume. In the laboratory experiment, aquarium water was sequentially filtered using different pore size filters. Targeting >3 µm size fraction was found to be sufficient to capture S. mansoni eDNA particles, regardless of their life cycle stage (egg, miracidia, and cercaria). In the field surveys, GF/D (2.7 µm nominal pore size) filter yielded 2.5-times the filtration volume obtained with a smaller pore size filter and pre-filtration methods under the same time constraints. Moreover, a site-occupancy model was applied to the field detection results to estimate S. mansoni eDNA occurrence and detection probabilities and assess the number of water samples and PCR replicates necessary for efficient eDNA detection. Overall, this study reveals an effective method for S. mansoni eDNA detection in turbid water, facilitating the rapid and sensitive monitoring of its distribution and cost-effective identification of schistosomiasis transmission risk areas.

The abundance of snail hosts mediates the effects of antagonist interactions between trematodes on the transmission of human schistosomes.

BACKGROUND: Combating infectious diseases and halting biodiversity loss are intertwined challenges crucial to ensure global health. Biodiversity can constrain the spread of vector-borne pathogens circulation, necessitating a deeper understanding of ecological mechanisms underlying this pattern. Our study evaluates the relative importance of biodiversity and the abundance of Bulinus truncatus, a major intermediate host for the trematode Schistosoma haematobium on the circulation of this human pathogen at aquatic transmission sites. METHODS: We combined mathematical modelling and a molecular based empirical study to specifically assess the effect of co-infections between S. haematobium and other trematodes within their B. truncatus snail hosts; and B. truncatus abundance at transmission sites, on the production of S. haematobium infective cercariae stages released into the aquatic environment. RESULTS: Our modelling approach shows that more competitive trematode species exploiting B. truncatus as an intermediate host at the transmission site level leads to higher co-infection rates within snail hosts, subsequently reducing the production of S. haematobium cercariae. Conversely, an increase in B. truncatus abundance results in lower co-infection rates, and a higher proportion of S. haematobium cercariae released into the environment. Our empirical data from the field support these findings, indicating a significant negative effect of local trematode species richness (P-value = 0.029; AIC = 14.9) and co-infection rates (P-value = 0.02, AIC = 17.4) on the dominance of S. haematobium based on our GLMM models, while B. truncatus abundance positively influences S. haematobium dominance (P-value = 0.047, AIC = 20.1). CONCLUSIONS: Our study highlights the importance of biodiversity in influencing the transmission of S. haematobium through the effect of antagonistic interactions between trematodes within bulinid snail hosts. This effect intensifies when B. truncatus populations are low, promoting co-infections within snails. In line with the One Health concept, our results suggest that maintaining high level of freshwater biodiversity to sustain global trematode diversity at transmission sites can help reducing the circulation of Schistosoma species locally.

Precision mapping of snail habitat in lake and marshland areas: Integrating environmental and textural indicators using Random Forest modeling.

Schistosomiasis japonica continues to pose a significant public health challenge in China, primarily due to the widespread distribution of Oncomelania hupensis, the sole intermediate host of Schistosoma. This study aims to address the constraints of existing remote sensing analyses for identifying snail habitats, which frequently neglect spatial scale and seasonal variations. To this end, we adopt a multi-source data-driven Random Forest approach that integrates bottomland and ground-surface texture data with traditional environmental variables, enhancing the accuracy of snail habitat assessments. We developed four distinct models for the lake and marshland areas of Guichi, China: a baseline model incorporating ground-surface texture, bottomland variables, and environmental variables; Model 1 with only environmental variables; Model 2 adding ground-surface texture and environmental variables; and Model 3 integrating bottomland with environmental variables. The baseline model outperformed the others, achieving a true skill statistic of 0.93, an accuracy of 0.97, a kappa statistic of 0.94, and an area under the curve of 0.99. Our analysis pinpointed critical high-risk snail habitats distributed in a belt-like pattern along major water bodies, near the Yangtze River, QiuPu River, and around Shengjin Lake, Jiuhua River, and Qingtong River. These insights can aid local health authorities in more efficiently allocating limited resources, developing effective snail surveillance and control strategies to combat schistosomiasis. Additionally, this approach can be adapted to localize other endemic hosts with similar ecological characteristics.

Hepatic schistosomiasis as a determining factor in the development of hepatic granulomas and liver fibrosis: a review of the current literature.

Hepatic schistosomiasis is a neglected parasitosis that affects millions of people each year worldwide and leads to high healthcare costs and increased morbidity and mortality in infected humans. It is a disease that has been widely studied in terms of its pathophysiology; therefore, the signaling pathways that lead to liver damage, with the consequent development of liver fibrosis, are now better understood. Research has elucidated the role of soluble egg antigen in the development of hepatic granulomas and liver fibrosis, the signal transducer and activator of transcription 3 and its participation in liver damage, the role of heat shock protein 47 and its involvement in liver fibrosis, the anti-inflammatory effects caused by interleukin-37, and the role of natural killer and natural killer T cells in the development of the disease. Hepatic schistosomiasis can range from simple hepatomegaly to the development of portal hypertension combined with hepatic fibrosis. For diagnostic purposes, a microscopic examination of excreta remains the gold standard; however, abdominal ultrasound has recently taken on an important role in the assessment of liver lesions produced by the parasite. Praziquantel is considered the management drug of choice, and has been associated with a potential preventive antifibrotic effect.

Freshwater snail-borne parasitic diseases in Africa.

BACKGROUND: Freshwater snails are the first obligatory intermediate hosts in the trematode life cycle. Several parasitic diseases transmitted by these snails are endemic in Africa, and their distribution closely follows that of the intermediate hosts. These diseases represent a major public health problem and cause significant socio-economic losses in Africa, particularly schistosomiasis and fascioliasis. In this review, we will describe the main roles of freshwater snails in the life cycle of trematode parasites, and the geographical distribution of these diseases in Africa. We will also discuss the different techniques for detecting parasitic infections in snails, as well as the various methods of controlling snails and the larval stages of parasites. METHODS: We carried out a literature search for articles dealing with parasitic diseases transmitted by freshwater snail hosts in Africa. The search was conducted in databases such as PubMed, Web of Science and Google Scholar using various search terms combined by Boolean operators. Our search was limited to peer-reviewed articles less than 10 years old. Articles published to date in the fields of control of parasitic diseases transmitted by freshwater snails were included. Results were presented in narrative and in table format. RESULTS: The results of the database search identified 1007 records. We included 84 studies in this review. These studies generally focused on freshwater snails and the diseases they transmit. We described the geographical distribution of 43 freshwater species belonging to nine snail families, as well as the parasites that infect them. Several methods for diagnosing parasites in their snail hosts have been described, including microscopic and molecular methods, as well as antibody and protein barcode-based techniques. Molluscicides have been described as the main strategy for snail control. CONCLUSION: This study highlights several elements of knowledge about diseases transmitted by freshwater snails and their distribution. A good understanding of snail infection detection techniques and existing control methods is an essential component in adapting control strategies for these diseases.

Exploring the genome-wide transcriptomic responses of Bulinus truncatus to Schistosoma haematobium infection: An important host-parasite system involved in the transmission of human urogenital schistosomiasis.

Freshwater snails of the genus Bulinus are critical hosts for Schistosoma haematobium, the causative agent of urogenital schistosomiasis. Among the 37 recognized Bulinus species, B. truncatus is a key vector. Using RNA sequencing (RNAseq), we investigated the genome-wide transcriptional responses of B. truncatus to S. haematobium infection. Our findings suggest that snails employ a complex defense strategy against the parasites by up-regulating genes involved in immune response, stress reaction, structural integrity, metabolism, and detoxification. In response, schistosome parasites appear to manipulate the snail's defense system, as evidenced by the suppression of immune-related genes such as ficolin, peptidoglycan recognition protein, and C-type lectin domain-containing protein genes. The down-regulation of biomphalysin 9, compared to its function in Biomphalaria glabrata, indicates divergent immune strategies among snail hosts. Additionally, we compared transcriptome profiles between embryos and juveniles, providing insights into developmental processes. This study offers valuable genomic data for Bulinus snails, illuminating the molecular interactions between bulinids and schistosomes, and advancing our understanding of their developmental biology.

Socio-economic risk factors for intestinal helminthiases in selected endemic communities in Mindanao, the Philippines: a cross-sectional study.

BACKGROUND: Parasitic neglected tropical diseases (NTDs) or 'infectious diseases of poverty' continue to affect the poorest communities in the world, including in the Philippines. Socio-economic conditions contribute to persisting endemicity of these infectious diseases. As such, examining these underlying factors may help identify gaps in implementation of control programs. This study aimed to determine the prevalence of schistosomiasis and soil-transmitted helminthiasis (STH) and investigate the role of socio-economic and risk factors in the persistence of these diseases in endemic communities in the Philippines. METHODS: This cross-sectional study involving a total of 1,152 individuals from 386 randomly-selected households was conducted in eight municipalities in Mindanao, the Philippines. Participants were asked to submit fecal samples which were processed using the Kato-Katz technique to check for intestinal helminthiases. Moreover, each household head participated in a questionnaire survey investigating household conditions and knowledge, attitude, and practices related to intestinal helminthiases. Associations between questionnaire responses and intestinal helminth infection were assessed. RESULTS: Results demonstrated an overall schistosomiasis prevalence of 5.7% and soil-transmitted helminthiasis prevalence of 18.8% in the study population. Further, the household questionnaire revealed high awareness of intestinal helminthiases, but lower understanding of routes of transmission. Potentially risky behaviors such as walking outside barefoot and bathing in rivers were common. There was a strong association between municipality and prevalence of helminth infection. Educational attainment and higher "practice" scores (relating to practices which are effective in controlling intestinal helminths) were inversely associated with soil-transmitted helminth infection. CONCLUSION: Results of the study showed remaining high endemicity of intestinal helminthiases in the area despite ongoing control programs. Poor socio-economic conditions and low awareness about how intestinal helminthiases are transmitted may be among the factors hindering success of intestinal helminth control programs in the provinces of Agusan del Sur and Surigao del Norte. Addressing these sustainability gaps could contribute to the success of alleviating the burden of intestinal helminthiases in endemic areas.

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.

Intrapulmonary T Cells Are Sufficient for Schistosoma-Induced Pulmonary Hypertension.

BACKGROUND: Schistosomiasis is a parasitic infection that can cause pulmonary hypertension (PH). Th2 CD4 T cells are necessary for experimental Schistosoma-PH. However, if T cells migrate to the lung to initiate, the localized inflammation that drives vascular remodeling and PH is unknown. METHODS: Mice were sensitized to Schistosoma mansoni eggs intraperitoneally and then challenged using tail vein injection. FTY720 was administered, which blocks lymphocyte egress from lymph nodes. T cells were quantified using flow cytometry, PH severity via heart catheterization, and cytokine concentration through ELISA. RESULTS: FTY720 decreased T cells in the peripheral blood, and increased T cells in the mediastinal lymph nodes. However, FTY720 treatment resulted in no change in PH or type 2 inflammation severity in mice sensitized and challenged with S. mansoni eggs, and the number of memory and effector CD4 T cells in the lung parenchyma was also unchanged. Notably, intraperitoneal Schistosoma egg sensitization alone resulted in a significant increase in intravascular lymphocytes and T cells, including memory T cells, although there was no significant change in parenchymal cell density, IL-4 or IL-13 expression, or PH. CONCLUSION: Blocking T cell migration did not suppress PH following Schistosoma egg challenge. Memory CD4 T cells, located in the lung intravascular space following egg sensitization, appear sufficient to cause type 2 inflammation and PH.

[Impact of drought on Oncomelania hupensis snails breeding in the Poyang Lake area].

OBJECTIVE: To examine the impact of arid climates on distribution of Oncomelania hupensis snails in the Poyang Lake area, so as to provide insights into precision control of O. hupensis snails in the Poyang Lake area. METHODS: O. hupensis snails-infested grass islands in Hukou County, Lianxi District and Lushan City in the northern Poyang Lake area, and Jinxian County, Nanchang County and Poyang County in the southern Poyang Lake area were selected as the study areas, and the occurrence of frames with living snails and the mean density of living snails were captured from snail surveys in the study areas in spring and autumn each year from 2006 to 2023. Five years 2007, 2011, 2013, 2019 and 2022 were selected as drought years, and the mean daily water levels were collected at the Xingzi hydrological station in the drought years, normal flow year (2012) and flood year (2020). The numbers of days with water levels ranging from the lower elevation (11 m) to the upper elevation (16 m) for snail survival and the numbers of days with water levels of 11 m and below were collected in the Poyang Lake area, and the changes of snail indicators were compared in different grass islands in the Poyang Lake area before and after drought. RESULTS: The numbers of days with water levels ranging from 11 to 16 m were 110, 88, 136 d and 125 d at the Xingzi hydrological station in four drought years 2007, 2011, 2013 and 2019, which were less than in the flow year and flood year, and the days with water levels of 11 m and below were 242, 277, 220 d and 198 d in four drought years 2007, 2011, 2013 and 2019, which were longer than in the flow year and flood year. A total of 416 snails-infested marshlands were surveyed in the Poyang Lake area from 2006 to 2021, and the survey marshlands accounted for 43.12% (307/712) and 46.98% (109/232) of total marshlands in the southern and northern Poyang Lake areas, respectively. The median occurrence of frames with living snails and mean density of living snails were 0.60% (interquartile range, 4.04%) and 0.010 1 snail/0.1 m2 (interquartile range, 0.076 1 snail/0.1 m2) in drought years, which were both lower than those [1.33% (5.19%) and 0.022 8 (0.098 9) snail/0.1 m2] in non-drought years (χ2= 42.170 and 44.911, both P values < 0.01). The proportion of grass islands with a continuous decline in snail indicators was higher in the southern Poyang Lake area than in the northern Poyang Lake area after the next year of drought (24.24% vs. 2.33%; χ2 = 10.633, P < 0.01), and the proportion of grass islands with rebounding snail indicators was higher in the northern Poyang Lake area than in the southern Poyang Lake area (53.49% vs. 15.76%; χ2 = 26.966, P < 0.01). A longitudinal analysis of snail indicators in marshlands with rebounding snail indicators after drought showed 1 to 5 years for return to pre-drought snail status, with a median of 2 (interquartile range, 1) years, and snail status was more likely to rebound if the occurrence of frames with living snails and the mean density of living snails were 2.11% and 0.025 5 snail/0.1 m2 and greater in snails-infested grass islands. CONCLUSIONS: Drought causes a remarkable decline in O. hupensis snail indicators in the Poyang Lake area, with a more remarkable impact in the southern Poyang Lake area, and 1 to 5 years are required for return to pre-drought snail status.

[Progress of interruption of schistosomiasis transmission and prospects in Yunnan Province].

Schistosomiasis was once hyper-endemic in Yunnan Province. Following concerted efforts for over 70 years, remarkable achievements have been made for schistosomiasis control in the province. In 2004, the Mid- and Long-term Plan for Schistosomiasis Prevention and Control in Yunnan Province was initiated in Yunnan Province, and the target for transmission control of schistosomiasis was achieved in the province in 2009. Following the subsequent implementation of the Outline for Key Projects in Integrated Schistosomiasis Control Program (2009-2015) and the 13th Five - year Plan for Schistosomiasis Control in Yunnan Province, no acute schistosomiasis had been identified in Yunnan Province for successive 12 years, and no local Schistosoma japonicum infections had been detected in humans, animals or Oncomelania hupensis snails for successive 6 years in the province by the end of 2020. The transmission of schistosomiasis was interrupted in Yunnan Province in 2020. This review summarizes the history of schistosomiasis, changes in schistosomiasis prevalence and progress of schistosomiasis control in Yunnan Province, and proposes the future priorities for schistosomiasis control in the province.

Inverse Correlation of Th2-Specific Cytokines with Hepatic Egg Burden in S. mansoni-Infected Hamsters.

Schistosomiasis, a parasitic disease caused by Schistosoma spp., affects more than 250 million people worldwide. S. mansoni in particular affects the gastrointestinal tract and, through its eggs, induces a Th2 immune response leading to granuloma formation. The relationship between egg load and immune response is poorly understood. We investigated whether the quantity of parasitic eggs influences the immune response in S. mansoni-infected hamsters. The hepatic and intestinal egg load was assessed, and cytokine expression as well as the expression of three major egg-derived proteins were analyzed in monosex- and bisex-infected animals by qRT-PCR. Statistical correlations between egg load or egg-derived factors Ipse/alpha-1, kappa-5, and omega-1, and the immune response were analyzed in liver and colon tissue. Surprisingly, no correlation of the Th1 cytokines with the hepatic egg load was observed, while the Th2 cytokines Il4, Il5, and Il13 showed an inverse correlation in the liver but not in the colon. A longer embryogenesis of the parasitic eggs in the liver could explain this correlation. This conclusion is supported by the lack of any correlation with immune response in the colon, as the intestinal passage of the eggs is limited to a few days.