Impact of human schistosomiasis in sub-Saharan Africa

Using zero-inflated and hurdle regression models to analyze schistosomiasis data of school children in the southern areas of Ghana

BACKGROUND

Schistosomiasis is a neglected disease prevalent in tropical and sub-tropical areas of the world, especially in Africa. Detecting the presence of the disease is based on the detection of the parasites in the stool or urine of children and adults. In such studies, typically, data collected on schistosomiasis infection includes information on many negative individuals leading to a high zero inflation. Thus, in practice, counts data with excessive zeros are common. However, the purpose of this analysis is to apply statistical models to the count data and evaluate their performance and results.

METHODS

This is a secondary analysis of previously collected data. As part of a modelling process, a comparison of the Poisson regression, negative binomial regression and their associated zero inflated and hurdle models were used to determine which offered the best fit to the count data.

RESULTS

Overall, 94.1% of the study participants did not have any schistosomiasis eggs out of 1345 people tested, resulting in a high zero inflation. The performance of the negative binomial regression models (hurdle negative binomial (HNB), zero inflated negative binomial (ZINB) and the standard negative binomial) were better than the Poisson-based regression models (Poisson, zero inflated Poisson, hurdle Poisson). The best models were the ZINB and HNB and their performances were indistinguishable according to information-based criteria test values.

CONCLUSION

The zero-inflated negative binomial and hurdle negative binomial models were found to be the most satisfactory fit for modelling the over-dispersed zero inflated count data and are recommended for use in future statistical modelling analyses.

Knowledge and management of female genital schistosomiasis in sub-Saharan Africa: A scoping review protocol

Background

Approximately 20 to 120 million women of reproductive age worldwide are thought to be affected by female genital schistosomiasis (FGS). It is a preventable manifestation of schistosomiasis in adolescent girls and women, which remains underreported, underdiagnosed, or misdiagnosed, and largely untreated.

Objective

This study aimed to map evidence on the knowledge and management of FGS from 1950 to 2022 in sub-Saharan Africa.

Method

The Arksey and O'Malley and Levac et al. framework suggestions and a guideline from Joanna Briggs Institute will be employed. Search for literature will be in PubMed, Scopus, Cochrane, Web of Science, MEDLINE via PubMed, and Google Scholar from 1950 to 2022 for useful published research articles using key phrases or search terms and grey literature with limitations for studies conducted in sub-Saharan Africa. Two reviewers will screen the articles. Kappa coefficients by Cohen statistics will be computed for inter-screener agreement, and the selected articles will be evaluated using Mixed Method Appraisal Tool (MMAT).

Results

The researchers will map and explore the evidence of the knowledge and management of FGS in the subregion. The years of publications, countries of study, and settings will be reported, and the identified research gaps will be reported.

Conclusion

The researchers anticipate that this study will determine and map the evidence on the knowledge and management of FGS in sub-Saharan Africa; identify knowledge and management gaps, and direct future research.

Contribution

This study will add to the literature on FGS and direct future research regarding the knowledge and management of FGS.

A comprehensive exploration of schistosomiasis: Global impact, molecular characterization, drug discovery, artificial intelligence and future prospects

Schistosomiasis, one of the neglected tropical diseases which affects both humans and animals, is caused by trematode worms of the genus Schistosoma. The disease is caused by several species of Schistosoma which affect several organs such as urethra, liver, bladder, intestines, skin and bile ducts. The life cycle of the disease involves an intermediate host (snail) and a mammalian host. It affects people who are in close proximity to water bodies where the intermediate host is abundant. Common clinical manifestations of the disease at various stages include fever, chills, headache, cough, dysuria, hyperplasia and hydronephrosis. To date, most of the control strategies are dependent on effective diagnosis, chemotherapy and public health education on the biology of the vectors and parasites. Microscopy (Kato-Katz) is considered the golden standard for the detection of the parasite, while praziquantel is the drug of choice for the mass treatment of the disease since no vaccines have yet been developed. Most of the previous reviews on schistosomiasis have concentrated on epidemiology, life cycle, diagnosis, control and treatment. Thus, a comprehensive review that is in tune with modern developments is needed. Here, we extend this domain to cover historical perspectives, global impact, symptoms and detection, biochemical and molecular characterization, gene therapy, current drugs and vaccine status. We also discuss the prospects of using plants as potential and alternative sources of novel anti-schistosomal agents. Furthermore, we highlight advanced molecular techniques, imaging and artificial intelligence that may be useful in the future detection and treatment of the disease. Overall, the proper detection of schistosomiasis using state-of-the-art tools and techniques, as well as development of vaccines or new anti-schistosomal drugs may aid in the elimination of the disease.

Leveraging wastewater-based epidemiology to monitor the spread of neglected tropical diseases in African communities

Neglected tropical diseases continue to cause a significant burden worldwide, with Africa accounting for more than one-third of the global burden. Over the past decade, progress has been made in eliminating, controlling, and eradicating these diseases in Africa. By December 2022, 47 out of 54 African countries had eliminated at least one neglected tropical disease, and more countries were close to achieving this milestone. Between 2020 and 2021, there was an 80 million reduction in people requiring intervention. However, continued efforts are needed to manage neglected tropical diseases and address their social and economic burden, as they deepen marginalisation and stigmatisation. Wastewater-based epidemiology involves analyzing wastewater to detect and quantify biomarkers of disease-causing pathogens. This approach can complement current disease surveillance systems in Africa and provide an additional layer of information for monitoring disease spread and detecting outbreaks. This is particularly important in Africa due to limited traditional surveillance methods. Wastewater-based epidemiology also provides a tsunami-like warning system for neglected tropical disease outbreaks and can facilitate timely intervention and optimised resource allocation, providing an unbiased reflection of the community's health compared to traditional surveillance systems. In this review, we highlight the potential of wastewater-based epidemiology as an innovative approach for monitoring neglected tropical disease transmission within African communities and improving existing surveillance systems. Our analysis shows that wastewater-based epidemiology can enhance surveillance of neglected tropical diseases in Africa, improving early detection and management of Buruli ulcers, hookworm infections, ascariasis, schistosomiasis, dengue, chikungunya, echinococcosis, rabies, and cysticercosis for better disease control.

Gut microbiota and immune profiling of microbiota-humanised versus wildtype mouse models of hepatointestinal schistosomiasis

Mounting evidence of the occurrence of direct and indirect interactions between the human blood fluke, Schistosoma mansoni, and the gut microbiota of rodent models raises questions on the potential role(s) of the latter in the pathophysiology of hepatointestinal schistosomiasis. However, substantial differences in both the composition and function between the gut microbiota of laboratory rodents and that of humans hinders an in-depth understanding of the significance of such interactions for human schistosomiasis. Taking advantage of the availability of a human microbiota-associated mouse model (HMA), we have previously highlighted differences in infection-associated changes in gut microbiota composition between HMA and wildtype (WT) mice. To further explore the dynamics of schistosome-microbiota relationships in HMA mice, in this study we (i) characterize qualitative and quantitative changes in gut microbiota composition of a distinct line of HMA mice (D2 HMA) infected with S. mansoni prior to and following the onset of parasite egg production; (ii) profile local and systemic immune responses against the parasite in HMA as well as WT mice and (iii) assess levels of faecal inflammatory markers and occult blood as indirect measures of gut tissue damage. We show that patent S. mansoni infection is associated with reduced bacterial alpha diversity in the gut of D2 HMA mice, alongside expansion of hydrogen sulphide-producing bacteria. Similar systemic humoral responses against S. mansoni in WT and D2 HMA mice, as well as levels of faecal lipocalin and markers of alternatively activated macrophages, suggest that these are independent of baseline gut microbiota composition. Qualitative comparative analyses between faecal microbial profiles of S. mansoni-infected WT and distinct lines of HMA mice reveal that, while infection-induced alterations of the gut microbiota composition are highly dependent on the baseline flora, bile acid composition and metabolism may represent key elements of schistosome-microbiota interactions through the gut-liver axis.

Urinary schistosomiasis and anemia among school-aged children from southwestern Nigeria

Schistosomiasis and anemia, are one of the leading global public health problem among children between age 5 and 14 years in marginalized settings. In this study, we provide prevalence and intensity data for both conditions in three southwestern states of Nigeria, where such are lacking. Epidemiological assessment involving parasitological analysis of urine and blood samples was conducted among 1783 consenting school-aged children in Ondo, Osun, Ekiti States of Nigeria. Participants' age and sex data were obtained using field forms, and statistical analysis was performed in R software with a significance level of 95%. An overall prevalence of 26.8% and 29.5% was recorded for urinary schistosomiasis and anemia, respectively. Prevalence varied by location with (40.3% and 29.8%) in Ondo (34.4% and 37.5%) in Osun and (13.4% and 20.9%) in Ekiti for urinary schistosomiasis and anemia, respectively (p=0.00). Schistosoma infections were found among males (28.7%, p=0.05) and children between the age 9-11 years (30.0%, p=0.01). About 36% of children with anemia was also infected with schistosomiasis. Children who were positive for schistosomiasis (OR:1.51; 95% CI: 1.19, 1.93; p=0.001) and between the age category 15-16 years, (OR:1.86; 95% CI: 1.12, 3.09; p<0.05) were twice likely to become anemic. Our findings have shown that children infected with schistosomiasis are twice likely to become anemic than those without infection. It is important to complement ongoing MDA programmes targeted at schistosomiasis with nutrition intervention programs for example micronutrient supplementation for better impact and cost-effectiveness.

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

BACKGROUND

Community 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.

METHODS

This 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.

RESULTS

Among 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.

CONCLUSIONS

Despite 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.

Awareness towards urinary schistosomiasis and its relation with active infection among primary school pupils and students in North Kordofan state, Sudan 2022

Objectives

This study intends to evaluate the prevalence of active Schistosomiasis in school children, as well as their awareness, attitude, and behavior towards the illness in El-Rahad province.

Methods

This facility-based analytical cross-sectional study among 495 primary school children aged seven to 13 in five villages; Structured and pre-tested questionnaires were used to collect the data in face-to-face interviews, in addition, urine samples were collected from each pupil and then assessed microscopically for S. Haematobium eggs Presence. Data was analyzed using SPSS version 25.0.

Results

A total of 424 primary school students participated in the study. Almost all the students (96%) had poor knowledge about urinary schistosomiasis. In general, 100% of the students had poor practices. Attitude revealed that females have lower chance of having the infection than their male counterparts. About 27% (n = 115) of them had active urinary schistosomiasis infection at the time of the study.

Conclusion

The study revealed poor level of awareness and knowledge, positive attitude, and poor practices among primary school students. There was also high level of active infection among participants.

In Silico Comparison of Bioactive Compounds Characterized from Azadirachta indica with an FDA-Approved Drug against Schistosomal Agents: New Insight into Schistosomiasis Treatment

The burden of human schistosomiasis, a known but neglected tropical disease in Sub-Saharan Africa, has been worrisome in recent years. It is becoming increasingly difficult to tackle schistosomiasis with praziquantel, a drug known to be effective against all Schistosoma species, due to reports of reduced efficacy and resistance. Therefore, this study seeks to investigate the antischistosomal potential of phytochemicals from Azadirachta indica against proteins that have been implicated as druggable targets for the treatment of schistosomiasis using computational techniques. In this study, sixty-three (63) previously isolated and characterized phytochemicals from A. indica were identified from the literature and retrieved from the PubChem database. In silico screening was conducted to assess the inhibitory potential of these phytochemicals against three receptors (Schistosoma mansoni Thioredoxin glutathione reductase, dihydroorotate dehydrogenase, and Arginase) that may serve as therapeutic targets for schistosomiasis treatment. Molecular docking, ADMET prediction, ligand interaction, MMGBSA, and molecular dynamics simulation of the hit compounds were conducted using the Schrodinger molecular drug discovery suite. The results show that Andrographolide possesses a satisfactory pharmacokinetic profile, does not violate the Lipinski rule of five, binds with favourable affinity with the receptors, and interacts with key amino acids at the active site. Importantly, its interaction with dihydroorotate dehydrogenase, an enzyme responsible for the catalysis of the de novo pyrimidine nucleotide biosynthetic pathway rate-limiting step, shows a glide score and MMGBSA of -10.19 and -45.75 Kcal/mol, respectively. In addition, the MD simulation shows its stability at the active site of the receptor. Overall, this study revealed that Andrographolide from Azadirachta indica could serve as a potential lead compound for the development of an anti-schistosomal drug.

Endemic status of urogenital schistosomiasis and the efficacy of a single-dose praziquantel treatment in unmapped rural farming communities in Oyo East Local Government Area, Oyo State, Nigeria

BACKGROUND

Schistosomiasis is endemic in Nigeria, and the treatment is largely concentrated on children enrolled in schools. Consequently, the coverage of non-enrolled school-aged children is often neglected. Ajagba and Awosan are two communities in Nigeria that have never had any control intervention. Hence, this survey was designed to determine the endemicity of urogenital schistosomiasis and to evaluate the efficacy of a single-dose praziquantel in the communities.

METHODS

Urine sample (10 mL) of each participant from Ajagba and Awosan communities was filtered through 12μm polycarbonate filter. The filter was placed on a microscope slide, and stained with a drop of 1% Lugol iodine solution. The stained slides were examined under the microscope and the numbers of S. haematobium eggs were counted. Water contact sites were searched for snail hosts and the snails collected were shed for Schistosoma cercariae. Data were analyzed using SPSS version 24.0 and the significance level was set at 95%.

RESULTS

The overall prevalence of infection in the Ajagba community was 45.6% with a mean intensity of 61.1 ± 144.5 eggs/10 mL of urine, while the prevalence of infection in the Awosan community was 5.7% with a mean intensity of 1.4 ± 6.8 eggs/10 mL of urine. The school-aged children had a prevalence and mean intensity of infection of 73.1% and 111.6 ± 177.9 eggs/10 mL of urine, respectively. Following treatment, women had a higher egg reduction rate than men (p = 0.0283). Bulinus globosus were found in Ajagba but not in Awosan, with 5.7% shedding Schistosoma spp, cercariae.

CONCLUSION

Urogenital schistosomiasis was hyperendemic in the Ajagba community, and hypoendemic in the Awosan community. The presence of Bulinus globosus supported the transmission of the schistosomiasis in the Ajagba community. Communities where schistosomiasis is still actively transmitted in Nigeria should be identified for effective intervention through the MDA programs.

An automated slide scanning system for membrane filter imaging in diagnosis of urogenital schistosomiasis

Traditionally, automated slide scanning involves capturing a rectangular grid of field-of-view (FoV) images which can be stitched together to create whole slide images, while the autofocusing algorithm captures a focal stack of images to determine the best in-focus image. However, these methods can be time-consuming due to the need for X-, Y- and Z-axis movements of the digital microscope while capturing multiple FoV images. In this paper, we propose a solution to minimise these redundancies by presenting an optimal procedure for automated slide scanning of circular membrane filters on a glass slide. We achieve this by following an optimal path in the sample plane, ensuring that only FoVs overlapping the filter membrane are captured. To capture the best in-focus FoV image, we utilise a hill-climbing approach that tracks the peak of the mean of Gaussian gradient of the captured FoVs images along the Z-axis. We implemented this procedure to optimise the efficiency of the Schistoscope, an automated digital microscope developed to diagnose urogenital schistosomiasis by imaging Schistosoma haematobium eggs on 13 or 25 mm membrane filters. Our improved method reduces the automated slide scanning time by 63.18% and 72.52% for the respective filter sizes. This advancement greatly supports the practicality of the Schistoscope in large-scale schistosomiasis monitoring and evaluation programs in endemic regions. This will save time, resources and also accelerate generation of data that is critical in achieving the targets for schistosomiasis elimination.

Prevalence of intestinal parasitic infections and associated risk factors among patients attending Debarq Primary Hospital, northwest Ethiopia

Intestinal parasitic infections (IPIs) are major public health problems in developing countries. This study was conducted to determine the prevalence and associated risk factors of IPIs at Debarq Primary Hospital in northwest Ethiopia. A health facility-based cross-sectional study was conducted from March 2022 to June 2022. The study participants were recruited from patients who visited Debarq Primary Hospital during the study period. Stool samples were collected from each participant and examined for intestinal parasites using direct wet-mount and formal-ether concentration techniques. Socio-demographic data were collected using a structured questionnaire. Out of 422 individuals examined, 33.64% were infected with at least one intestinal parasite species. Entamoeba histolytica/dispar, Giardia intestinalis, Ascaris lumbricoides, and hookworm were found in 12.79%, 8.53%, 7.10%, and 1.65% of the participants, respectively. Double and triple parasite infections were found in 2.37% and 0.23% of the participants, respectively. A habit of eating unwashed vegetables (Adjusted odds ratio (AOR) = 9.98, 95% confidence interval (CI) = 2.68-37.14) and low income (AOR = 6.66, 95% CI = 1.87-23.70) were associated with increased odds of IPIs. Participants with a habit of hand washing after using the toilet had 0.05 (95% CI = 0.13-0.22) lower odds of IPIs than those who did not. In conclusion, IPIs are common among Debarq Primary Hospital patients and are associated with factors such as low income, not washing hands after using the toilet, and eating unwashed vegetation, necessitating control and prevention efforts in the study area that include health education and the provision and use of sanitary facilities.

Exploring the Role of Community Involvement in Reducing the Burden of Schistosomiasis and Other Neglected Tropical Diseases in Malawi: Where are We in the Fight Against Neglected Tropical Diseases?

Schistosomiasis has been endemic in Malawi since 1947. Despite the longevity of endemicity of the disease, it still maintains a high burden in Malawi. This could be attributed to insufficient coverage of preventive and therapeutic mass drug administration (MDA) which mainly targets school-aged children, leaving out adults who also bear a high burden of the disease. Additionally, despite well documented impact of community involvement in boosting up the effectiveness of health programmes, there is minimal community involvement in schistosomiasis control and prevention programmes. Therefore, this perspective seeks to discuss the historical background of schistosomiasis in Malawi, gaps in community engagement and participation and suggest ways of enhancing the role of the community in prevention and control programmes. Amongst other challenges, the control programmes are centralised, leading to minimal input at the district and community level as well as low awareness of schistosomiasis control and prevention methods at the community level. It is of utmost significance therefore to provide comprehensive schistosomiasis health education to the communities and devise a thorough outline of the specific roles and responsibilities of all stakeholders including community members in the fight against schistosomiasis and other neglected tropical diseases.

Validation of artificial intelligence-based digital microscopy for automated detection of Schistosoma haematobium eggs in urine in Gabon

INTRODUCTION

Schistosomiasis is a significant public health concern, especially in Sub-Saharan Africa. Conventional microscopy is the standard diagnostic method in resource-limited settings, but with limitations, such as the need for expert microscopists. An automated digital microscope with artificial intelligence (Schistoscope), offers a potential solution. This field study aimed to validate the diagnostic performance of the Schistoscope for detecting and quantifying Schistosoma haematobium eggs in urine compared to conventional microscopy and to a composite reference standard (CRS) consisting of real-time PCR and the up-converting particle (UCP) lateral flow (LF) test for the detection of schistosome circulating anodic antigen (CAA).

METHODS

Based on a non-inferiority concept, the Schistoscope was evaluated in two parts: study A, consisting of 339 freshly collected urine samples and study B, consisting of 798 fresh urine samples that were also banked as slides for analysis with the Schistoscope. In both studies, the Schistoscope, conventional microscopy, real-time PCR and UCP-LF CAA were performed and samples with all the diagnostic test results were included in the analysis. All diagnostic procedures were performed in a laboratory located in a rural area of Gabon, endemic for S. haematobium.

RESULTS

In study A and B, the Schistoscope demonstrated a sensitivity of 83.1% and 96.3% compared to conventional microscopy, and 62.9% and 78.0% compared to the CRS. The sensitivity of conventional microscopy in study A and B compared to the CRS was 61.9% and 75.2%, respectively, comparable to the Schistoscope. The specificity of the Schistoscope in study A (78.8%) was significantly lower than that of conventional microscopy (96.4%) based on the CRS but comparable in study B (90.9% and 98.0%, respectively).

CONCLUSION

Overall, the performance of the Schistoscope was non-inferior to conventional microscopy with a comparable sensitivity, although the specificity varied. The Schistoscope shows promising diagnostic accuracy, particularly for samples with moderate to higher infection intensities as well as for banked sample slides, highlighting the potential for retrospective analysis in resource-limited settings.

TRIAL REGISTRATION

NCT04505046 ClinicalTrials.gov.

Efficacy and safety of praziquantel treatment against Schistosoma mansoni infection among pre-school age children in southern Ethiopia

BACKGROUND

Preventive chemotherapy with a single dose of praziquantel given to an all-at-risk population through mass drug administration is the cornerstone intervention to control and eliminate schistosomiasis as a public health problem. This intervention mainly targets school age children, and pre-school age children (pre-SAC) are excluded from receiving preventive chemotherapy, partly due to scarcity of data on praziquantel treatment outcomes.

METHODS

We conducted active efficacy and safety surveillance of praziquantel treatment among 240 Schistosoma mansoni-infected pre-SAC who received a single dose of praziquantel (40 mg/kg) in southern Ethiopia. The study outcomes were egg reduction rates (ERR) and cure rates (CRs) four weeks after treatment using the Kato-Katz technique and treatment-associated adverse events (AEs) that occurred within 8 days post-treatment.

RESULTS

The overall ERR was 93.3% (WHO reference threshold ≥ 90%), while the CR was 85.2% (95% CI = 80.0-89.5%). Baseline S. mansoni infection intensity was significantly associated with CRs, 100% among light infected than moderate (83.4%) or heavy (29.4%) infected children. An increase of 100 in baseline S. mansoni egg count per gram of stool resulted in a 26% (95% CI: 17%, 34%) reduction in the odds of cure. The incidence of experiencing at least one type of AE was 23.1% (95% CI: 18.0%, 29.0%). Stomachache, diarrhea, and nausea were the most common AEs. AEs were mild-to-moderate grade and transient. Pre-treatment moderate (ARR = 3.2, 95% CI: 1.69, 6.14) or heavy infection intensity (ARR = 6.5, 95% CI: 3.62, 11.52) was a significant predictor of AEs (p < 0.001). Sex, age, or soil-transmitted helminth coinfections were not significant predictors of CR or AEs.

CONCLUSIONS

Single-dose praziquantel is tolerable and effective against S. mansoni infection among pre-SAC, and associated AEs are mostly mild-to-moderate and transient. However, the reduced CR in heavily infected and AEs in one-fourth of S. mansoni-infected pre-SAC underscores the need for safety and efficacy monitoring, especially in moderate-to-high infection settings. Integrating pre-SACs in the national deworming programs is recommended to accelerate the elimination of schistosomiasis as a public health problem.

Evaluating the Prevalence and Risk Factors of Schistosomiasis Amongst School-Aged Children in Low- and Middle-Income Communities: Ehlanzeni District Municipality, South Africa, 2015-2021

This study aimed to assess the prevalence and identify risk factors of schistosomiasis among school-aged children in low- and middle-income communities. A retrospective cross-sectional study was conducted to review patient records of school-age children. Data on gender, age, sub-district, area residing in, patient status, history of bilharzia, presence of blood in the urine, and schistosomiasis diagnoses were collected. The data were analyzed using IBM Statistical Package for the Social Sciences (SPSS) version 27. Logistic regression was employed to determine the factors associated with schistosomiasis. The overall prevalence of schistosomiasis in the study population was 75%, with higher prevalence observed among male children (89%), children aged between 10 and 14 years (59%), urban areas (51%), and rural-dominated districts, particularly Bushbuckridge (42%) and City of Mbombela (51%). Age, especially 10-14 years old (p ˂ 0.01; 95%CI: 1.98-2.29), a history of bilharzia (p = 0.01; 95%CI: 1.15-1.96), and the presence of blood in urine (p ˂ 0.01; 95%CI: 2.02-2.40) were significantly associated with schistosomiasis while being a female child was found to be a protective factor (AOR: 0.35; CI 0.35-0.41). This study underscores the importance of implementing robust screening procedures and the necessity for health education to mitigate the high prevalence of schistosomiasis and prevent its further spread.

Human schistosomiasis in Nigeria: present status, diagnosis, chemotherapy, and herbal medicines

Schistosomiasis is a neglected tropical disease caused by a parasitic, trematode blood fluke of the genus Schistosoma. With 20 million people infected, mostly due to Schistosoma haematobium, Nigeria has the highest burden of schistosomiasis in the world. We review the status of human schistosomiasis in Nigeria regarding its distribution, prevalence, diagnosis, prevention, orthodox and traditional treatments, as well as snail control strategies. Of the country's 36 states, the highest disease prevalence is found in Lagos State, but at a geo-political zonal level, the northwest is the most endemic. The predominantly used diagnostic techniques are based on microscopy. Other methods such as antibody-based serological assays and DNA detection methods are rarely employed. Possible biomarkers of disease have been identified in fecal and blood samples from patients. With respect to preventive chemotherapy, mass drug administration with praziquantel as well as individual studies with artemisinin or albendazole have been reported in 11 out of the 36 states with cure rates between 51.1 and 100%. Also, Nigerian medicinal plants have been traditionally used as anti-schistosomal agents or molluscicides, of which Tetrapleura tetraptera (Oshosho, aridan, Aidan fruit), Carica papaya (Gwanda, Ìbẹ́pẹ, Pawpaw), Borreria verticillata (Karya garma, Irawo-ile, African borreria), and Calliandra portoricensis (Tude, Oga, corpse awakener) are most common in the scientific literature. We conclude that the high endemicity of the disease in Nigeria is associated with the limited application of various diagnostic tools and preventive chemotherapy efforts as well as poor knowledge, attitudes, and practices (KAP). Nonetheless, the country could serve as a scientific base in the discovery of biomarkers, as well as novel plant-derived schistosomicides and molluscicides.

Liposomal IL-22 ameliorates liver fibrosis through miR-let7a/STAT3 signaling in mice

The therapeutic effect of liposomal IL-22 versus non-liposomal IL-22 on liver fibrosis was investigated. IL-22 (5 µg/ml) was incorporated into negative charged liposomes. Schistosoma mansoni infected mice were treated with liposomal IL-22 for either 7 or 14 days before decapitation. Liver and spleen were removed and splenocytes were isolated for in vitro investigations. TNF-α, IL-17, IL-22 and IgE levels were assessed. Hepatic granulomas were counted, granuloma index and its developmental stages were calculated. Hepatic expressions of STAT3, β-catenin and let-7a miRNA were evaluated. Liposomal IL-22 size was clustered around 425.9 ± 58.0 nm with negative zeta potential (-18.8 ± 1.3 mV). After 14 days, 65.5% of IL-22 was released from liposomal IL-22 as was gradually observed in vitro. Liposomal IL-22 significantly (p < 0.05) decreased IL-17 level (-33.1%) of healthy splenocytes compared to non-liposomal IL-22. In vivo therapeutic effect of liposomal IL-22 revealed a significant (p < 0.05) decrease in hepatic granuloma index (-22.1%) and levels of TNF-α (-49.2%) and IL-17 (-57.3%), but a marked increase in IL-22 (64.2%) and IgE (196.1%) levels comparing to non-liposomal IL-22. Three developmental stages of hepatic granuloma (NE, EP, and P) were observed in liposomal and non-liposomal IL-22 groups (79.6 ± 1.7 and 81.8 ± 8.7, respectively, P < 0.05), with higher relative frequency of EP stage. Additionally, liposomal IL-22 treatment increased hepatic expression of STAT3 (21.7 fold change) and let-7a (3.6 fold change) and reduced β-catenin expression (0.6 fold change) compared to healthy mice. Conclusively, liposomal IL-22 seems more effective in the treatment of liver fibrosis resulting from S. mansoni infection than non-liposomal IL-22.

Praziquantel efficacy, urinary and intestinal schistosomiasis reinfection - a systematic review

Praziquantel (PZQ) has been extensively used as the drug of choice for the treatment of schistosomiasis on account of its safety and effectiveness against all major forms of schistosomiasis. However, low cure rate, reduced susceptibility of Schistosoma mansoni to PZQ and treatment failures in S. haematobium infections have been reported, raising concerns about its efficacy. Using the search terms, 'praziquantel efficacy, schistosomiasis, school children, reinfection' as well as defined inclusion criteria, and guided by the PRISMA guidelines, articles from 2001 to 2022 were selected from the PubMed and Google Scholar databases and reviewed to assess their importance to the research question. This review assessed the efficacy of PZQ against schistosomiasis and reinfection rates following treatment of Schistosoma infections in children. Majority of both intestinal and urinary schistosomiasis studies reported comparable egg reduction rates (ERRs) of 94.2% to 99.9% and 91.9% to 98%, respectively. However, ERRs suggestive of sub-optimal PZQ efficacy as well as generally high and comparable cure rates for intestinal (81.2%-99.1%) and urinary (79%-93.7%) schistosomiasis studies were reported. Schistosomiasis reinfection rates varied widely for urinary (8.1%-39.6%) and intestinal (13.9%-63.4%) studies within eight to 28 weeks following PZQ treatment. Praziquantel treatment of urinary and intestinal schistosomiasis should be accompanied by the provision of potable water, toilet, and recreational facilities to reduce reinfection and egg reduction rates and increase cure rate to expedite schistosomiasis elimination.

Efficacy of Single-Dose Praziquantel for the Treatment of Schistosoma mansoni Infections among School Children in Rwanda

Preventive chemotherapy with single-dose praziquantel is the WHO-recommended intervention strategy to eliminate schistosomiasis as a public health problem in endemic countries. Surveillance of drugs used in mass drug administration (MDA) programs is recommended to evaluate its effectiveness in reducing transmissions. After a decade-long implementation of a school-based MDA program in Rwanda, we conducted efficacy surveillance of single-dose praziquantel MDA against S. mansoni infection. Two weeks before MDA, stool examinations were performed to screen MDA-eligible school children (n = 4998) for S. mansoni infection using the Kato-Katz technique, and 265 (6.5%) children tested positive for the infection. All children received praziquantel and albendazole as preventive chemotherapy through the MDA campaign. Infected children were enrolled and followed for efficacy monitoring, and stool examination was repeated after three weeks post-MDA (n = 188). Before treatment, 173 (92%) had a light infection, and 15 (8%) had a moderate infection intensity. The primary and secondary outcomes were parasitological cure and egg reduction rates at three weeks post-treatment. The overall cure and egg reduction rates for S. mansoni infection were 97.9% (95% CI = 94.6-99.4) and 97.02%, respectively. Among the 173 children with light infection intensity, 170 (98.3%, 95% CI = 95.0-99.6) were cured, and among the 15 children who had moderate infection intensity, 14 (93.3%) were cured. No significant association between cure rate and pre-treatment infection intensity was observed. We conclude that single-dose praziquantel is efficacious against light-to-moderate S. mansoni infection. Preventive chemotherapy with praziquantel effectively reduces schistosome reservoirs and transmission among school-age children.

In Vitro Cercaricidal Activity, Acute Toxicity, and GC/MS Analysis of Some Selected Ghanaian Medicinal Plants

Schistosomiasis is a human parasitic disease caused by the Schistosoma species and is recognised in public health as second to malaria in terms of its socioeconomic impact on humans. Four local plants native to many tribes in Ghana and known for their medicinal properties against some diseases were assessed for their cercaricidal activity against Schistosoma mansoni cercariae. The plants, namely, Newbouldia laevis stem bark (NLSB), Spathodea campanulata stem bark (SCSB), Momordica charantia leaves (MCL), and Ocimum viride leaves (OVL), were extracted for their active metabolites using methanol. Preliminary phytochemical screening was carried out on all plant extracts and powdered samples. The crude extracts were tested against S. mansoni cercariae in vitro using Balanites aegyptiaca as the positive control. The percentage of mortalities for each extract was recorded. Gas chromatography/mass spectrometry (GC/MS) analysis was conducted on all the plant extracts. Phytochemical analysis revealed the presence of saponins, glycosides, triterpenoids, sterols, alkaloids, flavonoids, and tannins in almost all the extracts. GC/MS analysis showed the presence of medicinally important active volatile compounds in each extract such as thymol, n-hexadecanoic acid, phytol, and maltol. All four plants showed relatively different levels of activity against S. mansoni cercariae at different times and concentrations. The LC50 values of the plant extracts were determined at the end of the assay. At 240 min, NLSB, SCSB, MCL, and OVL extracts had LC50 values of 487.564, 429.898, 197.696, and 0.129 μg/mL, respectively. Hence, this study revealed the potency of Ocimum viride leaves, Momordica charantia leaves, Spathodea campanulata stem bark, and Newbouldia laevis stem bark against S. mansoni. These plants could therefore be exploited as possible candidates for curbing schistosomiasis.

Severity of Schistosoma haematobium co-infection with malaria in school-children is potentially modulated by host CD14 gene variants

OBJECTIVE

Schistosomiasis remains a chronic disease of global importance, especially in many rural areas of the world where co-infection with Plasmodium falciparum is common. It is critical to decipher the role of single or co-infected disease scenarios on immune system regulation in such individuals and how such co-infections can either ameliorate or complicate immune response and the consequent disease outcome. First, 10 ml of urine samples, collected between 10:00 am and 2:00 pm, was filtered for diagnosis of schistosomiasis, while egg count, indicative of disease severity, was determined by microscopy. Furthermore, genomic DNA samples extracted from dried blood spots collected on filter paper from one hundred and forty-four Schistosoma haematobium-infected school-children was tested for P. falciparum parasite positivity by an allele-specific nested-PCR analysis of merozoite surface protein (msp)-1 and -2 genes and a real-time PCR assay. In addition, among P. falciparum parasite-positive individuals, we carried out a Taqman SNP genotyping assay to extrapolate the effect of host CD14 (-159 C/T; rs2569190) genetic variants on schistosome egg count.

RESULTS

Of the 144 individuals recruited, P. falciparum parasite positivity with msp-1 gene were 34%, 43% and 55% for MAD20, RO33 and K1 alleles respectively. Of the co-infected individuals, CD14 genetic variants ranged from 18.8% vs 21.5%, 33.3% vs 44.4%, 9.7% vs 11.8% for single versus schistosome co-infection for the wild type (CC), heterozygous (CT) and mutant (TT) variants respectively. Though the mean egg count for co-infected individuals with CD14 wild type (33.7 eggs per 10 ml of urine) and heterozygote variants (37.5 eggs per 10 ml of urine) were lower than that of schistosome infection alone (52.48 and 48.08 eggs/10 ml of urine respectively), it lacked statistical significance (p-value 0.12 and 0.29), possibly reflecting the benefit of the CD14 activation in schistosome plus malaria co-infection and not schistosome infection alone. In addition, the lower mean egg count in co-infected individuals reveal the benefit of downstream Th1 immune response mitigated by CD14 innate activation that is absent in schistosome infection alone.

Modeling the transmission phenomena of water-borne disease with non-singular and non-local kernel

Drinking or recreating water that has been polluted with disease-causing organisms or pathogens is what causes waterborne infections. It should be noted that many water-borne infections can also transmit from person to person, by contact with animals or their surroundings, or by ingesting tainted food or beverages. Schistosomiasis is a water-borne infection found in different areas of the globe. Mostly people with this viral infection live in Africa with limited resources and medications. Therefore, investigation of this infection is significant to reduce its economic burden on the society. We formulated a novel epidemic model for schistosomiasis water-borne infection with the help of the Atangana-Baleanu derivative. The rudimentary theory of fractional-calculus has been presented for the analysis of our system. We start by looking at the model solution's non-negativity and uniqueness. The basic reproduction number and equilibria of the hypothesized water-borne infection model are next evaluated. Local stability of the infection-free steady-state has been established through Jacobian matrix method for R 0 < 1 . In addition, the suggested model's solution is calculated using an iterative technique. Finally, we give numerical simulations for various input values to illustrate the impact of memory index and other input factors of the system. Our findings showed the influence of input parameters on the dynamical behaviour of the schistosomiasis infection. The results demonstrate the importance and persuasive behaviour of fractional order, and reveal that fractional memory effects in the model seem to be a good fit for this type of findings.

Molecular detection of Fasciola, Schistosoma and Paramphistomum species from freshwater snails occurring in Gauteng and Free State provinces, South Africa

Trematodiases are diseases caused by snail-borne trematode parasites that infect both animals and humans. Fascioliasis, schistosomiasis and paramphistomosis are some of these diseases and they affect millions of livestock, leading to significant economic losses. The aim of the study was to document freshwater snails occurring in selected study sites in the Free State and Gauteng provinces as well as identify and detect larval trematodes that they harbour. Samples were collected from a total of five study sites within two provinces of South Africa. Morphological features were used to identify snail species and were further confirmed genetically by polymerase chain reaction (PCR), sequencing and phylogenetic analysis. The larval trematodes were also detected by PCR, PCR-Restriction Length Fragment Polymorphism (PCR-RLFP), sequencing and phylogenetic analysis. A total of 887 freshwater snails were collected from Free State (n = 343) and Gauteng (n = 544). Five different genera of snails as well as species in the Succineidae family were documented. The snails in descending order of abundance were identified as: Physa (P.) spp. (51%), Succineidae spp. (20%), Galba (G.) truncatula (12%), Pseudosuccinea (Ps.) columella (10%), Planorbella (Pl.) duryi (6%) and Bulinus (B.) truncatus (1%). Approximately 272 DNA pools were created for genetic identification of snails and detection of trematode parasites. Schistosoma species were not detected from any of the snail species. A total prevalence of 46% was obtained for Fasciola hepatica in the identified snail species across all study sites. Overall, the highest prevalence of F. hepatica was obtained in Physa species (24%), whilst the lowest was observed in B. truncatus snails (1%). Forty three percent (43%) of the snail samples were PCR positive for Paramphistomum DNA. This is the first report of P. mexicana in South Africa. Fasciola hepatica was confirmed from all obtained snail species per study site. This is the first reported detection of F. hepatica in Pl. duryi and P. mexicana snails as well as the first confirmation of natural infection from P. acuta in South Africa.

Test-Treat-Track-Test-Treat Strategy for Control of Schistosomiasis in Two Low-Prevalence Villages in Northwestern Tanzania

Mass drug administration of praziquantel becomes a less attractive strategy for elimination of schistosomiasis in low-prevalence areas due to cost implications and low treatment compliance. We aimed to determine the feasibility of a Test-Treat-Track-Test-Treat (5T) strategy in two low-prevalence villages; the 5T strategy has been successfully implemented in diseases such as malaria. A total of 200 school children aged 6-12 years were randomly selected from two schools and tested for Schistosoma mansoni infection using the point-of-care circulating cathodic antigen test. Schistosoma mansoni-positive children, referred to as first-generation cases (FGCs), were tracked and treated including up to five members of their families. Second-generation cases, identified by the FGCs as their close, non-relative contacts, were also tracked, tested, and treated, including up to five members of their families. The prevalence of schistosomiasis among screened FGCs was 16.5% (33/200) in both villages. Twenty-four FGCs were included in the study. Prevalence among 94 contacts of FGCs was 46.8% (44/94). The proportion was higher in Muda than Bulunga village (61.2% versus 31.1%, χ2 = 10.6611, P = 0.005). Prevalence among SGCs and their contacts was 37.5% (9/24) and 47.1% (49/104), respectively. Overall, the 5T strategy identified 102 additional cases out of 222 tracked from FGCs, 95% of whom were treated, at a total time of 52 hours. Our data demonstrate the potential of the 5T strategy in identifying and treating additional cases in the community and hence its practicality in schistosomiasis control in low-prevalence settings at relatively low time and resources investment.

Current Status of Urinary Schistosomiasis Among Communities in Kurmuk District, Western Ethiopia: Prevalence and Intensity of Infection

Background

Schistosomiasis is a highly prevalent but neglected tropical disease, particularly in sub-Saharan Africa. In Ethiopia, urogenital schistosomiasis due to Schistosoma haematobium has been known to be endemic in several lowland areas. This study was designed to determine the current prevalence and intensity of the urogenital schistosomiasis among communities in Kurmuk District, western Ethiopia.

Methods

Urine filtration technique and urine dipstick test were used to screen for S. haematobium eggs and hematuria, respectively. The data were analyzed with SPSS version 23. Logistic regression and odds ratio were used to measure associations and strength between prevalence, intensity, and independent variables. P-values <.05 at 95% CI were considered statistically significant.

Results

The overall prevalence of S. haematobium infection as determined by urine filtration was 34.2% (138/403). In bivariate analysis, the most infected (45.4%) age groups were 5 to 12 years (odds ratio [OR] = 4.16, 95% CI: 1.36-12.67), followed by 13 to 20 years (OR = 3.23, 95% CI: 1.01-10.35) with higher significant mean egg count (MEC). The mean egg intensity ranged from 2.39 in Ogendu (CI: 1.05-3.72) to 14.1 in Dulshatalo (CI: 4.98-23.12) villages. The main predictor of infection was swimming habits (adjusted odds ratio [AOR] = 2.43 [CI: 1.19-4.94]). The prevalence of hematuria was 39.2% (158/403), the odds being 2.64 times higher among participants who resided in Dulshatalo than those who resided in Kurmuk (AOR 2.64 [95% CI: 1.43-4.87], P = .004).

Conclusion

To reduce the infection and interrupt transmission, the PC in place in the area using PZQ should be strengthened and continued, alongside with provision of sanitary facilities, safe alternative water supplies and health education. The Federal Ministry of Health of Ethiopia should also collaborate with the health authorities of the Sudan government for the control of trans-boundary transmission of the disease as the transmission foci are shared between the 2 countries.

Using ChEMBL to Complement Schistosome Drug Discovery

Schistosomiasis is one of the most important neglected tropical diseases. Until an effective vaccine is registered for use, the cornerstone of schistosomiasis control remains chemotherapy with praziquantel. The sustainability of this strategy is at substantial risk due to the possibility of praziquantel insensitive/resistant schistosomes developing. Considerable time and effort could be saved in the schistosome drug discovery pipeline if available functional genomics, bioinformatics, cheminformatics and phenotypic resources are systematically leveraged. Our approach, described here, outlines how schistosome-specific resources/methodologies, coupled to the open-access drug discovery database ChEMBL, can be cooperatively used to accelerate early-stage, schistosome drug discovery efforts. Our process identified seven compounds (fimepinostat, trichostatin A, NVP-BEP800, luminespib, epoxomicin, CGP60474 and staurosporine) with ex vivo anti-schistosomula potencies in the sub-micromolar range. Three of those compounds (epoxomicin, CGP60474 and staurosporine) also demonstrated potent and fast-acting ex vivo effects on adult schistosomes and completely inhibited egg production. ChEMBL toxicity data were also leveraged to provide further support for progressing CGP60474 (as well as luminespib and TAE684) as a novel anti-schistosomal compound. As very few compounds are currently at the advanced stages of the anti-schistosomal pipeline, our approaches highlight a strategy by which new chemical matter can be identified and quickly progressed through preclinical development.

The role of the host gut microbiome in the pathophysiology of schistosomiasis

The pathophysiology of schistosomiasis is linked to the formation of fibrous granulomas around eggs that become trapped in host tissues, particularly the intestines and liver, during their migration to reach the lumen of the vertebrate gut. While the development of Schistosoma egg-induced granulomas is the result of finely regulated crosstalk between egg-secreted antigens and host immunity, evidence has started to emerge of the likely contribution of an additional player-the host gut microbiota-to pathological processes that culminate with the formation of these tissue lesions. Uncovering the role(s) of schistosome-mediated changes in gut microbiome composition and function in granuloma formation and, more broadly, in the pathophysiology of schistosomiasis, will shed light on the mechanisms underlying this three-way parasite-host-microbiome interplay. Such knowledge may, in turn, pave the way towards the discovery of novel therapeutic targets and control strategies.

Molecular dynamics-derived pharmacophores of Schistosoma glutathione transferase in complex with bromosulfophthalein: Screening and analysis of potential inhibitors

Schistosoma glutathione transferases (GSTs) have been identified as attractive drug targets for the design of novel antischistosomals. Here, we used in silico methods to validate the discriminative inhibitory properties of bromosulfophthalein (BSP) against the 26-kDa GST from S. japonicum (Sj26GST), and the 28-kDa GST from S. haematobium (Sh28GST), versus human GST (hGST) isoforms alpha (hGSTA), mu (hGSTM) and pi (hGSTP). The use of BSP as an archetypal selective inhibitor was harnessed to produce molecular dynamics-derived pharmacophores of the two targets. Pharmacophore-based screening using a large dataset of experimental and approved drug compounds was performed to produce a shortlist of candidates. The top candidate for each target was prioritised via molecular docking, yielding guanosine-3'-monophosphate-5'-diphosphate (G3D) for Sj26GST, and quercetin-3'-O-phosphate (Q3P) for Sh28GST. Comparative molecular dynamics studies of both candidates compared to BSP showed similar characteristics of binding stability and strength, suggesting their potential to emulate the inhibitory effects of BSP.

Understanding key vectors and vector-borne diseases associated with freshwater ecosystem across Africa: Implications for public health

The emerging and re-emerging vector-borne diseases transmitted by key freshwater organisms have remained a global concern. As one of the leading biodiversity hotspots, the African ecoregion is suggested to harbour the highest number of freshwater organisms globally. Among the commonly found organisms in the African ecoregion are mosquitoes and snails, with a majority of their life cycle in freshwater, and these freshwater organisms can transmit diseases or serve as carriers of devastating diseases of public health concerns. However, synthetic studies to link the evident abundant presence and wide distribution of these vectors across the freshwater ecosystems in Africa with the increasing emerging and re-emerging vector-borne diseases in Africa are still limited. Here, we reviewed documented evidence on vector-borne diseases and their transmission pathways in Africa to reduce the knowledge gap on the factors influencing the increasing emerging and re-emerging vector-borne diseases across Africa. We found the population distributions or abundance of these freshwater organisms to be increasing, which is directly associated with the increasing emerging and re-emerging vector-borne diseases across Africa. Furthermore, we found that although the current changing environmental conditions in Africa affect the habitats of these freshwater organisms, current changing environmental conditions may not be suppressing the population distributions or abundance of these freshwater organisms. Instead, we found that these freshwater organisms are extending their geographic ranges across Africa, which may have significant public health implications in Africa. Thus, our study demonstrates the need for future studies to integrate the environmental conditions of vectors' habitats to understand if these environmental conditions directly or indirectly influence the vectorial capacities and transmission abilities of vectors of diseases. We propose that such studies will be necessary to guide policymakers in making informed policies to help control vector-borne diseases.

Pyrethroid insecticides pose greater risk than organophosphate insecticides to biocontrol agents for human schistosomiasis

Use of agrochemicals, including insecticides, is vital to food production and predicted to increase 2-5 fold by 2050. Previous studies have shown a positive association between agriculture and the human infectious disease schistosomiasis, which is problematic as this parasitic disease infects approximately 250 million people worldwide. Certain insecticides might runoff fields and be highly toxic to invertebrates, such as prawns in the genus Macrobrachium, that are biocontrol agents for snails that transmit the parasites causing schistosomiasis. We used a laboratory dose-response experiment and an observational field study to determine the relative toxicities of three pyrethroid (esfenvalerate, λ-cyhalothrin, and permethrin) and three organophosphate (chlorpyrifos, malathion, and terbufos) insecticides to Macrobrachium prawns. In the lab, pyrethroids were consistently several orders of magnitude more toxic than organophosphate insecticides, and more likely to runoff fields at lethal levels according to modeling data. At 31 water contact sites in the lower basin of the Senegal River where schistosomiasis is endemic, we found that Macrobrachium prawn survival was associated with pyrethroid but not organophosphate application rates to nearby crop fields after controlling for abiotic and prawn-level factors. Our laboratory and field results suggest that widely used pyrethroid insecticides can have strong non-target effects on Macrobrachium prawns that are biocontrol agents where 400 million people are at risk of human schistosomiasis. Understanding the ecotoxicology of high-risk insecticides may help improve human health in schistosomiasis-endemic regions undergoing agricultural expansion.

Biochanin A in murine Schistosoma mansoni infection: effects on inflammation, oxidative stress and fibrosis

Biochanin A (BCA) is a multifunctional natural compound that possesses anti-infective, anti-inflammatory, anti-oxidative and hepatoprotective effects. The aim of the study was to assess the therapeutic efficacy of BCA on Schistosoma mansoni-infected mice. Fifty mice were divided into six different groups as non-infected, non-infected BCA-treated, infected untreated, early infected BCA-treated (seven days post-infection (dpi)), late infected BCA-treated 60 dpi and infected praziquantel (PZQ)-treated groups. Parasitological, histopathological examination and immunohistochemical staining of transforming growth factor (TGF)-β, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) were investigated in liver sections. Cytochrome P450 (CYP450) gene expression of S. mansoni was evaluated by quantitative real-time polymerase chain reaction (RT-qPCR). A single dose of BCA significantly reduced worm burden in early (82.14%) and late infection (77.74%), mean tissue egg load in early (7.27 ± 0.495) and late BCA administration (7.63 ± 0.435) and decreased granuloma size. CYP450 mRNA expression was significantly reduced in early BCA treatment as compared to late treatment which emphasizes that early administration of BCA had more pronounced effects on worms than late administration. Both early and late BCA administration led to significant reduction in inflammatory cytokines as TGF and iNOS. Although the reduction of TGF and iNOS in BCA-treated mice was superior to PZQ, no statistically significant differences were noted. However, a significant downregulation of COX2 was noted in hepatocytes as compared to both infected control and PZQ-treated mice. BCA has schistosomicidal, anti-inflammatory, antioxidant and anti-fibrotic effects and could be regarded as a potential drug in schistosomiasis treatment.

Metabolomics for biomarker discovery in schistosomiasis: A systematic scoping review

Background

Metabolomic based approaches are essential tools in the discovery of unique biomarkers for infectious diseases via high-throughput global assessment of metabolites and metabolite pathway dysregulation. This in-turn allows the development of diagnostic tools and provision of therapeutics. In this review, we aimed to give an overview of metabolite biomarkers and metabolic pathway alterations during Schistosoma haematobium and Schistosoma mansoni infections.

Methods

We conducted the review by systematically searching electronic databases and grey literature to identify relevant metabolomics studies on schistosomiasis. Arksey and O’Malley methodology for conducting systematic scoping reviews was applied. A narrative summary of results was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping review guidelines.

Results

Twelve articles included in the review identified 127 metabolites, whose concentrations were considerably altered during S. mansoni and S. haematobium infections. The metabolites were assigned to metabolic pathways involved in energy (34.6%), gut microbial (11.0%), amino acid (25.2%), nucleic acids (6.3%), immune proteins (8.7%) hormones (2.4%) and structural proteins/lipids (11.8%). Energy related metabolic pathways were the most affected during schistosome infections with metabolites such as succinate, citrate, aconitate and fumarate of the tricarbocylic acid cycle being significantly altered in organ, serum and plasma samples. Amino acid metabolism was also impacted during schistosome infections as phenylacetylglycine, alanine, taurine, 2-oxoisocaproate and 2-oxoisovalerate emerged as potent biomarkers. Elevated structural proteins such as actin, collagen and keratin concentrations were identified as biomarkers of liver fibrosis, a common pathological feature in chronic schistosomiasis infections. Hippurate was a major metabolite biomarker in the gut microbial related pathway.

Conclusions

The analysis of the literature revealed that energy related metabolic pathways are considerably altered during S. mansoni and S. haematobium infections. Therefore, their metabolites may provide biomarkers for diagnosis and prognosis in addition to providing therapeutics for parasitic infections. This scoping review has identified a need to replicate more schistosomiasis metabolomic studies in humans to complement animal-model based studies.

Effect of pharmacogenetic variations on praziquantel plasma concentration and safety outcomes among school children in Rwanda

School-based mass drug administration (MDA) of Praziquantel (PZQ) is the global intervention strategy for elimination of schistosomiasis. Genetic variations in drug metabolizing enzymes and transporter proteins influences drug exposure and treatment outcomes, but data on PZQ pharmacokinetics and safety outcomes are scarce. We investigated the effect of pharmacogenetics variations on PZQ plasma concentrations and safety outcomes among 462 Rwandan schoolchildren who received single dose PZQ and albendazole in MDA. Genotyping for common functional variant alleles CYP3A4*1B, CYP3A5 (*3, *6, *7), CYP2C19 (*2, *3, *17), CYP2C9 (*2, *3) and CYP2J2*7 were done. Plasma concentration of PZQ, cis-4-OH-PZQ and trans-4-OH-PZQ were measured using LC/MS/MS. Active safety monitoring was done on days 1, 2, and 7 post-MDA. CYP2C9 and CYP2C19 genotypes were significantly associated with PZQ plasma concentrations and its cis- and trans-4-OH-PZQ/PZQ metabolic ratios (MR). CYP2C9*2 and CYP2C9*3 carriers had significantly higher PZQ concentration (p = 0.02), lower trans-4-OH-PZQ/PZQ (p < 0.001), and cis-4-OH-PZQ/PZQ (p = 0.02) MR. CYP2C19 (*2, *3) carriers had significantly higher plasma PZQ concentration than CYP2C19 *1/*1 and CYP2C19 *17 carriers (*1/*17 or *17/*17) (p < 0.001). CYP3A4 was significantly associated with cis-4-OH-PZQ MR (p = 0.04). Lower cis-4-OH-PZQ/PZQ MR (p < 0.0001) was a predictor of MDA-associated adverse events, but no significant association with genotypes were found. In conclusion, CYP2C9 and CYP2C19 genotypes significantly influence the plasma PZQ concentration and its MR. Lower cis-4-OH-PZQ/PZQ MR is significant predictor of adverse events following MDA.

Epidemiology of pediatric schistosomiasis in hard-to-reach areas and populations: A scoping review protocol

Background: Schistosomiasis is a neglected tropical disease (NTD) that affects millions of people. Children are the most vulnerable group to developing overt disease. An estimated 779 million people are at risk of schistosomiasis and 50 million preschool-age children (PSAC) need treatment. PSAC are not currently targeted by national chemotherapy campaigns due to a lack of suitable pediatric formulations of praziquantel. The Pediatric Praziquantel Consortium has developed an orally dispersible praziquantel formulation (arpraziquantel) and is facilitating its adoption for schistosomiasis control by endemic countries through the ADOPT program - an implementation research program that paves the way for the large-scale delivery of the child-friendly formulation to treat schistosomiasis in preschool-aged children in endemic countries. A key challenge for comprehensive NTD control including schistosomiasis is reaching all at-risk populations, including those hard to reach. Main access barriers include geographic, social and economic conditions. Objective : This scoping literature review aims to document the epidemiology of schistosomiasis in children under 6 years of age living in hard-to-reach areas and populations. Methods : This review will adopt the five-stage scoping review process of identifying the research question, identifying relevant studies, study selection, charting data and collating, summarizing and reporting results. Electronic databases including Medline, Web of Science, Embase (Ovid), LILACS and African Journals OnLine (AJOL) will be searched for relevant articles. Two independent reviewers will screen identified articles using a two-stage approach of reviewing the title/abstract and then the full text of provisionally retained articles. Relevant literatures will be downloaded into EndNote X9 to maintain and manage citation and facilitate the overall review process. A meta-analysis will be conducted if indicated. Relevance : The results will provide insights into the burden of schistosomiasis among marginalized PSAC, aiming to produce evidence on the need for inclusion of this population when designing the expansion of preventive chemotherapy programs.

Understanding perceptions of schistosomiasis and its control among highly endemic lakeshore communities in Mayuge, Uganda

BACKGROUND

Schistosomiasis is a neglected tropical disease and a serious global-health problem with over 230 million people requiring treatment, of which the majority live in Africa. In Uganda, over 4 million people are infected. Extensive parasitological data exist on infection prevalence, intensities and the impact of repeated praziquantel mass drug administration (MDA). However, how perceptions of schistosomiasis shape prevention and treatment practices and their implications for control measures are much less well understood.

METHODS

Rapid ethnographic appraisals were performed for six weeks in each of three Schistosoma mansoni high endemicity communities on the shores of Lake Victoria, Mayuge District, Uganda. Data were collected between September 2017 and April 2018. Data were collected through structured observations, transect walks, and participant observation, and sixty in-depth interviews and 19 focus group discussions with purposively recruited participants. Data were analyzed thematically using iterative categorization, looking at five key areas: perceptions of 1) the symptoms of schistosomiasis; 2) the treatment of schistosomiasis; 3) how schistosomiasis is contracted; 4) how schistosomiasis is transmitted onwards and responsibilities associated with this; and 5) how people can prevent infection and/or onward transmission.

RESULTS

Observations revealed open defecation is a common practice in all communities, low latrine coverage compared to the population, and all communities largely depend on lake water and contact it on a daily basis. Perceptions that a swollen stomach was a sign/symptom of 'ekidada' (caused by witchcraft) resulted in some people rejecting free praziquantel in favour of herbal treatment from traditional healers at a fee. Others rejected praziquantel because of its perceived side effects. People who perceived that schistosomiasis is caught from drinking unboiled lake water did not seek to minimize skin contact with infected water sources. Community members had varied perceptions about how one can catch and transmit schistosomiasis and these perceptions affect prevention and treatment practices. Open defecation and urinating in the lake were considered the main route of transmission, all communities attributed blame for transmission to the fishermen which was acknowledged by some fishermen. And, lastly, schistosomiasis was considered hard to prevent due to lack of access to safe water.

CONCLUSION

Despite over 15 years of MDA and associated education, common misconceptions surrounding schistosomiasis exist. Perceptions people have about schistosomiasis profoundly shape not only prevention but also treatment practices, greatly reducing intervention uptake. Therefore, we advocate for a contextualized health education programme, alongside MDA, implementation of improved access to safe-water and sanitation and continued research.

Urogenital schistosomiasis in three different water access in the Senegal river basin: prevalence and monitoring praziquantel efficacy and re-infection levels

BACKGROUND

Urogenital schistosomiasis is a neglected tropical disease most prevalent in sub-Saharan Africa. In the Senegal river basin, the construction of the Diama dam led to an increase and endemicity of schistosomiasis. Since 2009, praziquantel has frequently been used as preventive chemotherapy in the form of mass administration to Senegalese school-aged children without monitoring of the treatment efficacy and the prevalence after re-infection. This study aims to determine the current prevalence of urogenital schistosomiasis (caused by Schistosoma haematobium), the efficacy of praziquantel, and the re-infection rates in children from five villages with different water access.

METHODS

The baseline prevalence of S. haematobium was determined in August 2020 in 777 children between 5 and 11 years old and a single dose of praziquantel (40 mg/kg) was administered to those positive. The efficacy of praziquantel and the re-infection rates were monitored 4 weeks and 7 months after treatment, respectively, in 226 children with a high intensity of infection at baseline.

RESULTS

At the baseline, prevalence was low among children from the village of Mbane who live close to the Lac de Guiers (38%), moderate among those from the villages of Dioundou and Khodit, which neighbor the Doue river (46%), and very high at Khodit (90.6%) and Guia (91.2%) which mainly use an irrigation canal. After treatment, the observed cure rates confirmed the efficacy of praziquantel. The lowest cure rate (88.5%) was obtained in the village using the irrigation canal, while high cure rates were obtained in those using the lake (96.5%) and the river (98%). However, high egg reduction rates (between 96.7 and 99.7%) were obtained in all the villages. The re-infection was significantly higher in the village using the canal (42.5%) than in the villages accessing the Lac de Guiers (18.3%) and the Doue river (14.8%).

CONCLUSION

Praziquantel has an impact on reducing the prevalence and intensity of urogenital schistosomiasis. However, in the Senegal river basin, S. haematobium remains a real health problem for children living in the villages near the irrigation canals, despite regular treatment, while prevalence is declining from those frequenting the river and the Lac de Guiers. Trial registration ClinicalTrials.gov, NCT04635553. Registered 19 November 2020 retrospectively registered, https://www.

CLINICALTRIALS

gov/ct2/show/NCT04635553?cntry=SN&draw=2&rank=4.

Spatial distribution, abundance, and infection rates of human schistosome-transmitting snails and related physicochemical parameters in KwaZulu-Natal (KZN) province, South Africa

This study investigated the spatial distribution, abundance, and infection rates of human schistosome-transmitting snails and related physicochemical parameters and environmental factors in 11 districts in KwaZulu-Natal (KZN) province, South Africa, from December 2020-February 2021. Snail sampling was carried out in 128 sites by two people for 15 min using scooping and handpicking methods. Geographical information system (GIS) was used to map surveyed sites. In situ measurements of physicochemical parameters were recorded, while remote sensing was used to obtain measurements for climatic factors required to achieve the study's objective. Cercarial shedding and snail-crushing methods were used to detect snail infections. Kruskal-Wallis test was used to test the differences in snail abundance among snail species, districts, and habitat types. A negative binomial generalized linear mixed model was used to identify the physicochemical parameters and environmental factors influencing the abundance of snail species. A total of 734 human schistosome-transmitting snails were collected. Bu. globosus were significantly more abundant (n = 488) and widely distributed (found in 27 sites) compared to B. pfeifferi (n = 246) found in 8 sites. Bu. globosus and B. pfeifferi had infection rates of 3.89% and 2.44%, respectively. Dissolved oxygen and normalized difference vegetation index showed a statistically positive relationship, while normalized difference wetness index showed a statistically negative relationship with the abundance of Bu. globosus. However, there was no statistically significant relationship between B. pfeifferi abundance, physicochemical parameters, and climatic factors. Our study described the current distribution, abundance, and infection status of human schistosome-transmitting snails in KZN province, which will contribute to informing control measure policies for schistosomiasis.

Urogenital schistosomiasis outbreak in a basic school, Volta Region, Ghana: a case-control study

Introduction

schistosomiasis is a neglected parasitic infection caused by nematode worms. It affects approximately 200 million people globally. Prevalence in Ghana is 23.3%, mostly affecting school children. On November 28th 2018, the Disease Surveillance Department received reports of increase in occurrence of bloody urine among students of a basic school in the Volta Region. We investigated to identify the agent and source, to determine the magnitude, risk factors and to implement control measures.

Methods

we conducted a case-control study. A suspected case was any student of the school, who has bloody urine with or without: dysuria, itching of the skin, frequent urination or lower abdominal pain from September 2018 to November 2018. A confirmed case was one with laboratory-isolation of Schistosoma ova in appropriate urine sample. We identified cases from the school and hospital records. We collected socio-demographic, clinical and exposure data from cases and controls. Descriptive and inferential analysis were performed to estimate odds ratios at 95% confidence intervals (CI) to determine associations.

Results

of 880 students, 112 suspected cases were identified (attack rate = 12.7%). Mean age of suspected cases was 14-years (standard deviation = ±3.5). Confirmed cases were 76.8%(86/112). Males had twice odds of becoming cases (cOR = 2.3, 95% CI = 1.35-3.96). Fishing (cOR = 7.29, 95% CI = 4.08-13.04) and swimming (aOR = 44.63, 95% CI = 4.73-420.86) were factors significantly associated with infection. Students with previous history of bloody urine had greater odds of being cases (aOR = 47.9, 95% CI = 4.19-546.55).

Conclusion

Schistosoma haematobium was isolated in this outbreak. Fishing and swimming were risky water-related activities. WASH education and mass drug administration with Praziquantel were control measures.

SARS-COV-2/COVID-19: scenario, epidemiology, adaptive mutations, and environmental factors

The coronavirus pandemic of 2019 has already exerted an enormous impact. For over a year, the worldwide pandemic has ravaged the whole globe, with approximately 250 million verified human infection cases and a mortality rate surpassing 4 million. While the genetic makeup of the related pathogen (SARS-CoV-2) was identified, many unknown facets remain a mystery, comprising the virus's origin and evolutionary trend. There were many rumors that SARS-CoV-2 was human-borne and its evolution was predicted many years ago, but scientific investigation proved them wrong and concluded that bats might be the origin of SARS-CoV-2 and pangolins act as intermediary species to transmit the virus from bats to humans. Airborne droplets were found to be the leading cause of human-to-human transmission of this virus, but later studies showed that contaminated surfaces and other environmental factors are also involved in its transmission. The evolution of different SARS-CoV-2 variants worsens the condition and has become a challenge to overcome this pandemic. The emergence of COVID-19 is still a mystery, and scientists are unable to explain the exact origin of SARS-CoV-2. This review sheds light on the possible origin of SARS-CoV-2, its transmission, and the key factors that worsen the situation.

Assessment of awareness and knowledge of schistosomiasis among school-aged children (6-13 years) in the Okavango Delta, Botswana

BACKGROUND

Schistosomiasis is a global health problem affecting 250 million people, with 90% in Sub-Saharan Africa. In Botswana, the burden is high in the Okavango delta because of the water channels. WHO recommends integrated measures, including access to clean water, sanitation, health education, and drugs to control and eliminate schistosomiasis. Gauging knowledge and awareness of schistosomiasis for School-Aged Children (SAC) is crucial. Our study aimed at assessing knowledge and awareness of schistosomiasis among SAC in the Okavango Delta.

METHODS

A cross-sectional survey assessing awareness and knowledge of schistosomiasis in schools was conducted. 480 questionnaires were administered to gather demographic profiles, awareness, and knowledge of risky behaviors. Chi-square and descriptive analysis determined the differences in SAC`s awareness and knowledge levels based on localities, gender, age, and health education.

RESULTS

The results showed a low awareness level, with only (42%) of respondents having heard about the disease and (52%) knowing its local name. Younger children from Sekondomboro (83%) and Samochima lacked awareness, while children from Mohembo (77%) and those who had health education (70%) demonstrated significant awareness levels (P ≤ 0.001). Seventy-two percent (72%) lacked knowledge of the cause and (95%) did not know the disease life-cycle. Children from Xakao (91%), (85%) Sepopa, and (75%) of younger children did not know haematuria is a symptom of the disease. Older and SAC with health education were more likely to know that swimming is a risk factor (P ≤ 0.001) and (P ≤ 0.05) respectively.

CONCLUSIONS

Although respondents from four schools demonstrated some level of awareness of the disease, and knowledge of risky behaviors, the study showed a lack of in-depth knowledge on the life-cycle and cause of the diseases. We, therefore, recommend the implementation of an integrated approach to health education and improvement in access to clean water and sanitation in all study areas.

Hematological and Biochemical changes in Schistosoma mansoni infected patients at Haik Primary Hospital, North-East Ethiopia: A comparative cross-sectional study

Background

Schistosomes are blood dwelling parasites that affect more than 260 million people globally, and over 800 million people are at risk of infection in 74 countries. It causes acute and chronic debilitating diseases. The parasite is reported to alter the hematological and biochemical parameters in humans. Therefore, this study was aimed to evaluate the hematological and biochemical changes in S. mansoni infected adult patients compared to apparently healthy controls.

Methods

A comparative cross-sectional study was conducted at Haik Primary Hospital from February to April 2021. One hundred and eighty study participants consisting of 90 S. mansoni infected patients and 90 apparently healthy controls were recruited using systematic random sampling method. Socio-demographic characteristics and other variables were collected using questionnaires. Stool sample was examined microscopically to detect S. mansoni infection using direct wet mount and Kato Katz technique. In apparently healthy controls, S. mansoni infection was rule out using direct wet mount and Kato Katz technique. Moreover, the intensity of S. mansoni infection was assessed using Kato Katz technique. Blood sample was collected from each study participant to determine the hematological and biochemical profiles. Data were entered in to Epi Data version 3.1 and analyzed using SPSS version 26.0 software. Kolmogorov-Smirnov and Shapiro Wilk normality tests were done to assess the distribution of continuous variables. The Mann-Whitney U test and Kruskal Wallis H test was done to compare the differences among nonnormally distributed variables between S. mansoni infected patients and healthy controls. P-values <0.05 at 95%CI were considered as statistically significant.

Result

The mean age (SD) of S. mansoni infected patients and apparently healthy controls was 30.33 (±12.26) and 31.2 (±12.85) years old, respectively. The prevalence of anemia, and thrombocytopenia among S. mansoni infected patients were 23.3% and 26.7%, respectively. Erythrocytic sedimentation rate (ESR) was significantly elevated among S. mansoni infected patients than apparently healthy controls. The median white blood cell count, red blood cell count, red blood cell indices, and platelet indices were significantly lower among S. mansoni infected patients compared to apparently healthy controls (P<0.05). On the other hand, the median eosinophil count was significantly elevated among S. mansoni infected patients compared to apparently healthy controls (P<0.05). This study also showed significantly elevated values of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and direct bilirubin and lower albumin, total cholesterol and triglycerides among S. mansoni infected patients compared to apparently healthy controls. Kruskal Wallis H test showed a significant difference in the median of most hematological and biochemical parameters between moderate and heavy intensity of infection with light intensity of infection and apparently healthy controls.

Conclusion

The findings of this study showed significantly altered hematological values and liver function tests among S. mansoni infected patients compared to apparently healthy controls. Therefore, screening of S. mansoni infected patients for various hematological and biochemical parameters and providing treatment to the underlying abnormalities is very crucial to avoid schistosomiasis associated morbidity and mortality.

A novel theatre-based behaviour change approach for influencing community uptake of schistosomiasis control measures

Background

Appropriate behaviour change with regard to safe water contact practices will facilitate the elimination of schistosomiasis as a public health concern. Various approaches to effecting this change have been trialled in the field but with limited sustainable outcomes. Our case study assessed the effectiveness of a novel theatre-based behaviour change technique (BCT), in combination with cohort awareness raising and capacity training intervention workshops.

Methodology

Our study was carried out in four rural communities in the Mwanza region of Tanzania and in the semi-urban town of Kemise, Ethiopia. We adapted the Risk, Attitude, Norms, Ability and Self-regulation (RANAS) framework and four phases using a mixed methods approach. Participatory project phase engagement and qualitative formative data were used to guide the design of an acceptable, holistic intervention. Initial baseline (BL) data were collected using quantitative questionnaire surveys with 804 participants in Tanzania and 617 in Ethiopia, followed by the theatre-based BCT and capacity training intervention workshops. A post-intervention (PI) survey was carried out after 6 months, with a participant return rate of 65% in Tanzania and 60% in Ethiopia.

Results

The intervention achieved a significant improvement in the knowledge of schistosomiasis transmission being associated with poorly managed sanitation and risky water contact. Participants in Tanzania increased their uptake of preventive chemotherapy (males: BL, 56%; PI, 73%, females: BL, 43%; PI, 50%). There was a significant increase in the selection of sanitation (Tanzania: BL, 13%; PI, 21%, Ethiopia: BL, 63%; PI, 90%), safe water and avoiding/minimising contact with infested waters as prevention methods in Tanzania and Ethiopia. Some of the participants in Tanzania followed on from the study by building their own latrines.

Conclusions

This study showed that substantial positive behaviour changes in schistosomiasis control can be achieved using theatre-based BCT intervention and disease awareness training. With the appropriate sensitisation, education and stakeholder engagement approaches, community members were more open to minimising risk-associated contact with contaminated water sources and were mobilised to implement preventive measures.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05421-5.

Intestinal helminthiasis survey with emphasis on schistosomiasis in Koga irrigation scheme environs, northwest Ethiopia

Background

Distribution of schistosomiasis is more focal due to spatial heterogeneities in intermediate host snail dynamics and water contact behavior of humans. This makes the search for new transmission foci of schistosomiasis and its connection with malacologically receptive water bodies essential for effective control of its transmission. This study was intended to assess the prevalence of intestinal helminth infections among schoolchildren and Schistosoma mansoni transmission in Koga irrigation scheme surroundings, northwest Ethiopia.

Materials and methods

Cross-sectional parasitological and malacological surveys were conducted in three schools and nearby water bodies, respectively around Koga irrigation scheme. Stool specimens were collected from 421 randomly selected schoolchildren and microscopically examined using Kato-Katz and formol-ether concentration methods. Malacological surveys were carried out and the identified Biomphalaria pfeifferi snails were screened for schistosome infection. Swiss albino mice were exposed to schistosome cercariae shed by Biomphalaria pfeifferi for definite identification of Schistosoma species.

Results

Among the examined schoolchildren, 22.6% (95% CI: 18.7%-26.9%) were positive for at least one intestinal helminths species. Ascaris lumbricoides was the most frequent intestinal helminth detected among forty (9.5%) children. Schistosoma mansoni was detected among 4.8% (95% CI: 2.9%-7.2%) of children and its prevalence was significantly higher among male children (p = 0.038) and those attending in Mengesha Jemberie Primary School (p = 0.044). Biomphalaria pfeifferi snails were identified in water bodies in close proximity to Mengesha Jemberie and Wotete Abay Primay schools. Schistosoma mansoni adult worms were harvested after exposure of mice to cercariae shed from Biomphalaria pfeifferi snails collected from water bodies nearby Mengesha Jemberie Primary School.

Conclusions

Schistosoma mansoni infection of schoolchildren, findings of schistosome infected snails and establishment of mice infection confirm that transmission is taking place in the study areas. Hence, snail control and other measures such as provision of sanitary facilities and health education are recommended.

A Comparative Cross-Sectional Study of Coagulation Profiles and Platelet Parameters of Schistosoma mansoni-Infected Adults at Haik Primary Hospital, Northeast Ethiopia

Introduction. Schistosoma mansoni is an intravascular parasite that interacts with all components of the host blood. Nearly, 10% of S. mansoni-infected patients progress to severe hepatosplenic Schistosomiasis is characterized by periportal fibrosis, obstruction of intrahepatic veins, presinusoidal portal hypertension, and splenomegaly. Thus, this study aimed to compare the basic coagulation profiles and platelet parameters of S. mansoni-infected adults and noninfected individuals as controls at Haik Primary Hospital, Northeast Ethiopia. Methods. A comparative cross-sectional study was conducted at Haik Primary Hospital from April to June 2021. The diagnosis and intensity of S. mansoni infection was determined using the Kato–Katz technique. The coagulation profiles and platelet parameters were analyzed using coagulation and hematology analyzers. Data were analyzed using SPSS version 26.0. The Kolmogorov–Smirnov and Shapiro–Wilk tests were done to check the distribution of continuous variables. The Mann–Whitney U test was used to compare the coagulation profiles and platelet parameters. Spearman’s rank-order correlation was done to assess the correlation between the intensity of infection and coagulation profiles and platelet parameters. In all comparison, a $P$ value <0.05 was considered statistically significant. Result. In this study, a total of 180 study participants (90 S. mansoni-infected adults and 90 controls) were included. Of the total S. mansoni-infected adults, 55.6%, 28.9%, 33, and 15.6% had light, moderate, and heavy intensity of infections, respectively. All S. mansoni-infected study participants had prolonged prothrombin time (PT) and international normalized ratio (INR). Moreover, about 80% of S. mansoni-infected adults had prolonged activated partial thromboplastin time (APTT). Thrombocytopenia was found in 26.7% of the S. mansoni-infected adults. The Mann–Whitney U test showed a statistically significant difference in coagulation profiles between S. mansoni-infected adults and healthy controls ( $P$ -value ≤0.001). The Kruskal–Wallis H-test showed a significant difference in PT, APTT, and INR between the intensity of infection and healthy controls ( $P$ -value <0.05). Conclusion. This study showed a prolonged coagulation time in S. mansoni-infected individuals. Thus, screening of schistosomiasis patients for hemostatic abnormalities and treating the underlying disorder is crucial.

Efficacy of Praziquantel Treatment and Schistosoma Mansoni Infection among Primary School Children in Kemisse Town, Northeast Ethiopia

Background

Schistosoma mansoni infection is endemic in Ethiopia. The epidemiology of S. mansoni and the efficacy of praziquantel among schoolchildren have not been well documented in different parts of the country including our study area. Therefore, this study aimed to determine the status of S. mansoni infection and evaluate the therapeutic efficacy of praziquantel among school children in northeast Ethiopia.

Methods

A comparative cross-sectional study was conducted among 499 children of two preschool children. Stool specimens were collected and microscopically examined using Kato-Katz (41.7 gram) methods. Positive children were treated with a single oral dose of praziquantel at 40 mg/kg body weight. Egg reduction and cure rates were assessed 4 weeks post-treatment to evaluate the therapeutic efficacy of praziquantel against S. mansoni infection.

Results

The overall prevalence of S. mansoni infection among the schoolchildren was 52.1% with a mean intensity of 546 eggs per gram of stool. Majorities of the S. mansoni infections were moderate to heavy intensity, with only 5.0% light infections. Praziquantel administered at a single oral dose of 40 mg/kg achieved a cure rate of 91.7% and reduced the egg rate by 86.8%. Twenty-one schoolchildren remained infected at 4 weeks post-treatment, among which 6 and 15 children had moderate and light infections, respectively.

Conclusions

S. mansoni prevalence among primary school children in Northeast Ethiopia was high, highlighting the need to implement school-based chemotherapy with annual frequency. The efficacy of praziquantel at 40 mg/kg is sufficient to permit continued use in treating S. mansoni-infected schoolchildren.

Real-time and automated monitoring of antischistosomal drug activity profiles for screening of compound libraries

Schistosomiasis is a neglected tropical disease that affects over 200 million people annually. As the antischistosomal drug pipeline is currently empty, repurposing of compound libraries has become a source for accelerating drug development, which demands the implementation of high-throughput and efficient screening strategies. Here, we present a parallelized impedance-based platform for continuous and automated viability evaluation of Schistosoma mansoni schistosomula in 128 microwells during 72 h to identify antischistosomal hits in vitro. By initially screening 57 repurposed compounds against larvae, five drugs are identified, which reduce parasite viability by more than 70%. The activity profiles of the selected drugs are then investigated via real-time dose-response monitoring, and four compounds reveal high potency and rapid action, which renders them suitable candidates for follow-up tests against adult parasites. The study shows that our device is a reliable tool for real-time drug screening analysis of libraries to identify new promising therapeutics against schistosomiasis.

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Scalable, plastic microwell chip with integrated platinum electrodes

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Automated impedance-based recording of 128 microwell units in parallel

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Continuous monitoring of in vitro drug library efficacy on schistosomula for 72 h

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Identification of four fast-acting antischistosomal drugs for in vivo testing

Rationale and design of a screening study to detect schistosomiasis-associated pulmonary hypertension in Ethiopia and Zambia

Schistosomiasis is a major cause of pulmonary arterial hypertension (PAH) worldwide, but the prevalence and risk factors for schistosomiasis-associated PAH (SchPAH) development are not well understood. Schistosomiasis-associated hepatosplenic disease (SchHSD) is thought to be a major risk factor for PAH development. Herein, we describe our plans for prospectively screening SchHSD subjects for clinical evidence of PAH at two major academic medical centers and national referral hospitals in Addis Ababa, Ethiopia and Lusaka, Zambia. The screening study will primarily be conducted by echocardiography, in addition to clinical assessments. Plasma samples will be drawn and banked for subsequent analysis based on preclinical animal model rationale. If successful, this study will demonstrate feasibility of conducting prospective cohort studies of SchPAH screening in schistosomiasis-endemic regions of Africa, and provide initial data on clinic-based disease prevalence and potential mechanistic biomarkers underlying disease pathogenesis.