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

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

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

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

Evaluation of a modified quantitative polymerase chain reaction assay for genus Schistosoma detection using stool and urine samples from schistosomiasis endemic areas in Kenya.

INTRODUCTION: The microscopy-based Kato-Katz and urine filtration techniques have traditionally faced challenges in the detection of schistosomiasis in areas with low infection levels. A modified singleplex Schistosoma genus-specific quantitative real-time polymerase chain reaction (qPCR) assay was therefore evaluated as a sensitive and confirmatory schistosomiasis diagnostic test. METHODOLOGY: The qPCR assay utilized primers and probe targeting internal transcribed spacer- 2 (ITS2) sequence of S. mansoni, S. haematobium and S. intercalatum. A plasmid (pDMD801, 100pg/ul) was used as an internal amplification control and its qPCR assays were run in parallel to the Schistosoma assays. This assay utilized samples collected from 774 participants and microscopically examined for three consecutive days. A total of 699 day-one samples (urine and stools) from two schistosomiasis endemic sites were analyzed. Similarly, 75 persons from a non-endemic control site provided both urine and stool samples that were also analyzed. RESULTS: Using microscopy, the proportion of positives in the two endemic regions altogether was 289/699 (41.3%). Using qPCR, 50.4% of the samples (352/699) were found to be positive for schistosome infection. The percentage of positive samples was slightly higher at 57.8% (203/351) in the S. mansoni endemic site compared with the S. haematobium site at 42.8% (149/348). Majority of the microscopy results were light infections at 26.8% (n = 94) and 26.1% (n = 91) while qPCR majority of the infections were high at 41.6% (n = 146) and 31.3% (n = 109) for the S. mansoni and S. haematobium sites, respectively. There were no positives detected by either microscopy or qPCR in the non-endemic site. Using Bayesian Latent Class Model, which does not use any technique as a gold standard, qPCR showed higher sensitivity (86.4% (PCI: 82.1-90.3)) compared to microscopy (75.6% (PCI: 71.1-80.0)). CONCLUSIONS: This study documents a single day-one sample modified Schistosoma qPCR assay as a powerful improved molecular assay for the detection of schistosomiasis infection that utilize either stool or urine samples. The assay is therefore recommended for monitoring in areas with low infection levels to enable accurate determination of the disease's control endpoint.

Combining network pharmacology, machine learning, molecular docking and molecular dynamic to explore the mechanism of Chufeng Qingpi decoction in treating schistosomiasis.

Background: Although the Chufeng Qingpi Decoction (CQD) has demonstrated clinical effectiveness in the treatment of schistosomiasis, the precise active components and the underlying mechanisms of its therapeutic action remain elusive. To achieve a profound comprehension, we incorporate network pharmacology, bioinformatics analysis, molecular docking, and molecular dynamics simulations as investigative methodologies within our research framework. Method: Utilizing TCMSP and UniProt, we identified formula components and targets. Cytoscape 3.10.0 was used to construct an herb-target interaction network. Genecards, DisGeNET, and OMIM databases were examined for disease-related objectives. A Venn diagram identified the intersection of compound and disease targets. Using Draw Venn, overlapping targets populated STRING for PPI network. CytoNCA identified schistosomiasis treatment targets. GO & KEGG enrichment analysis followed High-scoring genes in PPI were analyzed by LASSO, RF, SVM-RFE. Molecular docking & simulations investigated target-compound interactions. Result: The component's target network encompassed 379 nodes, 1629 edges, highlighting compounds such as wogonin, kaempferol, luteolin, and quercetin. Amongst the proteins within the PPI network, PTGS2, TNF, TGFB1, BCL2, TP53, IL10, JUN, MMP2, IL1B, and MYC stood out as the most prevalent entities. GO and KEGG revealed that mainly involved the responses to UV, positive regulation of cell migration and motility. The signal pathways encompassed Pathways in cancer, Lipid and atherosclerosis, Fluid shear stress and atherosclerosis, as well as the AGE-RAGE. Bioinformatics analysis indicated TP53 was the core gene. Ultimately, the molecular docking revealed that wogonin, kaempferol, luteolin, and quercetin each exhibited significant affinity in their respective interactions with TP53. Notably, kaempferol exhibited the lowest binding energy, indicating a highly stable interaction with TP53. Lastly, we validated the stability of the binding interaction between the four small molecules and the TP53 through molecular dynamics simulations. The molecular dynamics simulation further validated the strongest binding between TP53 and kaempferol. In essence, our research groundbreaking in its nature elucidates for the first time the underlying molecular mechanism of CQD in the therapeutic management of schistosomiasis, thereby providing valuable insights and guidance for the treatment of this disease. Conclusion: This study uncovered the efficacious components and underlying molecular mechanisms of the Chufeng Qingpi Decoction in the management of schistosomiasis, thereby offering valuable insights for future fundamental research endeavors.

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

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

Prevalence of human schistosomiasis in various regions of Tanzania Mainland and Zanzibar: A systematic review and meta-analysis of studies conducted for the past ten years (2013-2023).

Schistosomiasis is a significant public health problem in Tanzania, particularly for the people living in the marginalized settings. We have conducted a systematic review with meta-analysis on the prevalence of schistosomiasis to add knowledge towards the development of effective approaches to control the disease in Tanzania. Online databases namely, Pub Med, SCOPUS and AJOL, were systematically searched and a random effect model was used to calculate the pooled prevalence of the disease. Heterogeneity and the between studies variances were determined using Cochran (Q) and Higgins (I2) tests, respectively. A total of 55 articles met the inclusion criterion for this review and all have satisfactory quality scores. The pooled prevalence of the disease in Tanzania was 26.40%. Tanzania mainland had the highest schistosomiasis prevalence (28.89%) than Zanzibar (8.95%). Sub-group analyses based on the year of publication revealed the going up of the pooled prevalence, whereby for (2013-2018) and (2018-2023) the prevalence was 23.41% and 30.06%, respectively. The prevalence of the Schistosoma mansoni and Schistosoma hematobium were 37.91% and 8.86% respectively. Mara, Simuyu, and Mwanza were the most prevalent regions, with a pooled prevalence of 77.39%, 72.26%, and 51.19%, respectively. The pooled prevalence based on the diagnostic method was 64.11% for PCR and 56.46% for POC-CCA, which is relatively high compared to other tests. Cochrans and Higgins (I2) test has shown significant heterogeneity (p-value = 0.001 and I2 = 99.6). Factors including age, region, diagnostic method and sample size have shown significant contribution to the displayed heterogeneity. The pronounced and increasing prevalence of the disease suggests potential low coverage and possibly lack of involvement of some regions in the control of the disease. This, therefore, calls for an intensive implementation of control interventions in all endemic regions, preferably using an integrated approach that targets several stages of the disease lifecycle.

Computer-aided discovery of novel SmDHODH inhibitors for schistosomiasis therapy: Ligand-based drug design, molecular docking, molecular dynamic simulations, drug-likeness, and ADMET studies.

Schistosomiasis, also known as bilharzia or snail fever, is a tropical parasitic disease resulting from flatworms of the Schistosoma genus. This often overlooked disease has significant impacts in affected regions, causing enduring morbidity, hindering child development, reducing productivity, and creating economic burdens. Praziquantel (PZQ) is currently the only treatment option for schistosomiasis. Given the potential rise of drug resistance and the limited treatment choices available, there is a need to develop more effective inhibitors for this neglected tropical disease (NTD). In view of this, quantitative structure-activity relationship studies (QSAR), molecular docking, molecular dynamics simulations, drug-likeness, and ADMET predictions were applied to 31 inhibitors of Schistosoma mansoni Dihydroorotate dehydrogenase (SmDHODH). The designed QSAR model demonstrated robust statistical parameters including an R2 of 0.911, R2adj of 0.890, Q2cv of 0.686, R2pred of 0.807, and cR2p of 0.825, confirming its robustness. Compound 26, identified as the most active derivative, emerged as a lead candidate for new potential inhibitors through ligand-based drug design. Subsequently, 12 novel compounds (26A-26L) were designed with enhanced inhibition activity and binding affinity. Molecular docking studies revealed strong and stable interactions, including hydrogen bonding and hydrophobic interactions, between the designed compounds and the target receptor. Molecular dynamics simulations over 100 nanoseconds and MM-PBSA free binding energy (ΔGbind) calculations validated the stability of the two best-designed molecules (26A and 26L). Furthermore, drug-likeness and ADMET prediction analyses affirmed the potential of these designed compounds, suggesting their promise as innovative agents for treating schistosomiasis.

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

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

Deep humoral profiling coupled to interpretable machine learning unveils diagnostic markers and pathophysiology of schistosomiasis.

Schistosomiasis, a highly prevalent parasitic disease, affects more than 200 million people worldwide. Current diagnostics based on parasite egg detection in stool detect infection only at a late stage, and current antibody-based tests cannot distinguish past from current infection. Here, we developed and used a multiplexed antibody profiling platform to obtain a comprehensive repertoire of antihelminth humoral profiles including isotype, subclass, Fc receptor (FcR) binding, and glycosylation profiles of antigen-specific antibodies. Using Essential Regression (ER) and SLIDE, interpretable machine learning methods, we identified latent factors (context-specific groups) that move beyond biomarkers and provide insights into the pathophysiology of different stages of schistosome infection. By comparing profiles of infected and healthy individuals, we identified modules with unique humoral signatures of active disease, including hallmark signatures of parasitic infection such as elevated immunoglobulin G4 (IgG4). However, we also captured previously uncharacterized humoral responses including elevated FcR binding and specific antibody glycoforms in patients with active infection, helping distinguish them from those without active infection but with equivalent antibody titers. This signature was validated in an independent cohort. Our approach also uncovered two distinct endotypes, nonpatent infection and prior infection, in those who were not actively infected. Higher amounts of IgG1 and FcR1/FcR3A binding were also found to be likely protective of the transition from nonpatent to active infection. Overall, we unveiled markers for antibody-based diagnostics and latent factors underlying the pathogenesis of schistosome infection. Our results suggest that selective antigen targeting could be useful in early detection, thus controlling infection severity.

Combined interventions for the testing and treatment of HIV and schistosomiasis among fishermen in Malawi: a three-arm, cluster-randomised trial.

BACKGROUND: Undiagnosed HIV and schistosomiasis are highly prevalent among fishermen in the African Great Lakes region. We aimed to evaluate the efficacy of lakeside interventions integrating services for HIV and male genital schistosomiasis on the prevalence of schistosomiasis, uptake of antiretroviral therapy (ART) for HIV, and voluntary male medical circumcision (VMMC) among fishermen in Malawi. METHODS: We conducted a three-arm, cluster-randomised trial in 45 lakeshore fishing communities (clusters) in Mangochi, Malawi. Clusters were defined geographically by their home community as the place where fishermen leave their boats (ie, a landing site). Eligible participants were male fishermen (aged ≥18 years) who resided in a cluster. Clusters were randomly allocated (1:1:1) through computer-generated random numbers to either enhanced standard of care (SOC), which offered invitation with information leaflets to a beach clinic offering HIV testing and referral, and presumptive treatment for schistosomiasis with praziquantel; peer education (PE), in which a nominated fisherman was responsible for explaining the study leaflet to promote services to his boat crew; or peer distribution education (PDE), in which the peer educator explained the leaflet and distributed HIV self-test kits to his boat crew. The beach clinic team and fishermen were not masked to intervention allocation; however, investigators were masked until the final analysis. Coprimary composite outcomes were the proportion of participants who had at least one Schistosoma haematobium egg observed on light microscopy from 10 mL of urine filtrate and the proportion who had self-reported initiating ART or scheduling VMMC by day 28. Outcomes were analysed by intention to treat; multiple imputation for missing outcomes was done; random-effect binomial models adjusting for baseline imbalance and clustering were used to compute unadjusted and adjusted risk differences, risk ratios (RRs) and 95% CIs, and intracluster correlation coefficients for each outcome. This trial is registered with ISRCTN, ISRCTN14354324. FINDINGS: Between March 1, 2022, and Jan 29, 2023, 45 (65·2%) of 69 clusters assessed for eligibility were enrolled in the trial, with 15 clusters per arm. Of the 6036 fishermen screened at baseline, 5207 (86·3%) were eligible for participation: 1745 (87·6%) of 1991 in the enhanced SOC group, 1687 (81·9%) of 2061 in the PE group, and 1775 (89·5%) of 1984 in the PDE group. Compared with the prevalence of active schistosomiasis in the enhanced SOC group (292 [16·7%] of 1745), 241 (13·6%) of 1775 fishermen in the PDE group (adjusted RR 0·80 [95% CI 0·69-0·94]; p=0·0054) and 263 (15·6%) of 1687 fishermen in the PE group (0·92 [0·79-1·07]; p=0·28) had schistosomiasis at day 28. 230 (13·2%) in the enhanced SOC group, 281 (16·7%) in the PE group, and 215 (12·1%) in the PDE group initiated ART or were scheduled for VMMC. ART initiation or VMMC scheduling was not significantly increased with the PDE intervention (0·88 [0·74-1·05); p=0·15) and was marginally increased with the PE intervention (1·16 [0·99-1·37]; p=0·069) when compared with the enhanced SOC group. No serious adverse events were reported in this trial. INTERPRETATION: We found weak evidence for the use of peer education to increase uptake of ART and VMMC, but strong evidence for the added distribution of HIV self-test kits to promote high engagement with services and reduce the prevalence of active schistosomiasis, suggesting a high potential for scale-up in hard-to-reach communities across Malawi. FUNDING: Wellcome Trust and the UK National Institute for Health Research.

Prediction on the spatial distribution of the seropositive rate of schistosomiasis in Hunan Province, China: a machine learning model integrated with the Kriging method.

Schistosomiasis remains a formidable challenge to global public health. This study aims to predict the spatial distribution of schistosomiasis seropositive rates in Hunan Province, pinpointing high-risk transmission areas and advocating for tailored control measures in low-endemic regions. Six machine learning models and their corresponding hybrid machine learning-Kriging models were employed to predict the seropositive rate. The optimal model was selected through internal and external validations to simulate the spatial distribution of seropositive rates. Our results showed that the hybrid machine learning-Kriging model demonstrated superior predictive performance compared to basic machine learning model and the Cubist-Kriging model emerged as the most optimal model for this study. The predictive map revealed elevated seropositive rates around Dongting Lake and its waterways with significant clustering, notably in the central and northern regions of Yiyang City and the northeastern areas of Changde City. The model identified gross domestic product, annual average wind speed and the nearest distance from the river as the top three predictors of seropositive rates, with annual average daytime surface temperature contributing the least. In conclusion, our research has revealed that integrating the Kriging method significantly enhances the predictive performance of machine learning models. We developed a Cubist-Kriging model with high predictive performance to forecast the spatial distribution of schistosomiasis seropositive rates. These findings provide valuable guidance for the precise prevention and control of schistosomiasis.

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

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

Harnessing artificial intelligence microscopy to improve diagnostics for soil-transmitted helminthiasis and schistosomiasis: a review of recent advances and future pathways.

PURPOSE OF REVIEW: This opinion piece aims to explore the transformative potential of integrating artificial intelligence with digital microscopy to enhance diagnostics for soil-transmitted helminthiasis (STH) and schistosomiasis (SCH), two pervasive neglected tropical diseases (NTDs). By aligning innovative artificial intelligence-driven solutions with WHO's strategic objectives and calls for better, more accessible, and more integrated diagnostics, we highlight the latest advancements that may support improved health outcomes in affected communities. RECENT FINDINGS: The review covers recent advancements in artificial intelligence-based diagnostic technologies, emphasizing automated egg detection and quantification. These technologies promise to mitigate challenges such as human error and the need for skilled technicians. SUMMARY: The findings have significant implications for public health, ethical considerations and regulatory pathways, particularly in resource-limited settings. The authors advocate for interdisciplinary collaboration and a strategic focus on meeting WHO target product profiles to ensure uptake, ultimately to support reaching WHO NTD targets.

Interactive and lag effects of environmental factors on the density of schistosome-transmitting Oncomelania hupensis: A twelve-year monthly repeated survey.

Schistosomiasis is a significant public health threat, and Oncomelania hupensis is the only intermediate host for schistosoma japonicum. We conducted 12-year monthly repeated surveys to explore the interactive and lag effects of environmental factors on snail density and to monitor their long-term and seasonal trends in a bottomland around the Dongting Lake region in China. Relevant environmental data were obtained from multiple sources. A Bayesian kernel machine regression model and a Bayesian temporal model combined with a distributed lag model were constructed to analyze interactive and lag effects of environmental factors on snail density. The results indicated the average annual snail density in the study site exhibited an increasing and then decreasing trend, peaking in 2013. Snail densities were the highest in October and the lowest in January in a year. Normalized Difference Vegetation Index (NDVI) and water level were the most effective predictors of snail density, with potential interactions among temperature, precipitation, and NDVI. The mean minimum temperature in January, water level, precipitation and NDVI were positively correlated with snail density at lags ranging from 1 to 4 months. These findings could serve as references for relevant authorities to monitor the changing trend of snail density and implement control measures, thereby reducing the occurrence of schistosomiasis.

Burden of schistosomiasis in global, regional, and national 1990-2019: A systematic analysis for the Global Burden of Disease Study 2019.

BACKGROUND: Despite the gradual decline of schistosomiasis due to the efforts of the WHO and various countries, with the WHO setting a goal to eliminate schistosomiasis by 2030, a comprehensive global assessment of the current status of schistosomiasis has not been conducted. OBJECTIVES: To provide a detailed description of the changes in schistosomiasis from 1990 to 2019 by using the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 database. METHODS: We obtained all relevant data on schistosomiasis worldwide from the Global Burden of Diseases (GBD) database from 1990 to 2019. The mortality, prevalence, disability-adjusted life-years (DALYs), Years of Life Lost (YLLs), Years Lived with Disability (YLDs) of schistosomiasis were examined by Socio-demographic Index (SDI), age, sex, and year at the global, region and national level. RESULTS: From 1990 to 2019, the age-standardized rate(ASR)-prevalence of schistosomiasis has decreased from 2600.9 per 100,000(95% uncertainty interval (UI) 2191.2 to 3059.3) to 1805.0 per 100,000(95% UI 1503.4 to 2146.9). The estimated annual percentage change (EAPC) from 1990 to 2019 was 1.28 (95% UI 1.22 to 1.33) in high SDI regions and -2.45 (95% UI -3.03 to -1.86) in low SDI regions. In North Africa and the Middle East, the most substantial reduction in DALYs occurred, with an observed EAPC of -5.36. CONCLUSION: The burden of schistosomiasis has decreased over the past three decades worldwide. However, the high SDI regions have shown the increasing burden of schistosomiasis. Besides, Multiple countries in Africa still bear a significant burden of schistosomiasis, necessitating robust prevention and control efforts.

Morbidity burden of imported chronic schistosomiasis among West African migrants.

BACKGROUND: Past exposure to schistosomiasis is frequent among migrants from endemic countries, and chronic untreated infection may lead to long-term morbidities. METHODS: We carried out a prospective population-based cross-sectional study among migrants from endemic Sub-Saharan countries living in Barcelona, Spain. Participants had not been previously diagnosed or treated for schistosomiasis. Clinical signs and symptoms were scrutinised through a systematic revision of electronic medical records and an on-site standardised questionnaire, and blood and urine samples were screened for Schistosoma. FINDINGS: We recruited 522 eligible participants, 74.3% males, mean age 42.7 years (SD=11.5, range 18-76), Overall, 46.4% were from Senegal and 23.6% from Gambia. They had lived in the European Union for a median of 16 years (IQR 10-21). The prevalence of a Schistosoma-positive serology was 35.8%. S. haematobium eggs were observed in urine samples in 6 (1.2%) participants. The most prevalent symptoms among Schistosoma-positive participants were chronic abdominal pain (68.8%, OR=1.79; 95%CI 1.2-2.6), eosinophilia (44.9%, OR=2.69; 95%CI 1.8-4.0) and specific symptoms associated with urinary schistosomiasis, like self-reported episodes of haematuria (37.2%; OR=2.47; 95%CI 1.6-3.8), dysuria (47.9%, OR=1.84; 95%CI=1.3-2.7) and current renal insufficiency (13.4%; OR=2.35; 95%CI=1.3-4.3). We found a significant prevalence of gender-specific genital signs and symptoms among females (mainly menstrual disorders) and males (erectile dysfunction and pelvic pain). Individuals typically presented with a multitude of interconnected symptoms, most commonly chronic abdominal pain, which are often disregarded. CONCLUSIONS: Despite the lack of urine parasite identification, the high incidence of clinical signs and symptoms strongly correlated with a positive schistosomiasis serology suggests the existence of a heavy clinical burden among long-term West African migrants living for years/decades in the study region. More research is urgently required to determine whether these symptoms are the result of long-term sequelae or a persistent active Schistosoma infection.

Schistosomiasis in migrant children and adolescents in a paediatric tropical referral unit in Spain: diagnosis and long-term management challenges.

Globalisation and population movement have led to an increasing number of migrant children residing in areas non-endemic for schistosomiasis. However, diagnosing and managing schistosomiasis in children remain controversial. This study aims to investigate the prevalence of schistosomiasis in migrant children and to describe the diagnostic approach and management strategies, including long-term follow-up, to explore the potential role of serological tests in evaluating treatment response. We conducted a retrospective descriptive study spanning from January 2014-July 2021 at a referral unit for Paediatric Tropical Diseases in Madrid (Spain). The study included patients under 18 years diagnosed with schistosomiasis. Of 679 children screened for schistosomiasis, 73 (10.8%) tested positive. The median age was 16.3 years [IQR 9-17.6], 74% male. The majority originated from Sub-Saharan Africa (47%) and Asia (47%). Only 40% presented with symptoms, with gastrointestinal (18%) and cutaneous (17%) manifestations being the most common. Eosinophilia was observed in 43% (median [IQR]: 1103/mm3 [671-1536]), and ova were visualised in the urine of 2/50 (4.0%). Praziquantel treatment was administered to 92%, and 5 patients required retreatment. Follow-up data were available for 58 (80%) over a median period of 9 months [IQR 6-19.8], revealing a progressive decline in eosinophil count, IgE titres, and ELISA optical density.    Conclusion: In this series, the prevalence of schistosomiasis among migrant children was significant (10%), highlighting the importance of including serological tests in migrant health screening. The disease is largely asymptomatic, eosinophilia is often absent, and visualisation of ova in urine is exceedingly rare. Eosinophil count, IgE titres, and ELISA optical density could prove valuable as an initial approach for monitoring inflammation during follow-up assessments. What is Known: • The burden of disease related to schistosomiasis is significant, particulary in children, and it is advisable to screen this vulnerable population. What is New: • Eosinophilia may not be present in parasitic infections, so serological tests are crucial for screening migrant children. • Serological monitoring facilitates long-term management of migrant children with schistosomiasis.

Control of schistosomiasis by the selective competitive and predatory intervention of intermediate hosts: A mathematical modeling approach.

Schistosomiasis, a freshwater-borne neglected tropical disease, disproportionately affects impoverished communities mainly in the tropical regions. Transmission involves humans and intermediate host (IH) snails. This manuscript introduces a mathematical model to probe schistosomiasis dynamics and the role of non-host snail competitors and predators as biological control agents for IH snails. The numerical analyses include investigations into steady-state conditions and reproduction numbers associated with uncontrolled scenarios, as well as scenarios involving non-host snail competitors and/or predators. Sensitivity analysis reveals that increasing snail mortality rates is a key to reducing the IH snail population and control of the transmission. Results show that specific snail competitors and/or predators with strong competition/predation abilities reduce IH snails and the subsequent infectious cercaria populations, reduce the transmission, and possibly eradicate the disease, while those with weaker abilities allow disease persistence. Hence our findings advocate for the effectiveness of snail competitors with suitable competitive pressures and/or predators with appropriate predatory abilities as nature-based solutions for combating schistosomiasis, all while preserving IH snail biodiversity. However, if these strategies are implemented at insignificant levels, IH snails can dominate, and disease persistence may pose challenges. Thus, experimental screening of potential (native) snail competitors and/or predators is crucial to assess the likely behavior of biological agents and determine the optimal biological control measures for IH snails.