Schistosomiasis

Labeling of miracidium using fluorescent agents to visualize infection of schistosome in intermediate host snails

Schistosomiasis is a parasitic disease affecting more than 250 million people worldwide. Schistosomes infect humans by cercariae penetrating the skin in a freshwater environment. Findings obtained more than 100 years prior showed that miracidium develops into cercaria in freshwater snails, though detailed development dynamics have not been elucidated. Although results of histological analyses of development of schistosomes in snails were presented in our previous studies, findings obtained with dynamic imaging have yet to be reported. In the present study, imaging of schistosome infection and dynamics in snails occuring within a short period was performed using fluorescent labeling agents. Labeling of S. mansoni cercariae with carboxyfluorescein succinimidyl ester (CFSE) caused no toxicity, and allowed for monitoring of schistosome dynamics in snails for up to 10 days and release of infective cercariae without fluorescence in 40 days following infection.

Anthelmintic Potential of Conjugated Long-Chain Fatty Acids Isolated from the Bioluminescent Mushroom Neonothopanus gardneri

With praziquantel being the sole available drug for schistosomiasis, identifying novel anthelmintic agents is imperative. A chemical investigation of the fruiting body of the bioluminescent mushroom Neonothopanus gardneri Berk. resulted in the isolation of new conjugated long-chain fatty acids (8E,10E,12S,13S)-12,13-dihydroxy-7-oxo-octadeca-8,10-dienoic acid (1) and (7S,8S,9E,11E)-7,8-dihydroxy-13-oxo-octadeca-9,11-dienoic acid (2) and three previously described compounds, (7R,8R,9Z)-7,8-dihydroxyoctadec-9-enoic acid (3), (2E)-dec-2-ene-1,10-dioic acid (4), and a ketolactone marasmeno-1,15-dione (5). Their planar structures were elucidated based on 1D and 2D NMR and MS/MS spectroscopic analyses. Compound 3 displayed significant antiparasitic activity against Schistosoma mansoni ex vivo (EC50 < 10 μM). No toxicity was observed in mammalian cells or Caenorhabditis elegans.

Association of female genital schistosomiasis and human papillomavirus and cervical pre-cancer: a systematic review

BACKGROUND

S. haematobium is a recognized carcinogen and is associated with squamous cell carcinoma of the bladder. Its association with high-risk(HR) human papillomavirus (HPV) persistence, cervical pre-cancer and cervical cancer incidence has not been fully explored.

METHODS

We searched OvidSP MEDLINE, OvidSP Embase, Global Index Medicus, PubMed and the Wiley Cochrane library without date or language restrictions up to April 20, 2024 for abstracts evaluating the association of female genital schistosomiasis (FGS) with the prevalence, incidence or persistence of cervical HR-HPV, and incidence of histology-verified cervical pre-cancer or cancer. Cervical pre-cancer defined using cervical cytology or visual inspection with acetic acid (VIA) was also considered, but as lower quality evidence. We assessed the risk of bias of included studies using a modified Newcastle Ottawa scale. This study is registered on PROSPERO: CRD42023389301.

RESULTS

We identified 1,170 publications and six studies were eligible for inclusion. Five studies were cross sectional and 1 was prospective. The studies describe 1081 women living in sub-Saharan Africa. One study from Zimbabwe reported an increased risk of HR-HPV prevalence at baseline in women with composite-FGS compared to women without FGS (aOR 1.9, 95% CI 1.1 - 3.6, p = 0.03), however no association was seen after 5 years of follow-up. Another study from KwaZulu-Natal reported an increased odds of any HPV prevalence among women with visual-FGS compared to women without FGS (aOR 1.71 [1.14 - 2.56], p = 0.01). However, a study in Madagascar did not show increased odds of any HPV among women with visual-FGS compared to women without FGS (OR 1.0 [0.82 - 1.2). Of 4 studies evaluating the association of FGS and cervical pre-cancer, one reported an increased risk of VIA abnormalities in women with molecular-FGS compared to those without (aOR 6.08, 95% CI 1.58 - 23.37). Three studies did not report an association between FGS and cervical pre-cancer (cytology defined (n = 2) and histology defined (n = 1)).

CONCLUSION

There are limited and low quality data on the risk of HR-HPV infection and cervical pre-cancer and cancer among women with FGS. Given limited data, it was not possible to confirm or exclude an association between FGS and HPV, cervical pre-cancer, and cervical cancer and additional research is needed.

A Guide to Pathophysiology, Signaling Pathways, and Preclinical Models of Liver Fibrosis

Liver fibrosis is potentially a reversible form of liver disease that evolved from the early stage of liver scarring as a consequence of chronic liver injuries. Recurrent injuries in the liver without any appropriate medication cause the injuries to get intense and deeper, which gradually leads to the progression of irreversible cirrhosis or carcinoma. Unfortunately, there are no approved treatment strategies for reversing hepatic fibrosis, making it one of the significant risk factors for developing advanced liver disorders and liver disease-associated mortality. Consequently, the interpretation of the fundamental mechanisms, etiology, and pathogenesis is crucial for identifying the potential therapeutic target as well as evaluating novel anti-fibrotic therapy. However, despite innumerable research, the functional mechanism and disease characteristics are still obscure. To accelerate the understanding of underlying disease pathophysiology, molecular pathways and disease progression mechanism, it is crucial to mimic human liver disease through the formation of precise disease models. Although various in vitro and in vivo liver fibrotic models have emerged and developed already, a perfect clinical model replicating human liver diseases is yet to be established, which is one of the major challenges in discovering proper therapeutics. This review paper will shed light on pathophysiology, signaling pathways, preclinical models of liver fibrosis, and their limitations.

Simple preservation of schistosome eggs with high infectivity up to 12 weeks

The lifecycle of schistosomes must be continuously maintained to clarify and understand this parasite in various aspects in laboratory settings. In the previous studies by other researchers, preservation of schistosome larvae or eggs was attempted by freezing with liquid nitrogen or organic chemicals, but frozen schistosomes were substantially impaired. The present study was conducted to determine whether schistosome eggs can be preserved under a non-frozen condition. The results showed that Schistosoma mansoni eggs could be maintained in phosphate-buffered saline at 4 °C, with a high level of infectivity of miracidia to freshwater snails thereafter. Furthermore, the egg hatchability was maintained for up to 12 weeks with weekly exchanges of the medium. The cercariae derived from snails infected with miracidia from preserved eggs were highly infective to mice. This simple schistosome egg preservation method allow researchers to maintain the schistosome lifecycle without freezing or other special procedures.

Contextual factors influencing schistosomiasis treatment and identification of delivery platforms for arpraziquantel in hard-to-reach areas and populations in Homa Bay County, Kenya

A new formulation of praziquantel, arpraziquantel (arPZQ), has been developed for preschool-aged children (PSAC) to fill the treatment gap for this age group in schistosomiasis control and elimination programs. There is now a priority to ensure that the drug reaches all at-risk PSAC in endemic areas, including hard-to-reach areas and populations. This study aimed to determine schistosomiasis treatment-related contextual factors among fishermen and island populations in Homa Bay County, Kenya, and to identify a suitable platform to deliver arPZQ. We conducted a generic qualitative study using two case study interviews with parents/caregivers living with disability caring for children ≤5 years,18 focus group discussions (FGDs) with parents/caregivers of children ≤5 years (each with 8-10 participants), 14 key informant interviews (KIIs) with various government agencies, and unstructured observations. The data were analyzed using thematic analysis. The case study interviews and FGDs revealed awareness of schistosomiasis among community members but limited knowledge of transmission risk factors. Lake water and open defecation were the main predisposing factors to infection. We observed poor health-seeking behavior in the community due to inaccessibility of quality healthcare services, resulting from health system level, population level, and geographic barriers. Despite these barriers, community members reported positive experiences with previous PZQ mass drug administration (MDAs) and other innovative healthcare programs, and expressed willingness to participate in future MDAs, including with arPZQ. Based on the reported barriers, the door-to-door distribution approach by community health promoters was proposed by parents and key informants as the most feasible platform for community sensitization, mobilization, and arPZQ delivery. To achieve high arPZQ treatment coverage for all at-risk PSAC, and promote ownership and sustainability of the program, the door-to-door approach is the most promising platform to deliver treatment and public health promotion in marginalized hard-to-reach island populations of Lake Victoria, Kenya.

Benzimidazole analogues active against adult Schistosoma mansoni: SAR analyses, In vivo efficacy in mice, and preliminary mechanistic studies as potential inhibitors of hemozoin formation

For over three decades, praziquantel (PZQ) has been the mainstay chemotherapy for prevention and treatment of schistosomiasis. The excessive use of PZQ, coupled with the lack of advanced drug candidates in the current anti-schistosomiasis drug development pipeline, emphasizes the genuine need for new drugs. In the current work, we investigated the antischistosomal potential of a new series of compounds derived from the privileged benzimidazole scaffold, which exhibited low micromolar IC50 potency in the range of 1.0-2.7 μM against Schistosomamansoni adult worms, in vitro. However, representative compounds showed low in vivo activity. One compound (15) reduced worm burden by 51.9 %, although the reduction was not statistically significant. Furthermore, by invoking inhibition of hemozoin formation, an immutable drug target in Schistosoma adult worms, as a likely contributing mode of action, we observed that the most potent analogues were equally potent inhibitors of β-hematin (synthetic hemozoin) formation in a cell-free assay.

Population genetics and molecular xenomonitoring of Biomphalaria freshwater snails along the southern shoreline of Lake Malawi, Malawi

BACKGROUND

Intestinal schistosomiasis was confirmed endemic in Mangochi District, Malawi, in May of 2018 following an unexpected encounter with discreet populations of Biomphalaria spp. freshwater snails during routine malacological surveillance activities. Since then, only limited malacological surveillance of Biomphalaria has been carried out, and so the distribution of Biomphalaria populations in this area is currently unclear. Additionally, sites of active Schistosoma mansoni transmission in this area are also unknown. In the present study, through extensive malacological surveillance, we aimed to formally document the distribution of Biomphalaria in Mangochi District. We also aimed to identify active intestinal schistosomiasis transmission sites in this area through subjecting all collected Biomphalaria to a recently developed S. mansoni-specific molecular xenomonitoring PCR.

METHODS

Three malacological surveys were carried out along the southern shoreline of Lake Malawi, Mangochi District, Malawi, in November 2021, July 2022 and October/November 2022. All collected Biomphalaria were subjected to cercarial shedding analysis to identify active Schistosoma infections. Shed cercariae were then genotyped to species level using a standard multi-locus PCR and Sanger sequencing protocol. Following this, a subset of Biomphalaria from each collection site were also genotyped to species level using a standard PCR and Sanger sequencing protocol. All collected Biomphalaria were then subjected to a recently developed S. mansoni-specific molecular xenomonitoring PCR to identify infected, but non-shedding, Biomphalaria.

RESULTS

A total of 589 Biomphalaria were collected across all three surveys. One single Biomphalaria (0.17%) specimen was found to be actively shedding Schistosoma cercariae, which were molecularly confirmed as S. mansoni. All genotyped Biomphalaria (n = 42) were molecularly identified as B. pfeifferi. A further 19 Biomphalaria specimens, collected from four different surveillance sites, were found to be infected with S. mansoni through molecular xenomonitoring. Intestinal schistosomiasis transmission was therefore identified at four different foci in Mangochi District.

CONCLUSIONS

Our study highlights the importance of molecular approaches to investigate Biomphalaria populations and monitor Biomphalaria-associated intestinal schistosomiasis transmission in endemic areas. As such, the continued development and use of such approaches, in particular the development and use of molecular xenomonitoring assays that can be carried out in resource-poor schistosomiasis-endemic settings, is encouraged. The revision of ongoing schistosomiasis control programmes in Mangochi District, in line with WHO recommendations, is also encouraged.

The retinoic acid family-like nuclear receptor SmRAR identified by single-cell transcriptomics of ovarian cells controls oocyte differentiation in Schistosoma mansoni

Studies on transcription regulation in platyhelminth development are scarce, especially for parasitic flatworms. Here, we employed single-cell transcriptomics to identify genes involved in reproductive development in the trematode model Schistosoma mansoni. This parasite causes schistosomiasis, a major neglected infectious disease affecting >240 million people worldwide. The pathology of schistosomiasis is closely associated with schistosome eggs deposited in host organs including the liver. Unlike other trematodes, schistosomes exhibit distinct sexes, with egg production reliant on the pairing-dependent maturation of female reproductive organs. Despite this significance, the molecular mechanisms underlying ovary development and oocyte differentiation remain largely unexplored. Utilizing an organ isolation approach for S. mansoni, we extracted ovaries of paired females followed by single-cell RNA sequencing (RNA-seq) with disassociated oocytes. A total of 1967 oocytes expressing 7872 genes passed quality control (QC) filtering. Unsupervised clustering revealed four distinct cell clusters: somatic, germ cells and progeny, intermediate and late germ cells. Among distinct marker genes for each cluster, we identified a hitherto uncharacterized transcription factor of the retinoic acid receptor family, SmRAR. Functional analyses of SmRAR and associated genes like Smmeiob (meiosis-specific, oligonucleotide/oligosaccharide binding motif (OB) domain-containing) demonstrated their pairing-dependent and ovary-preferential expression and their decisive roles in oocyte differentiation of S. mansoni.

Development of a latex microsphere-based lateral flow immunoassay for the diagnosis of schistosomiasis japonica

BACKGROUND

Zoonotic schistosomiasis, caused by Schistosoma japonicum, is prevalent in China, the Philippines and Indonesia. Rapid point-of-care (POC) diagnostics are attractive and promising tools for evaluating the efficacy of intervention strategies for schistosomiasis control.

METHODOLOGY

The diagnostic potential of five recombinant antigens was tested by enzyme-linked immunosorbent assay (ELISA) using sera from individuals with positive Kato-Katz (KK) results for S. japonicum (n = 28) and non-endemic controls (n = 12). A latex microsphere (LM)-based lateral flow immunoassay (LFIA) incorporating the recombinant SjSAP4 (rSjSAP4) was developed for the diagnosis of schistosomiasis japonica. The test conditions including diluent, dilution factor and reaction time, were optimised for the developed LFIA. Under the optimised conditions, serum samples from individuals living in a barangay endemic for S. japonicum (n = 549) and non-endemic controls (n = 50) were tested with the established LFIA cassettes. The results were imaged by a smartphone and analysed by the ImageJ program. The intensity ratio of the test line to the control line (T/C ratio) was calculated for each cassette.

MAIN FINDINGS

ELISA confirmed that rSjSAP4 was the optimal candidate for serological diagnosis of schistosomiasis japonica. Under optimal testing conditions, the developed LFIA strips had a sensitivity of 80.6% and a specificity of 98.0% at a cut-off T/C ratio of 0.1031. Moreover, the results of the LM-based LFIA was positively correlated with those obtained from the rSjSAP4-ELISA (r = 0.8270, 95% CI, 0.7990-0.8514; p < 0.0001). The schistosomiasis prevalence determined by the LFIA strips was about 1.8 times greater than that obtained with the 6-slide KK procedure performed on three stool samples.

CONCLUSIONS/SIGNIFICANCE

The developed LFIA represents a POC diagnostic tool that is suitable for onsite screening of human S. japonicum infection with minimal equipment needed. The established immunochromatographic assay complies with most of the WHO's ASSURED criteria for POC diagnostics.

Differential murine responses to Schistosoma mansoni eggs in the liver and small intestine lead to downmodulation of hepatic but not intestinal periovular granulomas

To control schistosomiasis mansoni, it is important to attempt preventing the worms' egg-induced pathology in the liver and limiting pathogen transmission following egg exit from the intestines to the exterior. Therefore, the present study aimed to clarify the reasons behind the decades-long riddle of periovular granulomas downmodulation in the liver, but not the small intestine, with the progression of murine schistosomiasis mansoni. Outbred female CD-1 mice were percutaneously exposed to 15 Schistosoma mansoni cercariae. The liver and small intestine were collected from mice harboring a minimum of a worm couple at 8, 12, 16, and 20 weeks post-infection, assessed for egg counts/g and histopathological changes, and used to prepare Triton X-100 extracts. Content of cytokines, saturated and unsaturated fatty acids, triglycerides, cholesterol, reactive oxygen species, and uric acid per mg tissue extract proteins were evaluated using capture enzyme-linked immunosorbent assays, gas chromatography-flame ionization detector, and standard commercially available reagents, respectively. Examination of hematoxylin-eosin-stained tissue sections confirmed the decrease in size and changes in cellular composition of periovular granulomas in the liver but not the small intestine, associated with wide differences in released cytokines types and amounts, and content of the bioactive lipids, arachidonic and docosahexaenoic acids, reactive oxygen species, and uric acid. The results together disclosed that the downmodulation of hepatic, but not the small intestine, circumoval granulomas with the progression of murine S. mansoni naturally results from site- and tissue- specific immunological and biochemical responses to the egg-derived antigens and molecules and suggested that the intestines appear to harbor immune-privileged sites.

Cerebral schistosomiasis in a 3-year-old girl due to Schistosoma japonicum: a case report

Introduction

Cerebral schistosomiasis is a rare but severe manifestation of Schistosoma japonicum infection, often leading to significant neurological impairment. This case report details the clinical presentation, diagnostic challenges, and treatment of a 3-year-old girl with cerebral schistosomiasis in Sichuan, China.

Case description

A 3-year-old girl from a rural area in Sichuan, China, presented with a 3-month history of unstable walking, left facial paralysis, drowsiness, and intermittent fever. Brain MRI revealed giant polycystic lesions in the right temporal, parietal, and occipital lobes, suggestive of an abscess with ependymitis. Despite no history of travel to endemic areas or known freshwater exposure, the patient was diagnosed with cerebral schistosomiasis due to Schistosoma japonicum based on histological examination and metagenomic next-generation sequencing (mNGS) of brain tissue obtained through surgery. The patient underwent surgical resection of the lesions and received two courses of praziquantel combined with corticosteroids and anticonvulsants. Despite residual left-sided hemiplegia, her cognitive function remained comparable to that of her peers, and no recurrence of the disease was observed over three years of follow-up.

Conclusion

This case underscores the diagnostic challenges of cerebral schistosomiasis, particularly in non-endemic areas or in the absence of a clear history of freshwater exposure. Early surgical intervention combined with praziquantel treatment can lead to favorable outcomes, even in severe cases with extensive brain involvement.

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

BACKGROUND

WHO guidelines for schistosomiasis-related morbidity control and elimination rely on current infection as a proxy indicator for morbidity. We evaluated these guidelines within the context of repeated mass drug administration and periportal fibrosis attributable to chronic intestinal schistosomiasis.

METHODS

We examined 1442 households randomly sampled from 38 villages in Buliisa, Pakwach, and Mayuge districts of Uganda within the SchistoTrack cohort. Periportal fibrosis was diagnosed in 2834 individuals aged 5-90 years using ultrasound and image patterns C-F from the Niamey protocol. Schistosoma mansoni status and intensity were diagnosed by Kato-Katz microscopy and point-of-care circulating cathodic antigen tests. Schistosome infection, co-infections, and comorbidities were examined as exposures for periportal fibrosis. Multivariable logistic regressions were run with SEs clustered by household.

FINDINGS

Between Jan 6 and Feb 3, 2022, 342 (12·1%) of 2834 participants were diagnosed with periportal fibrosis. By Kato-Katz microscopy, 1229 (43·4%) of 2834 participants were infected. 1863 (65·7%) of 2834 participants had trace positive point-of-care circulating cathodic antigen tests, which was higher than prevalence by Kato-Katz microscopy, and 1158 (40·9%) of 2834 participants had trace negative point-of-care circulating cathodic antigen tests. Individual schistosome status, intensity, and prevalence of heavy intensity infections of less than 1% and less than 5% were not correlated with periportal fibrosis likelihood or village prevalence. Periportal fibrosis likelihood linearly increased with age from age 5 years to age 25 years, non-linearly increased from age 26 years to age 45 years, attenuated or remained unchanged from age 46 years to age 60 years, and steadily decreased past 60 years of age. History of liver diseases, HIV, and ultrasound-detected chronic hepatitis or early cirrhosis-like disease were associated with more than two-times increased periportal fibrosis likelihood.

INTERPRETATION

WHO guidelines reliant on current schistosome status and intensity are uninformative for identifying probable cases or communities with periportal fibrosis. History of HIV and underlying chronic hepatitis or early cirrhosis-like disease are risk factors that could be investigated for periportal fibrosis surveillance and management.

FUNDING

NDPH Pump Priming Fund, Wellcome Trust, John Fell Fund, Robertson Foundation, and UK Research and Innovation Engineering and Physical Sciences Research Council.

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

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

Mechanisms of lung endothelial cell injury and survival in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive, chronic, and incurable inflammatory pulmonary vascular disease characterized by significant sex bias and largely unexplored microbial-associated molecular mechanisms that may influence its development and sex prevalence across various subgroups. PAH can be subclassified as idiopathic, heritable, or associated with conditions such as connective tissue diseases, congenital heart defects, liver disease, infections, and chronic exposure to drugs or toxins. During PAH progression, lung vascular endothelial cells (ECs) undergo dramatic morphofunctional transformations in response to acute and chronic inflammation. These transformations include the appearance and expansion of abnormal vascular cell phenotypes such as those derived from apoptosis-resistant cell growth and endothelial-to-mesenchymal transition (EndoMT). Compelling evidence indicates that these endothelial phenotypes seem to be triggered by chronic lung vascular injury and dysfunction, often characterized by reduced secretion of vasoactive molecules like nitric oxide (NO) and exacerbated response to vasoconstrictors such as Endothelin-1 (ET-1), both long-term known contributors of PAH pathogenesis. This review sheds light on the mechanisms of EC dysfunction, apoptosis, and EndoMT in PAH, aiming to unravel the intricate interactions between ECs, pathogens, and other cell types that drive the onset and progression of this devastating disease. Ultimately, we hope to provide an overview of the complex functions of lung vascular ECs in PAH, inspiring novel therapeutic strategies that target these dysfunctional cells to improve the treatment landscape for PAH, particularly in the face of current and emerging global pathogenic threats.

In vivo antischistosomal efficacy of Porcelia ponderosa γ-lactones

BACKGROUND

Schistosomiasis, caused by the parasitic blood fluke Schistosoma mansoni, is a significant global health concern, particularly in tropical and subtropical regions. The available chemotherapeutic drug is restricted to praziquantel with present problems related to efficacy, toxicity and resistance, justifying the search for new drugs. Different natural products, including γ-lactones, have demonstrated anthelmintic activity. Thus, in this study, new γ-lactones from Porcelia ponderosa were investigated for their anti-S. mansoni effects in vitro and in vivo.

PURPOSE

To evaluate the therapeutical potential against S. mansoni of the mixture of γ-lactones 1 + 2 obtained from Porcelia ponderosa seeds.

STUDY DESIGN AND METHODS

The precipitate formed during the concentration of CH2Cl2 extract from seeds of P. ponderosa showed to be composed by a mixture of the new γ-lactones 1 + 2 (in a ratio 77:23) which were chemically characterized using NMR and ESI-HRMS. This mixture was evaluated in vitro and in vivo against S. mansoni, using a murine model of schistosomiasis. Additionally, toxicity of the mixture of 1 + 2 (77:23) was determined using mammalian cell lines (in vitro) or the model organism Caenorhabditis elegans (in vivo).

RESULTS

Seeds of P. ponderosa afforded a mixture of two unreported γ-lactones, 3‑hydroxy-4-methylene-2-(tetracosa-17'Z,23'-diene-13',15'-diynyl)‑but-2-enolide (1) and 3‑hydroxy-4-methylene-2-(tetracos-17'Z-ene-13',15'-diynyl)‑but-2-enolide (2). Initially, the antischistosomal activity of the mixture of 1 + 2 (77:23) was investigated in vitro, and obtained results demonstrate reduced activity against Schistosoma mansoni worms (EC50 of 83.3 μg/ml) in comparison to positive control praziquantel (EC50 of 1.5 μg/ml). However, when tested in vivo using oral administration at 400 mg kg-1, the standard dose used in the murine model of schistosomiasis, the mixture of 1 + 2 (77:23) revealed expressive reductions in both worm burden (65.7 %) and egg production (97.2 %), similar of those observed to praziquantel (89.7 % and 91.5 %, respectively). On the other hand, when treated using 200 and 100 mg kg-1, reductions in worm burden (25.7 and 12.4 %) and egg production (33.6 and 13.3 %) were also observed. Importantly, the mixture of 1 + 2 (77:23) exhibited no toxicity using mammalian cell lines (in vitro) or C. elegans (in vivo).

CONCLUSION

Considering the promising in vivo activity of γ-lactones from P. ponderosa, the mixture of 1 + 2 (77:23) can be considered as promising candidate for the development of novel antischistosomal therapeutics, underscoring the importance of biodiversity exploration in the search for effective treatments against neglected tropical diseases.

Single-Dose Drug Development Candidate for Schistosomiasis

Aryl hydantoins were identified in the early 1980s as a promising antischistosomal chemotype. However, as exemplified by Ro 13-3978, this compound series produced antiandrogenic side effects on the host, a not unexpected outcome given their structural similarity to the antiandrogenic drug nilutamide. The two key advances in our optimization of Ro 13-3978 were swapping the aryl trifluoromethyl substituent with a difluoroethyl to abolish antiandrogenic effects and replacing the hydrogen atoms of the gem-dimethyl substructure with deuterium atoms to increase metabolic stability. Combining these two structural changes led to the discovery of single-dose drug candidate AR102, a compound with potent, selective, and broad-spectrum activity against schistosomes, a long pharmacokinetic half-life in preclinical species, and an acceptable safety profile.

Global burden of zoonotic infectious diseases of poverty, 1990-2021

BACKGROUND

The zoonotic infectious diseases of poverty (zIDPs) are a group of diseases contributing to global poverty, with significant impacts on a substantial population. This study aims to describe the global, regional, and national burden of zIDPs-schistosomiasis, cystic echinococcosis, cysticercosis, and food-borne trematodiases (FBTs)-to support policy making and resource allocation for their control and elimination.

METHODS

Data of zIDPs from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 were retrieved from 1990 to 2021. The age-standardized prevalence rate (ASPR), age-standardized mortality rate (ASMR), and age-standardized disability-adjusted life-year (DALY) rate were described and the estimated annual percentage changes (EAPCs) were calculated to quantify their burden and temporal trends. Spearman correlation analysis was conducted to examine the relationship between age-standardized rates and Socio-demographic Index (SDI).

RESULTS

In 2021, these zIDPs exhibited a certain level of ASPRs and age-standardized DALY rates, while maintaining relatively low ASMRs. Noticeably, schistosomiasis presented the highest ASPR of 1914.299 (95% UI: 1378.920, 2510.853 per 100,000 population) and an age-standardized DALY rate of 21.895 (95% UI: 12.937, 37.278 per 100,000 population) among the zIDPs. The tapestry of burden-woven predominantly through low and lower-middle SDI regions-stretched across Africa, Latin America, and parts of Asia. From 1990 to 2021, a kaleidoscopic shift was observed globally as ASPRs, ASMRs, and age-standardized DALY rates declined significantly, as reflected by the EAPC values. Negative correlations were observed between the ASPRs, ASMRs, age-standardized DALY rates of schistosomiasis (r value = - 0.610, - 0.622 and - 0.610), cystic echinococcosis (- 0.676 of ASMR, - 0.550 of age-standardized DALYs), cysticercosis (- 0.420, - 0.797 and - 0.591) and the SDI. In contrast, a slight positive correlation was noted between the ASPR, age-standardized DALY rates of FBTs and SDI with r value of 0.221 and 0.213, respectively.

CONCLUSION

The burden of zIDPs declined across almost all endemic regions from 1990 to 2021, yet still predominated in low and low-middle SDI regions. Substantial challenges exist to achieve the goal of control and elimination of zIDPs, and integrated approaches based on One Health need to be strengthened to improve health outcomes.

Mapping schistosomiasis risk landscapes and implications for disease control: A case study for low endemic areas in the Middle Paranapanema river basin, São Paulo, Brazil

BACKGROUND

Schistosomiasis, a chronic parasitic disease, remains a public health issue in tropical and subtropical regions, especially in low and moderate-income countries lacking assured access to safe water and proper sanitation. A national prevalence survey carried out by the Brazilian Ministry of Health from 2011 to 2015 found a decrease in human infection rates to 1%, with 19 out of 26 states still classified as endemic areas. There is a risk of schistosomiasis reemerging as a public health concern in low-endemic regions. This study proposes an integrated landscape-based approach to aid surveillance and control strategies for schistosomiasis in low-endemic areas.

METHODOLOGY/PRINCIPAL FINDINGS

In the Middle Paranapanema river basin, specific landscapes linked to schistosomiasis were identified using a comprehensive methodology. This approach merged remote sensing, environmental, socioeconomic, epidemiological, and malacological data. A team of experts identified ten distinct landscape categories associated with varying levels of schistosomiasis transmission potential. These categories were used to train a supervised classification machine learning algorithm, resulting in a 92.5% overall accuracy and a 6.5% classification error. Evaluation revealed that 74.6% of collected snails from water collections in five key municipalities within the basin belonged to landscape types with higher potential for S. mansoni infection. Landscape connectivity metrics were also analysed.

CONCLUSIONS/SIGNIFICANCE

This study highlights the role of integrated landscape-based analyses in informing strategies for eliminating schistosomiasis. The methodology has produced new schistosomiasis risk maps covering the entire basin. The region's low endemicity can be partly explained by the limited connectivity among grouped landscape-units more prone to triggering schistosomiasis transmission. Nevertheless, changes in social, economic, and environmental landscapes, especially those linked to the rising pace of incomplete urbanization processes in the region, have the potential to increase risk of schistosomiasis transmission. This study will help target interventions to bring the region closer to schistosomiasis elimination.

Oral Administration of Kaempferol Isolated from Baccharis Mattogrosensis Enables In Vivo Activity Against Schistosoma Mansoni

Baccharis mattogrosensis is a species from Asteraceae which has been used in Brazilian folk medicine to treatment of several illnesses, including those caused by parasites. In the present work, the MeOH extract of aerial parts of B. mattogrosensis was subjected to chromatographic fractionation to afford three flavonoids: apigenin (1), quercetin (2), and kaempferol (3) as well as a mixture three chlorogenic acids: 3,4-O-dicaffeoylquinic (4), 3,5-O-dicaffeoylquinic (5), and 4,5-O-dicaffeoylquinic (6) acids. When tested in vitro, kaempferol (3) exhibited activity against Schistosoma mansoni with EC50=81.86 μM, whereas compounds 1, 2, 4-6 showed to be inactives. Considering this result, the effects of kaempferol (3) against S. mansoni infection using an experimental approach (in vivo assay) was tested at first time. Using a single oral dose (400 mg/kg) of kaempferol (3) to S. mansoni-infected mice reduced the worm burden by 25.5 %. Similarly, the number of eggs, which are responsible for a variety of pathologies and transmission of schistosomiasis, was decreased by 28.8 % in treated mice. Collectively, although kaempferol (3) is partially active when administered orally in a mouse model of schistosomiasis, our results suggest that this compound could be, in future studies, administered in different forms, such as nanoformulation.

Schistosoma antigens: A future clinical magic bullet for autoimmune diseases?

Autoimmune diseases are characterized by dysregulated immunity against self-antigens. Current treatment of autoimmune diseases largely relies on suppressing host immunity to prevent excessive inflammation. Other immunotherapy options, such as cytokine or cell-targeted therapies, have also been used. However, most patients do not benefit from these therapies as recurrence of the disease usually occurs. Therefore, more effort is needed to find alternative immune therapeutics. Schistosoma infection has been a significant public health problem in most developing countries. Schistosoma parasites produce eggs that continuously secrete soluble egg antigen (SEA), which is a known modulator of host immune responses by enhancing Th2 immunity and alleviating outcomes of Th1 and Th17 responses. Recently, SEA has shown promise in treating autoimmune disorders due to their substantial immune-regulatory effects. Despite this interest, how these antigens modulate human immunity demonstrates only limited pieces of evidence, and whether there is potential for Schistosoma antigens in other diseases in the future remains an unsolved question. This review discusses how SEA modulates human immune responses and its potential for development as a novel immunotherapeutic for autoimmune diseases. We also discuss the immune modulatory effects of other non-SEA schistosome antigens at different stages of the parasite's life cycle.

Research progress in the treatment of schistosomiasis with traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Schistosomiasis, caused by infection with organisms of the Schistoma genus, is a parasitic and infectious disease that poses a significant risk to human health. Schistosomiasis has been a widespread issue in China for at least 2000 years. Traditional Chinese medicine (TCM) has a rich history of treating this disease, and the significant theoretical and practical knowledge attained therein may be useful in modern practice.

AIM OF THE STUDY

To comprehensively review TCM for the treatment of schistosomiasis, summarize the molecular basis, mechanism of action, active ingredients and formulas of TCM, and clarify the value of TCM for expanding drug options for the clinical treatment of schistosomiasis.

MATERIALS AND METHODS

In PubMed, Web of Science, ScienceDirect, Google Scholar and CNKI databases, "Schistosomiasis", "Schistosoma mansoni", "Schistosoma japonicum", "Liver fibrosis" and "Granuloma" were used as the key words. Information related to in vivo animal studies and clinical studies of TCM for the treatment of schistosomiasis in the past 25 years was retrieved, and the inclusion criteria focused on medicinal plants that had a history of use in China.

RESULTS

In this study, we collected and organized a large amount of literature on the treatment of schistosomiasis by TCM. TCM exerts therapeutic effects through antischistosomal and immunomodulatory effects, suppresses HSC activation and proliferation, reduces ECM deposition, and inhibits oxidative stress and other activities. The treatment of schistosomiasis by TCM has a unique advantage, especially for the treatment of schistosomal liver fibrosis, and the treatment of schistosomiasis with TCM in combination with praziquantel is superior to monotherapy.

CONCLUSION

Schistosomiasis remains a global public health problem, and TCM has made significant progress in the prevention and treatment of schistosomiasis and is a potential source of drugs for the treatment of schistosomiasis. However, research on drug screening and the mechanism of action of TCM for the treatment of schistosomiasis is lacking, and further studies and research are needed.

Community Mobilisation for Human Sample Collection in Sensitive Communities: Experiences from Granular Mapping of Schistosomiasis and Soil-Transmitted Helminths in Ekiti State, South West, Nigeria

Community mobilisation is a vital process for raising awareness and increasing participation in healthcare interventions, research, and programmes that require human sample collection and mass management. In this report, we present the community mobilisation approach undertaken for the implementation of the operational mapping and assessment of granular schistosomiasis and soil-transmitted helminths in Ekiti State, Nigeria. The mobilisation was conducted in 177 communities/wards of the 16 local government areas. A total of 15,340 urine and stool samples were collected in 34 days. The efficacy and success of the strategy were evaluated through the following three performance metrics: community compliance rate, the participant response rate at the community level, and the overall compliance response rate of the four most sensitive LGAs. Community compliance was 93.7% as sample collection was denied in nine communities and two other communities demanded the return of the collected samples despite our mobilisation effort because of cultural bias and myths that connect the collection of stool and urine samples to ritual activities in the local context. The participant response rate at the community level was 86.7%. Three of the four sensitive LGAs (based on previous assessment programmes) demonstrated satisfactory compliance rates of 100%, while a response rate of 64.0% was computed for one of the LGAs. We believe our approach contributed to effective community mobilisation and awareness and that the developed model has the potential to improve participation rates in large healthcare assessments and intervention programmes.

Depression in the schistosomiasis japonica population based on the PHQ-9 scale: a cross-sectional survey from Jiangxi Province, China

Depression is the second leading-cause of disability in China. Although studies have shown that more than 80% of patients with advanced schistosomiasis (AS) suffer from anxiety and depression, these study groups are all hospitalized patients with AS and do not represent the extent of the disease in the whole group. To our knowledge, there are no studies assessing the severity of depression in patients with other forms of schistosomiasis japonicum. Therefore, it is necessary to evaluate the occurrence and potential risk factors of depression in the schistosomiasis endemic population. This cross-sectional study was conducted in Jiangxi Province, where schistosomiasis is relatively common in China, as the investigation site. The Patient Health Questionnaire-9 (PHQ-9) scale was selected to assess the depressive symptoms in the study population. At the same time, basic personal information of the research subjects and relevant socio-economics and schistosomiasis endemic area indicators were collected. The survey results show that AS has the highest incidence of depression (34.35%), while non-advanced schistosomiasis (N-AS) and control group (CG) have 22.35% and 22.24% respectively; the incidence of depression in AS is significantly higher than in N-AS and CG, while there is no statistical significance in the comparison between N-AS and CG; the incidence of mild depressive symptoms accounts for 61.08%-75.54% of the total incidence of depression in different groups; multivariate analysis shows that the occurrence of moderate/severe depressive symptoms in the AS group was significantly related to above 60 years old, male, the combination of other serious diseases, personal financial difficulties, and marshland and lake endemic areas. In the N-AS group, the occurrence of moderate/severe depressive symptoms was significantly related to the combination of other serious diseases, personal financial difficulties, significant correlation between marshland and lake endemic areas and the level of control of schistosomiasis epidemics. In conclusion, depression is still relatively common among patients with schistosomiasis patients, especially those with AS. It is recommended that the government and relevant departments consider mental health care when developing prevention and control work in schistosomiasis-endemic areas, in order to effectively protect the physical and mental health of schistosomiasis patients and residents in endemic areas.

Association of Antibodies to Helminth Defense Molecule 1 With Inflammation, Organomegaly, and Decreased Nutritional Status in Schistosomiasis Japonica

Immunomodulation enhances parasite fitness by reducing inflammation-induced morbidity in the mammalian host, as well as by attenuating parasite-targeting immune responses. Using a whole-proteome differential screening method, we identified Schistosoma japonicum helminth defense molecule 1 (SjHDM-1) as a target of antibodies expressed by S. japonicum-resistant but not S. japonicum-susceptible individuals. In a longitudinal cohort study (n = 644) conducted in a S. japonicum-endemic region of the Philippines, antibody levels to SjHDM-1 did not predict resistance to reinfection but were associated with increased measures of inflammation. Individuals with high levels of anti-SjHDM-1 immunoglobulin G had higher levels of C-reactive protein than those with low anti-SjHDM-1. High anti-SjHDM-1 immunoglobulin G responses were also associated with reduced biomarkers of nutritional status (albumin), as well as decreased anthropometric measures of nutritional status (weight-for-age and height-for-age z scores) and increased measures of hepatomegaly. Our results suggest that anti-SjHDM-1 responses inhibit the immunomodulatory function of SjHDM-1, resulting in increased morbidity rates.

Time-course whole blood transcriptome profiling provides new insights into Microtus fortis natural resistance mechanism to Schistosoma japonicum

Microtus fortis is known as a non-susceptible animal host of S. japonicum. A better understanding of this animal immune defense mechanism during the early stage of infection may offer an alternative route for vaccine development or therapy. Here, we analyzed the whole blood transcriptome of M. fortis using next-generation sequencing (NGS) to identify immune genes of biological relevance that might be involved in the mechanism of its resistance. The blood samples were collected from uninfected animals (control group) and infected animals at different time points (3, 7, 10 and 14 days post-infection). We identified 5310 sequences as unigenes and successfully annotated 4636 of them. The immune response was more intense at 10 dpi. The upregulated genes at this time point were mainly activated in the TNF and NF-kappa B signaling pathways, Th1, Th2and Th17 cell differentiation as well as cytokine-cytokine receptor interaction. Based on the differentially expressed genes analysis, we report that the IF27L2B, RETN, PGRP, IFI35, TYROBP, S100A8, S100A11, CD162, CD88, CYBA, and LBP could play important roles in the mechanism of M. fortis resistance.

Rapid on-site detection of echinococcosis and schistosomiasis based on RPA

BACKGROUND

Echinococcosis and schistosomiasis, caused by parasitic worms, pose significant threats to millions of people in the world. Rapid and effective pathogen detection and epidemic control by public health authorities are urgently needed.

OBJECTIVES

In this study, we aimed to develop rapid on-site detection method to detect echinococcosis and schistosomiasis.

METHODS

Recombinase polymerase amplification (RPA) was utilised to examine its efficacy of detection of echinococcosis and schistosomiasis.

FINDINGS

The detection probes for RPA were created through comparing parasitic genomes from international genomic data and the sequences generated by our group. We established an optimised RPA on-site testing platform, which significantly reduces the detection time (less than 30 min) and simplifies the operation (free of expensive equipment) as compared to traditional polymerase chain reaction (PCR) method.

MAIN CONCLUSIONS

This RPA detection platform in our study for identifying echinococcosis or schistosomiasis pathogens would be greatly applicable for epidemic investigation, border screening, and early clinical diagnosis.

Potential associations between Schistosoma mansoni infection and physico-chemical characteristics and water-related human activities in Côte d'Ivoire: a cross-sectional study

BACKGROUND

Schistosomiasis remains a public health problem, particularly in sub-Saharan Africa. The disease is intimately connected to poverty and environmental factors. Our research was readily embedded into a multi-country schistosomiasis oversampling study. The aim of the study presented here was to determine the prevalence of Schistosoma mansoni and to investigate the role of water body characteristics and water-related human activities in disease transmission.

METHODS

In August and September 2022, a cross-sectional study was conducted in the western part of Côte d'Ivoire. Stool and urine samples were collected from 1602 and 1729 children aged 5-14 years, respectively, in 65 villages in the health districts of Biankouma, Ouaninou and Touba. Additionally, data were collected from direct observation of water-related activities at water bodies and interviews conducted with community leaders and health workers. The prevalence and risk factors for Schistosoma infection were assessed using generalised estimating equation models.

RESULTS

The prevalence ofS. mansoni and S. haematobium were 27.4% (95% confidence interval [CI] 21.5-34.3%) and 0.1% (95% CI 0.03-0.5%), respectively. Low prevalence of soil-transmitted helminths was observed with 2.4%, 0.4% and 0.2% for hookworm, Trichuris trichiura and Ascaris lumbricoides, respectively. At the health district level, we found S. mansoni prevalence of 34.4% (95% CI 25.0-45.3%), 34.3% (95% CI 24.0-46.2%) and 16.3% (95% CI 9.5-26.6%) for Biankouma, Ouaninou and Touba, respectively. Female and male participants were at a similar risk of infection (29.0% vs. 26.0%, odds ratio [OR]: 1.18, 95% CI 0.92-1.50). Children aged 9-14 years showed a higher prevalence than their younger counterparts aged 5-8 years (34.5% vs. 22.7%, OR: 1.80, 95% CI 1.42-2.27). High infection prevalence was observed in villages where children were washing clothes and dishes at open surface water sites and pursued recreational activities (e.g. swimming and playing in the water). The temperature, total dissolved solids and pH of water samples showed no significant association with S. mansoni infection at the village unit.

CONCLUSIONS

Human water-related activities such as washing clothes and playing in the water are risk factors for S. mansoni transmission. Hence, preventive chemotherapy should be combined with information, education and communication to avoid or reduce the frequency of water exposure in children as part of a comprehensive package of interventions towards elimination of schistosomiasis as a public health problem.

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

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

Atomic force microscopy reveals morphological and mechanical properties of schistosoma mansoni tegument

Schistosoma mansoni, an intravascular parasitic worm and the causative agent of schistosomiasis, relies on its tegument (outer layer) for survival and host interaction. This study explored the morphology and mechanical properties of S. mansoni tegument using Atomic Force Microscopy (AFM). Notably, we employed the PeakForce Quantitative Nanomechanical Mapping (PF-QNM) mode in air, enabling simultaneous acquisition of 3D topography and mechanical property contrasts (adhesion, elastic modulus). Additionally, nanoindentation (AFM contact mode) was performed on female worm tegument for elastic modulus measurement. Both techniques revealed an elastic modulus range of fractions or units of GPa for the tegument. Interestingly, mechanical property maps, particularly adhesion contrast, displayed a recurring pattern of light and dark bands. We also measured the depth of annular furrows on the female tegument, finding an average of 128 ± 10 nm. These findings establish AFM, particularly PF-QNM, as a valuable tool to characterize S. mansoni tegument properties, offering insights for future investigations into parasite biology and its response to immunological or pharmacological challenges.

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

BACKGROUND

Schistosoma japonicum infection causes hepatic fibrosis, a primary cause of morbidity and mortality associated with the disease, and effective treatments are still lacking. Long non-coding RNAs (lncRNAs) have been implicated in the pathogenic process of various tissue fibroses. However, the role of lncRNAs in schistosomiasis hepatic fibrosis (HF) is poorly understood. Understanding the role of lncRNAs in schistosomiasis HF will enhance knowledge of disease processes and aid in the discovery of therapeutic targets and diagnostic biomarkers.

METHODS

Differentially expressed lncRNA profiles in primary hepatic stellate cells (HSCs) of mice infected with S. japonicum were identified using high-throughput lncRNA sequencing. Primary HSCs were isolated from infected mice using collagenase digestion and density-gradient centrifugation, cultured in DMEM with 10% fetal bovine serum. Dual-luciferase reporter assays, nuclear cytoplasm fractionation and RIP assays were employed to assess the relationship between Malat1 and miRNA-96. Malat1 lentivirus and ASO-Malat1 were constructed for forced expression and downregulated expression of Malat1. The Malat1-KO mouse was constructed by CRISPR/Cas9 technology. Pathological features of the liver were evaluated by hematoxylin-eosin (HE), Masson's trichrome staining and immunohistochemistry (IHC). The expression levels of fibrosis-related genes were determined by quantitative real-time PCR (qRT-PCR) and Western blot.

RESULTS

A total of 1561 differentially expressed lncRNAs were identified between infected and uninfected primary HSCs. Among the top altered lncRNAs, the downregulated Malat1 was observed in infected HSCs and verified by qPCR. Treatment of infected mice with praziquantel (PZQ) significantly increased the Malat1 expression. Elevated Malat1 expression in infected primary HSC reduced the expressions of profibrogenic genes, whereas Malat1 knockdown had the opposite effect. Moreover, Malat1 was found to interact with miR-96, a profibrotic miRNA, by targeting Smad7. Forced Malat1 expression reduced miR-96 levels in infected primary HSCs, attenuating fibrogenesis and showing negative correlation between Malat1 expression and the expression levels of miR-96 and profibrogenic genes α-SMA and Col1α1. Notably, in Malat1-KO mice, knockout of Malat1 aggravates schistosomiasis HF, while restored Malat1 expression in the infected HSCs reduced the expression of profibrogenic genes.

CONCLUSIONS

We demonstrate that lncRNA is involved in regulation of schistosomiasis HF. Elevated lncRNA Malat1 expression in infected HSCs reduces fibrosis via the Malat1/miR-96/Smad7 pathway, thus providing a novel therapeutic target for schistosomiasis HF. Furthermore, Malat1 expression is sensitive to PZQ treatment, thus offering a potential biomarker for assessing the response to chemotherapy.

Immunization with the glutathione S-transferase Sj26GST with Chi-CpG NP against Schistosoma japonicum in mice

Schistosomiasis caused by Schistosoma japonicum (S. japonicum) is a major public health problem in the Philippines, China and Indonesia. In this study, the immunopotentiator CpG-ODN was encapsulated within chitosan nanoparticles (Chi NPs) to create a combination adjuvant (Chi-CpG NP). This approach was employed to enhance the immunogenicity of 26 kDa glutathione S-transferase (Sj26GST) from S. japonicum through intranasal immunization. The results demonstrated higher levels of specific anti-Sj26GST antibodies and Sj26GST-specific splenocyte proliferation compared to mice that were immunized with Sj26GST + Chi-CpG NP. Cytokine analysis of splenocytes revealed that the Sj26GST + Chi-CpG NP induced a slight Th1-biased immune response, with increased production of IFN-γ by CD4+ T-cells in the spleen. Subsequently, mice were intradermally inoculated with 1 × 107 organisms in the Coeliac cavity. The bacterial organ burden detected in the liver of immunized mice suggested that Sj26GST + Chi-CpG NP enhances protective immunity to inhibit S. japonicum colonization. Therefore, Sj26GST + Chi-CpG NP vaccination enhances Sj26GST-specific immunogenicity and provides protection against S. japonicum.

Multi-omics analyses of Bacillus amyloliquefaciens treated mice infected with Schistosoma japonicum reveal dynamics change of intestinal microbiome and its associations with host metabolism

BACKGROUND

Schistosomiasis japonica is a serious threat to human health. It causes damage to the intestine and liver. Probiotic therapy has been shown to be effective in alleviating intestinal diseases and improving host health. Previous studies have found that Bacillus amyloliquefaciens could alleviate the pathological symptoms of schistosomiasis japonica, but the regulatory mechanism of alleviating schistosomiasis japonica is still unknown.

PRINCIPAL FINDINGS

This study analyzed the dynamic changes of intestinal microbiome in mice infected with Schistosoma japonicum after the intervention of B. amyloliquefaciens and its connection to host metabolism by multi-omics sequencing technology. B. amyloliquefaciens was found to significantly regulate the homeostasis of intestinal microbiota by promoting the growth of beneficial bacteria and inhibiting potential pathogenic bacteria and protect the number of core microbes. Meanwhile, the genes related to the metabolism of glycerophospholipids and amino acid from intestinal microbiome changed significantly, and were shown to be significantly positively correlated with the associated metabolites of microbial origin. Moreover, host metabolism (lipid metabolism and steroid hormone biosynthesis) was also found to be significantly regulated.

CONCLUSIONS

The recovery of intestinal microbial homeostasis and the regulation of host metabolism revealed the potential probiotic properties of B. amyloliquefaciens, which also provided new ideas for the prevention and adjuvant treatment of schistosomiasis japonica.

Type I/II Immune Balance Contributes to the Protective Effect of AIF-1 on Hepatic Immunopathology Induced by Schistosoma japonicum in a Transgenic Mouse Model

Schistosomiasis is the second most debilitating neglected tropical disease in the world. Liver egg granuloma and fibrosis are the main damage of schistosomiasis. In this study, the role of allograft inflammatory factor-1 (AIF-1) in liver pathology and its regulation in immune responses were investigated in a transgenic mouse infected with Schistosoma japonicum. We found that AIF-1 overexpression reduced worm burden and decreased egg granuloma sizes and serum alanine aminotransferase levels, along with inhibited hepatic collagen deposition and serum hydroxyproline levels during S. japonicum infection. Moreover, AIF-1 overexpression resulted in an increased ratio of Th1/Th2, increased levels of IFN-γ and T-bet, and lower levels of GATA-3 in the spleen, accompanied by increased M1 percentages, decreased M2 percentages, and thus a higher ratio of M1/M2 in the peritoneal cavity and liver. AIF-1 induced CD68 and iNOS mRNA expression and protein levels of cytoplasmic p-P38 and nuclear NF-κB, along with enhanced levels of TNF-α and TGF-β in macrophages in vitro. Moreover, the hepatic pathology had a negative correlation with Th1/Th2 and M1/M2 ratios in the infected mice. The findings reveal that the beneficial role of AIF-1 in alleviating hepatic damage is related to restoring type I/II immune balance in S. japonicum infection.

Intra-specific variations in Schistosoma mansoni and their possible contribution to inconsistent virulence and diverse clinical outcomes

BACKGROUND

Schistosoma mansoni was introduced from Africa to the Americas during the transatlantic slave trade and remains a major public health problem in parts of South America and the Caribbean. This study presents a comprehensive comparative analysis of three S. mansoni strains with different geographical origins-from Liberia, Belo Horizonte and Puerto Rico. We demonstrated significant variation in virulence and host-parasite interactions.

METHODS

We investigated the phenotypic characteristics of the parasite and its eggs, as well as the immunopathologic effects on laboratory mouse organ systems.

RESULTS

Our results show significant differences in worm morphology, worm burden, egg size, and pathologic organ changes between these strains. The Puerto Rican strain showed the highest virulence, as evidenced by marked liver and spleen changes and advanced liver fibrosis indicated by increased collagen content. In contrast, the strains from Liberia and Belo Horizonte had a less pathogenic profile with less liver fibrosis. We found further variations in granuloma formation, cytokine expression and T-cell dynamics, indicating different immune responses.

CONCLUSION

Our study emphasizes the importance of considering intra-specific variations of S. mansoni for the development of targeted therapies and public health strategies. The different virulence patterns, host immune responses and organ pathologies observed in these strains provide important insights for future research and could inform region-specific interventions for schistosomiasis control.

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

BACKGROUND

In areas of low disease endemicity, highly sensitive diagnostic tools to identify, diagnose, and monitor intestinal schistosomiasis transmission are needed to reliably measure the burden and risk of infection. Here, we used highly sensitive molecular diagnostic methods to investigate Schistosoma mansoni prevalence and transmission along the southern shoreline of Lake Malawi, five years post-disease outbreak.

METHODOLOGY AND PRINCIPAL FINDINGS

Faecal and urine samples were provided by school-aged children situated along the southern shoreline of Lake Malawi. Kato-Katz faecal-egg microscopy and point-of-care circulating cathodic antigen (POC-CCA) rapid diagnostic tests were then performed to diagnose infection with S. mansoni. Urine-egg microscopy was also used to diagnose infection with Schistosoma haematobium. In addition, Schistosoma miracidia were isolated from faecal material using a standard miracidium hatching technique. A two-step real-time PCR approach was then used to diagnose infection with S. mansoni using DNA isolated from faecal samples. Furthermore, isolated miracidia were genotyped to species level through PCR and Sanger sequencing. Phylogenetic analyses were then carried out to identify which previously defined S. mansoni cox1 lineage group S. mansoni miracidia were most closely related to. The measured prevalence of S. mansoni infection varied considerably depending on which diagnostic assay was used. When compared to real-time PCR, faecal-egg microscopy had a sensitivity of 9% and a specificity of 100%. When POC-CCA 'trace' results were considered positive, POC-CCA had a sensitivity of 73% and a specificity of 81% when compared to real-time PCR. However, when considered negative, POC-CCA sensitivity was reduced to 56%, whereas specificity was increased to 90%. In addition, a high degree of S. haematobium DNA was detected in DNA isolated from faecal samples and motile S. haematobium miracidia were recovered from faecal samples. Schistosoma mansoni miracidia were closely related to two independent cox1 lineage groups, suggesting multiple recent introduction and colonisation events originating from surrounding east African countries.

CONCLUSIONS AND SIGNIFICANCE

Intestinal schistosomiasis is now highly prevalent along the southern shoreline of Lake Malawi just five years post-disease outbreak. In addition, a high prevalence of urogenital schistosomiasis persists. The revision of ongoing schistosomiasis control programmes in this area is therefore recommended. Our study also highlights the need for reliable diagnostic assays capable of distinguishing between Schistosoma species in multispecies co-endemic areas.

Assessment of urine metabolite biomarkers for the detection of S. haematobium infection in pre-school aged children in a rural community in Zimbabwe

BACKGROUND

Early diagnosis of urogenital schistosomiasis is key to its control and elimination. The current gold standard microscopic examination techniques lack sensitivity in detecting light Schistosomiasis infections in pre-school aged children thus it is urgent to develop diagnostic tools that may be integrated into control programs. In this study, we evaluated the diagnostic performance of urine metabolite biomarkers using a chemical reagent strip in the detection of S. haematobium infection in pre-school aged children.

METHODS

A case-control study was conducted involving 82 pre-school aged children that were age and sex matched. Urine samples were collected for 3 consecutive days and were evaluated using urine filtration gold techniques as the gold standard method. The samples were simultaneously measured for metabolite biomarkers specifically haematuria, proteins, ketones, nitrites, glucose, bilirubin and urobilinogen using chemical reagent strips. Pearson correlation test was used to measure the relationship between S. haematobium infection and the urine metabolite biomarkers.

RESULTS

The diagnostic performance of urine biomarkers were correlated with the microscopic examination urine filtration technique. Haematuria (r = 0.592, p = 0.0001) and proteinuria (r = 0.448, p = 0.0001) were correlated to S. haematobium infection. Negative correlations with p > 0.05 were recorded for ketones and urobilinogen. Highest sensitivity was 65.9 % (CI, 49.4 - 79.9) for haematuria whilst protein (albumin) biomarker had a lower specificity value of 43.9 % (28.5 - 60.3). Inversely, highest sensitivity was 87.8 % (73.8 - 95.9) for proteinuria whilst haematuria had a lower sensitivity value of 82.9 % (67.9 - 92.8). The positive predictive values ranged from 57.7 % (41.6 - 72.2) to 79.4 % (65.5 - 88.7) whereas negative predictive values ranged from 70.8 % (60.8 - 79.2) to 52.0 % (48.7 - 55.3). With respect to diagnostic efficiency, haematuria had a fair diagnostic performance with an area under the curve of 0.76 followed by proteinuria with proteinuria whilst the remaining metabolites fail discriminating ability with an area under the curve of <0.5.

CONCLUSION

Although haematuria and protein biomarkers in urine are moderately sensitive and specific, they are important morbidity indicators of urogenital schistosomiasis in pre-school aged that may be utilised during screening in schistosomiasis control programs. We recommend comprehensive analysis of biomarkers using metabolomics techniques to identify novel urine biomarkers.

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

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

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.

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

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

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.

Prevalence and correlations of schistosomiasis mansoni and schistosomiasis haematobium among humans and intermediate snail hosts: a systematic review and meta-analysis

BACKGROUND

The control of schistosomiasis is particularly difficult in sub-Saharan Africa, which currently harbours 95% of this disease. The target population for preventive chemotherapy (PC) is expanded to all age group at risk of infection, thus increasing the demands of praziquantel (PZQ) tablets according to the new released guideline by World Health Organization. Due to the gap between available PZQ for PC and requirements, alternative approaches to assess endemicity of schistosomiasis in a community, are urgently needed for more quick and precise methods. We aimed to find out to which degree the infection status of snails can be used to guide chemotherapy against schistosomiasis.

METHODS

We searched literature published from January 1991 to December 2022, that reported on the prevalence rates of Schistosoma mansoni, S. haematobium in the intermediate snails Biomphalaria spp. and Bulinus spp., respectively, and in humans. A random effect model for meta-analyses was used to calculate the pooled prevalence estimate (PPE), with heterogeneity assessed using I-squared statistic (I2), with correlation and regression analysis for the exploration of the relationship between human S. mansoni and S. haematobium infections and that in their specific intermediate hosts.

RESULTS

Forty-seven publications comprising 59 field investigations were included. The pooled PPE of schistosomiasis, schistosomiasis mansoni and schistosomiasis haematobium in humans were 27.5% [95% confidence interval (CI): 24.0-31.1%], 25.6% (95% CI: 19.9-31.3%), and 28.8% (95% CI: 23.4-34.3%), respectively. The snails showed an overall infection rate of 8.6% (95% CI: 7.7-9.4%), with 12.1% (95% CI: 9.9-14.2%) in the Biomphalaria spp. snails and 6.9% (95% CI: 5.7-8.1%) in the Bulinus spp. snails. The correlation coefficient was 0.3 (95% CI: 0.01-0.5%, P < 0.05) indicating that the two variables, i.e. all intermediate host snails on the one hand and the human host on the other, were positively correlated.

CONCLUSIONS

The prevalence rate of S. mansoni and S. haematobium is still high in endemic areas. Given the significant, positive correlation between the prevalence of schistosomes in humans and the intermediate snail hosts, more attention should be paid to programme integration of snail surveillance in future.

Schistosoma excretory/secretory products: an untapped library of tolerogenic immunotherapeutics against food allergy

Food allergy (FA) is considered the 'second wave' of the allergy epidemic in developed countries after asthma and allergic rhinitis with a steadily growing burden of 40%. The absence of early childhood pathogen stimulation embodied by the hygiene hypothesis is one explanation, and in particular, the eradication of parasitic helminths could be at play. Infections with parasites Schistosoma spp. have been found to have a negative correlation with allergic diseases. Schistosomes induce regulatory responses to evade immune detection and ensure their long-term survival. This is achieved via excretory/secretory (E/S) products, consisting of proteins, lipids, metabolites, nucleic acids and extracellular vesicles, representing an untapped therapeutic avenue for the treatment of FA without the unpleasant side-effects and risks associated with live infection. Schistosome-derived immunotherapeutic development is in its infancy and novel discoveries are heavily technology dependent; thus, it is essential to better understand how newly identified molecules interact with host immune systems to ensure safety and successful translation. This review will outline the identified Schistosoma-derived E/S products at all life cycle stages and discuss known mechanisms of action and their ability to suppress FA.

Total flavonoids of litchi Seed alleviates schistosomiasis liver fibrosis in mice by suppressing hepatic stellate cells activation and modulating the gut microbiomes

Infection with Schistosoma japonicum (S. japonicum) is an important zoonotic parasitic disease that causes liver fibrosis in both human and domestic animals. The activation of hepatic stellate cells (HSCs) is a crucial phase in the development of liver fibrosis, and inhibiting their activation can alleviate this progression. Total flavonoids of litchi seed (TFL) is a naturally extracted drug, and modern pharmacological studies have shown its anti-fibrotic and liver-protective effects. However, the role of TFL in schistosomiasis liver fibrosis is still unclear. This study investigated the therapeutic effects of TFL on liver fibrosis in S. japonicum infected mice and explored its potential mechanisms. Animal study results showed that TFL significantly reduced the levels of Interleukin-1β (IL-1β), Tumor Necrosis Factor-α (TNF-α), Interleukin-4 (IL-4), and Interleukin-6 (IL-6) in the serum of S. japonicum infected mice. TFL reduced the spleen index of mice and markedly improved the pathological changes in liver tissues induced by S. japonicum infection, decreasing the expression of alpha-smooth muscle actin (α-SMA), Collagen I and Collagen III protein in liver tissues. In vitro studies indicated that TFL also inhibited the activation of HCSs induced by Transforming Growth Factor-β1 (TGF-β1) and reduced the levels of α-SMA. Gut microbes metagenomics study revealed that the composition, abundance, and functions of the mice gut microbiomes changed significantly after S. japonicum infection, and TLF treatment reversed these changes. Therefore, our study indicated that TFL alleviated granulomatous lesions and improved S. japonicum induced liver fibrosis in mice by inhibiting the activation of HSCs and by improving the gut microbiomes.

Emerging role of liver-bone axis in osteoporosis

Background

Increasing attention to liver-bone crosstalk has spurred interest in targeted interventions for various forms of osteoporosis. Liver injury induced by different liver diseases can cause an imbalance in bone metabolism, indicating a novel regulatory paradigm between the liver and bone. However, the role of the liver-bone axis in both primary and secondary osteoporosis remains inadequately elucidated. Therefore, exploring the exact regulatory mechanisms of the liver-bone axis may offer innovative clinical approaches for treating diseases associated with the liver and bone.

Methods

Here, we summarize the latest research on the liver-bone axis by searching the PubMed and Web of Science databases and discuss the possible mechanism of the liver-bone axis in different types of osteoporosis. The literature directly reporting the regulatory role of the liver-bone axis in different types of osteoporosis from the PubMed and Web of Science databases has been included in the discussion of this review (including but not limited to the definition of the liver-bone axis, clinical studies, and basic research). In addition, articles discussing changes in bone metabolism caused by different etiologies of liver injury have also been included in the discussion of this review (including but not limited to clinical studies and basic research).

Results

Several endocrine factors (IGF-1, FGF21, hepcidin, vitamin D, osteocalcin, OPN, LCAT, Fetuin-A, PGs, BMP2/9, IL-1/6/17, and TNF-α) and key genes (SIRT2, ABCB4, ALDH2, TFR2, SPTBN1, ZNF687 and SREBP2) might be involved in the regulation of the liver-bone axis. In addition to the classic metabolic pathways involved in inflammation and oxidative stress, iron metabolism, cholesterol metabolism, lipid metabolism and immunometabolism mediated by the liver-bone axis require more research to elucidate the regulatory mechanisms involved in osteoporosis.

Conclusion

During primary and secondary osteoporosis, the liver-bone axis is responsible for liver and bone homeostasis via several hepatokines and osteokines as well as biochemical signaling. Combining multiomics technology and data mining technology could further advance our understanding of the liver-bone axis, providing new clinical strategies for managing liver and bone-related diseases.The translational potential of this article is as follows: Abnormal metabolism in the liver could seriously affect the metabolic imbalance of bone. This review summarizes the indispensable role of several endocrine factors and biochemical signaling pathways involved in the liver-bone axis and emphasizes the important role of liver metabolic homeostasis in the pathogenesis of osteoporosis, which provides novel potential directions for the prevention, diagnosis, and treatment of liver and bone-related diseases.

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

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

Detection of male genital schistosomiasis (MGS) associated with human, zoonotic and hybrid schistosomes in Southern Malawi

BACKGROUND

Male Genital Schistosomiasis (MGS) remains an often-overlooked chronic sequela of urogenital schistosomiasis in endemic areas of sub-Saharan Africa. As part of a 2-year longitudinal study on Hybridization of UroGenital Schistosomiasis (HUGS) in Malawi, a MGS sub-study was conducted to assess whether hybrid schistosomes were incriminated.

METHODS

During recruitment, demographic, health and socio-economic data were collected through individual questionnaire interviews in Mthawira community from Nsanje District along Shire River and Samama community from Mangochi District along Lake Malawi shoreline. Urine and semen samples were collected and analysed to determine the identity of schistosome infection. Urine filtration and microscopy, direct microscopy of semen and its sediments (after centrifugation) were performed. Thereafter, the sediments were examined by molecular DNA analysis with a novel two-tube real-time PCR assay. The participants were also screened for Human papilloma virus (HPV) and other sexually transmitted infections (STIs).

RESULTS

Twenty-two men were recruited for the sub-study, 8 in Nsanje District and 14 in Mangochi District, with a median age of 22.0 years. By microscopy, ten (45.7%) participants had Schistosoma ova in their urine, 11 (50.0%) in semen while 16 (72.7%) were positive by real-time PCR. One participant had both S. haematobium and S. mattheei ova in his semen, three showed symptoms, and one had a mixed infection of S. mansoni and possible S. haematobium-S. mattheei hybrid. Twelve men had detectable high-risk HPV serotypes 16, 18 and others while six had Trichomonas vaginalis and other STIs.

CONCLUSION

Zoonotic and hybrid schistosomes can cause MGS similar to human schistosomes, which can be co-infected with HPV and STIs, thereby posing a new challenge in diagnosis, management and control measures in resource poor settings. Increased awareness of these infections among local communities and primary healthcare workers and improvement of disease management are needed and advocated.

EDBD-3,6-Epidioxy-1,10-Bisaboladiene-An Endoperoxide Sesquiterpene Obtained from Drimys brasiliensis (Winteraceae) Exhibited Potent Preclinical Efficacy against Schistosoma mansoni Infection

Schistosomiasis, a neglected tropical disease impacting over 250 million individuals globally, remains a major public health challenge due to its prevalence and significant impact on affected communities. Praziquantel, the sole available treatment, highlights the urgency of the need for novel anthelmintic agents to achieve the World Health Organization (WHO) goal of schistosomiasis elimination. Previous studies reported the promising antiparasitic activity of different terpenoids against Schistosoma mansoni Sambon (Diplostomida: Schistosomatidae). In the present work, the hexane extract from branches of Drimys brasiliensis afforded a diastereomeric mixture of endoperoxide sesquiterpenes, including 3,6-epidioxy-bisabola-1,10-diene (EDBD). This compound was evaluated in vitro and in vivo against S. mansoni. EDBD exhibited a significant reduction in S. mansoni viability in vitro, with an effective concentration (EC50) value of 4.1 µM. Additionally, EDBD demonstrated no toxicity to mammalian cells. In silico analysis predicted good drug-likeness properties, adhering to pharmaceutical industry standards, including favorable ADME profiles. Furthermore, oral treatment of S. mansoni-infected mice with EDBD (400 mg/kg) resulted in a remarkable egg burden reduction (98% and 99% in tissues and feces, respectively) surpassing praziquantel's efficacy. These findings suggest the promising potential of EDBD as a lead molecule for developing a novel schistosomiasis treatment.

Exploring urinary proteomics and peptidomics biomarkers for the diagnosis of mekong schistosomiasis

Schistosomiasis caused by Schistosoma mekongi is one of the causative agents of human blood fluke infection in the lower Mekong River. Traditionally, the detection of egg morphology in stool samples has served as the prevailing method for diagnosing Schistosoma infection. Nonetheless, this approach exhibits low sensitivity, particularly in early infection detection. Urine has been extensively studied as a noninvasive clinical sample for diagnosing infectious diseases. Despite this, urine proteomic analysis of S. mekongi infection has been less investigated. This study aimed to characterize proteins and peptides present in mouse urine infected with S. mekongi both before infection and at intervals of 1, 2, 4, and 8 weeks post-infection using mass spectrometry-based proteomics. Proteomics analysis revealed 13 up- and only one down-regulated mouse protein consistently found across all time points. Additionally, two S. mekongi uncharacterized proteins were detected throughout the infection period. Using a peptidomics approach, we consistently identified two peptide sequences corresponding to S. mekongi collagen alpha-1(V) in mouse urine across all time points. These findings highlight the potential of these unique proteins, particularly the S. mekongi uncharacterized proteins and collagen alpha-1(V), as potential biomarkers for early detection of S. mekongi infection. Such insights could significantly advance diagnostic strategies for human Mekong schistosomiasis.