Search Results (247)

Schistosoma mansoni infection is associated with hepatic inflammation and fibrosis, but its systemic metabolic effects remain poorly understood. This study aimed to investigate changes in the serum lipidomic profile associated with S. mansoni infection and parasite load in individuals from an endemic area. This cross-sectional analysis was nested within a longitudinal cohort study conducted in northeastern Brazil. Parasitological diagnosis and quantification were performed using the Kato–Katz technique. A total of 45 individuals were selected and divided into three groups: high parasite load (HL), low parasite load (LL), and uninfected controls (NegE). Serum samples were analyzed using mass-spectrometry-based lipidomics. The most abundant lipid subclasses across all groups were phosphatidylcholines (PC), triacylglycerols (TAG), and phosphatidylethanolamines (PE). However, individuals in the HL group exhibited distinct lipidomic profiles, with increased levels of specific phosphatidylinositols (PI) and reduced levels of certain TAG species compared to the NegE group. These changes may reflect host–parasite interactions and immune–metabolic alterations driven by intense infection. Our findings suggest that S. mansoni infection, particularly at higher parasite burdens, can influence the host’s serum lipid profile and may contribute to metabolic disturbances in endemic populations. Full article

Neglected diseases significantly impact the world, and there is a lack of effective treatments, requiring therapeutic alternatives. Thus, the study of the phytochemical and schistosomicidal activity evaluation of Copaifera oblongifolia leaves’ crude extract was conducted. The quercitrin (1) and afzelin (2) were isolated from the crude extract. In the in vitro schistosomicidal activity test, the isolated compounds demonstrated promising results, with 75% mortality at a concentration of 12.5 µM after 72 h. Molecular docking calculations indicated that compounds 1 and 2 could potentially interact with the amino acids of the FAD binding site in the TGR enzyme, a crucial enzyme for the survival of Schistosoma mansoni. These interactions could have binding energies comparable to praziquantel, a preferred drug for treating schistosomiasis. Therefore, in silico and in vitro investigations are crucial for developing new studies that can reveal the antiparasitic potential of compounds of plant origin. Full article

Background: Dyslipidemia and schistosomiasis are major public health challenges, particularly in endemic regions where their coexistence may influence host metabolism and immune responses. This study aimed to evaluate visceral adipose tissue (AT) remodeling in a murine model of acute Schistosoma mansoni infection combined with diet-induced dyslipidemia. Methodology: Female Swiss Webster mice were fed either a standard or high-fat diet (HFD) for 29 weeks and infected with S. mansoni at week 20. Nine weeks after infection, biochemical, morphometric, histopathological, and immunological analyses were performed. Results: The HFD promoted weight gain and dyslipidemia, while S. mansoni infection alone did not alter lipid profiles but partially mitigated the metabolic effects of the HFD. Morphometric analysis revealed adipocyte hypertrophy and reduced cell number in HFD-fed animals. In HFD-fed infected mice, infection partially reversed hypertrophy, suggesting a modulatory effect on AT remodeling. Histopathological examinations showed that while a HFD induced mild inflammation, infection led to intense leukocyte infiltration, hyperemia, and plasma cell degeneration. Peritoneal lavage confirmed a proinflammatory immune profile. Conclusions: These findings indicate that the interaction between a HFD and S. mansoni infection exacerbates adipose tissue inflammation and metabolic alterations, highlighting the complex interplay between parasitic infection, diet, and immune-metabolic regulation. Full article

Urogenital schistosomiasis, caused by Schistosoma haematobium and transmitted by Bulinus snails, affects approximately 190 million individuals globally and remains a major public health concern. Effective surveillance of snail vectors is critical for disease control, but traditional identification methods are time-intensive and require specialized expertise. Environmental DNA (eDNA) detection using qPCR has emerged as a promising alternative for large-scale vector surveillance. To prevent eDNA degradation, benzalkonium chloride (BAC) has been proposed as a preservative, though its efficacy with schistosomiasis snail vectors has not been evaluated. This study tested the impact of BAC (0.01%) on the stability of Bulinus truncatus eDNA under simulated field conditions. Water samples from aquaria with varying snail densities (0.5–30 snails/L) were stored up to 42 days with BAC. eDNA detection via qPCR and multivariable linear mixed regression analysis revealed that BAC enhanced eDNA stability. eDNA was detectable up to 42 days in samples with ≥1 snail/L and up to 35 days at 0.5 snails/L. Additionally, a positive correlation between snail density and eDNA concentration was observed. These findings support the development of robust eDNA sampling protocols for field surveillance, enabling effective monitoring in remote areas and potentially distinguishing between low- and high-risk schistosomiasis transmission zones. Full article

Schistosomiasis mansoni is a neglected tropical disease caused by the parasite Schistosoma mansoni, affecting approximately 200 million people annually. Currently, treatment relies primarily on a single drug, praziquantel (PZQ), which shows limited efficacy against the parasite’s immature forms. As a result, Thioredoxin Glutathione Reductase from S. mansoni (SmTGR) has emerged as a promising target for novel drug development. This study presents the development of integrated in silico methods to identify alkaloids from medicinal plants with potential activity against S. mansoni. Fourteen alkaloids were identified, with predicted activity ranging from 61.3 to 85.2%. Among these, lindoldhamine and daibucarboline A demonstrated, for the first time, potential SmTGR inhibition, with probabilities of 85.2% and 75.8%, respectively. These findings highlight the potential of these alkaloids as promising candidates for the development of new therapies against schistosomiasis. Full article

Schistosomiasis is a parasitic disease caused by helminth parasites of the genus Schistosoma, affecting >200 million people worldwide. Current schistosomiasis treatment relies on a single drug, praziquantel, highlighting the urgent need for new therapies. We have identified a non-neuronal tegumental acetylcholinesterase from Schistosoma mansoni (SmTAChE) as a rational and molecularly defined drug target. Molecular modeling reveals significant structural differences between SmTAChE and human AChE, suggesting the potential for identifying parasite-specific inhibitors. Here, we screened recombinant SmTAChE (rSmTAChE) against two chemical libraries: the Broad Institute Drug Repurposing Hub (5440 compounds) and the Diversity-Oriented Synthesis (DOS)-A library (3840 compounds). High-throughput screening identified 116 hits from the Repurposing Hub (2.13% hit rate) and 44 from the DOS-A (1.14% hit rate) library that inhibited rSmTAChE ≥60% at 20 µM. Dose–response assays using both rSmTAChE and recombinant human AChE (rHsAChE) revealed 19 Repurposing Hub compounds (IC₅₀: 0.4–24 µM) and four DOS-A scaffolds (IC₅₀: 13–29 µM), with higher selectivity for rSmTAChE. Selective inhibitors such as cepharanthine, primaquine, mesalazine, and embelin emerged as promising candidates for further evaluation in schistosomiasis treatment. These 23 newly identified selective hits provide a foundation for the further development of novel anti-schistosome therapies. Full article

Schistosomiasis remains a major global public health challenge. Bulinus serves as an intermediate host for Schistosoma, including S. haematobium, S. intercalatum, and S. guineensis. Emerging evidence suggests that temperature fluctuations associated with global climate change are key factors influencing the survival and distribution of Bulinus. The ecological shifts in intermediate host snails may significantly influence schistosomiasis transmission dynamics, thereby exacerbating threats to human health. However, the physiological effects of temperature stress on the survival of B. globosus at the molecular level, including gene expression and underlying mechanisms, remain unclear. Our experimental study found that extreme temperature stress significantly reduced the survival rates of Bulinus globosus (B. globosus). De novo transcriptome sequencing revealed key genes associated with lipid metabolism, carbohydrate metabolism, homeostasis regulation, and the antioxidant system. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis identified significant enrichment of differentially expressed genes (DEGs) in heat shock protein pathways, propanoate metabolism, and N-acylethanolamine metabolism pathways. Overall, this work provides the first transcriptomic characterization of the thermal stress response in B. globosus, extending genomic resources for annotation and stress-related gene discovery. These findings establish a solid foundation for developing control strategies to mitigate climate-driven risks of schistosomiasis transmission. Full article

Background: The availability of laboratory tests to screen and diagnose migrants and travellers for neglected and tropical parasitic diseases significantly impacts individual and public health. Italian scientific societies for parasitology, tropical diseases, and global health developed a survey to assess number and geographical localisation of laboratories able to carry out adequate diagnostics. Methods: An open-ended and multiple-choice questionnaire was constructed and sent to 752 members working in Italian microbiology laboratories via scientific societies’ mailing lists. Data concerning malaria, cystic echinococcosis, leishmaniasis, schistosomiasis, strongyloidiasis, and Chagas disease were included. Results: Members from 96 laboratories replied. At least one laboratory responded from 18 out of 20 Italian regions. Serological tests for Schistosoma spp., Strongyloides stercoralis, Trypanosoma cruzi, Echinococcus spp., and Leishmania spp. are performed in <50% of responding laboratories. Only 56.6% of labs provide all three recommended tests for malaria diagnosis in the emergency room. Direct identification methods availability varies for Schistosoma eggs (75–95.8%), S. stercoralis larvae (53.1%), trypomastigotes (59.4%), and Leishmania amastigotes (53.1%). Geographical differences (mainly northern versus southern regions) were evident. Conclusions: The survey underlines the need to improve diagnosis for neglected and tropical diseases, to define a network of reference laboratories for testing less prevalent diseases, and to share information, education, and training for both clinicians and microbiologists/parasitologists. Full article

Schistosomes are intravascular parasitic worms that cause the debilitating tropical disease schistosomiasis, affecting >200 million people worldwide. How the worms survive within the body of immunocompetent hosts for many years is unclear. Here, using chromatography and mass spectrometry, we report on the ex vivo ability of adult Schistosoma mansoni worms to modulate the levels of 27 small molecule (often immunomodulatory) metabokines in murine plasma. Schistosomes significantly alter the relative amounts of most (16) of these molecules. Three (inosine, genistein, and glucose) are significantly decreased in the presence of the parasites. While levels of several immunomodulatory metabolites from the kynurenine pathway (kynurenine, kynurenic acid, and xanthurenic acid) remain unchanged, levels of anthranilate (an endogenous regulator of innate immunity) are significantly increased. Of particular interest are increases in levels of metabolites that are known to skew immune responses in a manner that is seen following natural schistosome infection, such as by promoting Th2 immunity (succinate), Treg generation (lactate) and M2 macrophage polarization (lactate and succinate). In addition, significant increases are also observed for 2-hydroxyglutarate, adenine, hypoxanthine, xanthine, myoinositol, betaine and N-acetylglucosamine. Each of these compounds can have immunosuppressive effects that could impact host immunological status and contribute to schistosome survival. Full article

Schistosomiasis, a neglected tropical disease caused by parasitic worms of the genus Schistosoma and transmitted through freshwater snails, affects over 200 million people worldwide. Climate change, through rising temperatures, altered rainfall patterns, and extreme weather events, is influencing the distribution and transmission dynamics of schistosomiasis. This scoping review examines the impact of climate change on schistosomiasis transmission and its implications for disease control. This review aims to synthesize current knowledge on the influence of climate variables (temperature, rainfall, water bodies) on snail populations, transmission dynamics, and the shifting geographic range of schistosomiasis. It also explores the potential effects of climate adaptation policies on disease control. The review follows the Arksey and O’Malley framework and PRISMA-ScR guidelines, including studies published from 2000 to 2024. Eligible studies were selected based on empirical data on climate change, schistosomiasis transmission, and snail dynamics. A two-stage study selection process was followed: title/abstract screening and full-text review. Data were extracted on environmental factors, snail population dynamics, transmission patterns, and climate adaptation strategies. Climate change is expected to increase schistosomiasis transmission in endemic regions like Sub-Saharan Africa, Southeast Asia, and South America, while some areas, such as parts of West Africa, may see reduced risk. Emerging hotspots were identified in regions not currently endemic. Climate adaptation policies, such as improved water management and early warning systems, were found effective in reducing transmission. Integrating climate adaptation strategies into schistosomiasis control programs is critical to mitigating the disease’s spread, particularly in emerging hotspots and shifting endemic areas. Full article

Background: Madagascar is one of the lowest-income countries in Africa, and it has a poorly developed healthcare system. Malagasy women face limited access to sexual and reproductive health services, which is a serious risk factor facilitating the spread of sexually transmitted infections (STIs). The aim of the present study was to assess the prevalence of STIs (Trichomonas vaginalis, Neisseria gonorrhoeae, Treponema pallidum, and HIV-1/HIV-2) and urogenital schistosomiasis, as well as to evaluate hematological parameters and nutritional status, in a group of women from northern Madagascar. Methods: The study was conducted in April 2024 at the Clinique Médicale Beyzym in Manerinerina, Ambatoboeny District. Samples, which included overnight urine, venous blood, and vaginal swabs, were collected from 159 women aged 15–80 years. The urine samples were examined for the presence of Schistosoma haematobium eggs by light microscopy, the vaginal swabs were tested for the presence of Trichomonas vaginalis and Neisseria gonorrhoeae infections (by light microscopy), and venous blood samples were collected into VACUTAINER SEC collection tubes without anticoagulant and were tested for HIV-1/HIV-2 and Treponema pallidum infections using test cassettes. Results: The prevalence of STIs in the study group was found to be 31.5%, while S. haematobium infections were found in 17.6% of the tested women. Cases of gonorrhea (20.1%), trichomoniasis (8.8%), syphilis (7.6%), and one case of HIV infection were identified. Conclusions: The study found a high prevalence of STIs and S. haematobium cases in Tsimihety women. In order to improve the quality of healthcare in Madagascar, it is necessary to improve accessibility to maternal, sexual, and reproductive health services. Full article

Introduction: One of the global strategies for the elimination of schistosomiasis is by Mass Drug Administration (MDA) of a single oral dose of praziquantel (40 mg/kg) without a prior individual diagnosis, with a target of >75% treatment coverage among school-aged children. This study was conducted to determine the endemicity of schistosomiasis among school-aged children and adults in Abuja, Nigeria. Methods: A total of 1370 participants were recruited, which consisted of 667 (48.67%) males and 703 (51.31%) females. Urine and stool specimens were collected from each participant and analyzed using standard procedures. Results: The overall prevalence of schistosomiasis was 27.5% in this study with Abuja Municipal having the highest prevalence of 49%, while the least (6.1%) was reported in Bwari LAC. The prevalence of schistosomiasis significantly differs (p < 0.05) between the area councils. The location of communities significantly affected the prevalence of schistosomiasis in Abaji, AMAC, and Gwagwalada LACs (p < 0.005). The Schistosoma recovered in this study were S. haematobium and S. mansoni. The prevalence of schistosomiasis increased from the baseline of 21.1% to 49% in Gwagwalada LAC. Gender significantly affected the prevalence of schistosomiasis as more males were infected (33.1%) than their female counterparts (22.2%) (p < 0.05). The prevalence of schistosomiasis was 31% and 23.9% among SAC and adults, respectively. The participants’ activities in the river significantly affected the prevalence of schistosomiasis in this study (p < 0.05). Conclusions: The clamour for urgent government and non-government intervention through alternate sources of water like boreholes or pipe-borne water, as well as implementing a behavioural change campaign across the communities to prevent the recurrence, are advocated. Full article

Background: Urogenital schistosomiasis is endemic in Gabon. Our study aimed to detect the prevalence of urinary schistosomiasis and to evaluate the diagnostic performance of the qPCR technique compared to microscopy for the detection of Schistosoma haematobium at the community level in a semi-rural area. Method: A cross-sectional survey was carried out. Urine samples were examined using Urine TICK test strips, a filtration technique, and qPCR. Schistosoma haematobium was detected by targeting the Dra1 gene. Results: The prevalence of urogenital schistosomiasis was determined and the performance of real-time PCR and urine strips was compared with that of urinary filtration. A total of 281 participants were enrolled in the study. The prevalence of urogenital schistosomiasis was increased slightly with the molecular technique (40.9%) compared to microscopy (36.7%), and the hematuria rate with Urine STICK was 33.5%. SAC (5–14 years old), Pre-SAC (>5 years old), and adolescents (15–17 years old) were the most affected group according to, respectively, whatever method was used. qPCR showed good agreement with microscopy, as well as excellent sensitivity (99.03%) and specificity (93.3). There was a good correlation between the number of eggs per 10 mL and the cycle threshold range. Conclusion: These results show the importance of using a combination of diagnostic tools in the surveillance of schistosomiasis, particularly in preschool children, adolescents, women of childbearing age, and chronic and asymptomatic cases. Full article

Schistosoma japonicum eggs in the host liver form granuloma and liver fibrosis and then lead to portal hypertension and cirrhosis, seriously threatening human health. Natural killer (NK) cells can kill activated hepatic stellate cells (HSCs) against hepatic fibrosis. We used single-cell sequencing to screen hepatic NK cell subsets against schistosomiasis liver fibrosis. Hepatic NK cells were isolated from uninfected mice and mice infected for four and six weeks. The NK cells underwent single-cell sequencing. The markers’ expression in the NK subsets was detected through Reverse Transcription–Quantitative PCR (RT-qPCR). The proportion and granzyme B (Gzmb) expression of the total NK and Thy1⁺NK were detected. NK cells overexpressing Thy1 (Thy1-OE) were constructed, and functions were detected. The results revealed that the hepatic NK cells could be divided into mature, immature, regulatory-like, and memory-like NK cells and re-clustered into ten subsets. C3 (Cx3cr1⁺NK) and C4 (Thy1⁺NK) increased at week four post-infection, and other subsets decreased continuously. The successfully constructed Thy1-OE NK cells had significantly higher effector molecules and induced greater HSC apoptosis than the control NK cells. It revealed a pattern of hepatic NK cells in a mouse model of schistosomiasis. The Thy1⁺NK cells could be used as target cells against hepatic fibrosis. Full article

Identification of individuals of Biomphalaria is a challenging task, since morphological aspects alone are not sufficient to distinguish between species, which share many similar characteristics. However, the accurate identification of species of Biomphalaria is crucial for monitoring of schistosomiasis, since these species are intermediate hosts of the parasite Schistosoma mansoni, which causes the disease, which is prevalent in the north region of Brazil. In this context, the objective of this study was to identify specimens of Biomphalaria that occur in Mapiri Lake, in the lower Amazon region, in Santarém, Pará, Brazil. An integrated approach was used for identification of specimens of Biomphalaria, which included embryological and morphological analyses (comparison of diagnostic characteristics between species of the genus), as well as molecular assays using the Sanger sequencing method with dideoxy chain termination, as a method to reinforce the precision of species identification. The results establish the first record of B. amazonica in the state of Pará. This species has a development cycle consistent with that observed for other species of the genus Biomphalaria but possesses morphological characteristics that make accurate identification at the species level difficult, which reinforces the need for the molecular analyses. The first record of B. amazonica in the state of Pará in this study enlarges the distribution area of this species in Brazil, which demonstrates the importance of research focused on the identification of species of Amazonian mollusks as an auxiliary tool that can be used to combat schistosomiasis. Full article