Search Results (223)

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

Background: Polyparasitic infections remain widespread in endemic regions, yet its contributing factors and health impact are not well understood. This study aims to estimate the prevalence and associated factors and examines the effect of polyparasitic infection on haemoglobin levels among children. Methods: A cross-sectional study was conducted in Lambaréné, Gabon, among children aged 2–17 years from November 2019 to December 2020. Haemoglobin levels, environmental conditions, and sociodemographic data were collected. Stool, urine, and blood samples were analysed using light microscopy for parasite detection. Factors associated with polyparasitism were explored. Results: Out of 656 participants, 65.4% had at least one infection, with intestinal protozoa species (21.3%), Trichuris trichiura (33%), Ascaris lumbricoides (22%), Schistosoma haematobium (20%), and Plasmodium falciparum (10%) being the most common. Polyparasitic infection was identified in 26% of children, mostly as bi-infections (69.2%), and was negatively associated with haemoglobin levels (β = −0.06). Conclusions: These findings emphasise the burden of polyparasitic infections and adverse health effects in Lambaréné, Gabon. 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

Background: There is substantial evidence supporting the role of genetic alterations in chemically induced carcinogenesis. We analyzed the existing literature to gather data on genetic alterations linked to human carcinogens and their possible connection to genotoxic outcomes. The review emphasizes carcinogenic substances and occupational exposures identified as “carcinogenic to humans”. In particular, we searched for studies describing genotoxic alterations linked to agents and occupational exposures for which the International Agency for Research on Cancer has found sufficient evidence of an association with bladder cancer. Methods: The review was carried out in compliance with the PRISMA standards. A comprehensive search of the PubMed database was conducted to identify studies published through March 2024. Results: We identified 60 studies that evaluated genetic alterations for 16 carcinogenic agents and occupations (such as aluminum production, 4-aminobiphenyl, auramine production, benzidine, chlornaphazine, cyclophosphamide, firefighters, magenta production, 2-naphthylamine, opium consumption, ortho-toluidine, painters, the rubber manufacturing industry, Schistosoma haematobium infection, X-radiation, gamma-radiation) in healthy humans. Conclusions: The genotoxic effects of chemical agents in healthy individuals have been well studied and characterized. Additionally, this review presents numerous studies concerning occupational exposure but not exclusively. Genotoxicity assessments have mainly been conducted on biological materials such as blood, peripheral blood lymphocytes, urine, and buccal epithelial cells. The most frequently examined genotoxic effects were DNA damage, chromosomal abnormalities, and micronuclei. Standardized data to clearly define a dose–response relationship for predicting delayed health effects are still lacking. Full article

Coinfection with parasites and viruses can exacerbate disease transmission, outcomes and therapy. This study searched the Web of Science, PubMed, Scopus and JSTOR databases for publications on the prevalence of parasitic coinfection in people living with viruses from 1 January 2005 to 30 April 2022, and 356 studies were included and systematically reviewed. A meta-analysis was performed to assess the global prevalence of and factors potentially associated with parasitic infection (helminths and protozoa) in virus-infected people, and the infection burden was estimated. A variety of parasites (29 families, 39 genera, and 63 species) and viruses (8 kinds) were identified. The prevalence of parasitic coinfection in (all) virus-infected people was estimated to be 21.34% (95% CI 17.58–25.10, 5593 of 29,190 participants) and 34.13% (95% CI 31.32–36.94, 21,243/76,072 participants) for helminths and protozoa, respectively. Specially, in human immunodeficiency virus (HIV)-infected people, the global prevalence was 19.96% (95% CI 16.18–23.74) for helminths and 34.18% (95% CI 31.33–37.03) for protozoa, respectively. The global prevalence of protozoa was 41.79% (95% CI 15.88–67.69) in hepatitis B virus (HBV)-infected people and 17.75% (95% CI 3.54–31.95) in DENV-infected people, respectively. The global burden of parasitic infections in HIV-infected people was 7,664,640 for helminths and 13,125,120 for protozoa, respectively, and that in HBV- and dengue virus (DENV)-infected people was 137,019,428 and 629,952, respectively. The prevalence of parasitic coinfection at the family, genus, and species levels in virus- or HIV-infected people were comprehensively estimated and further analyzed by subgroups. Among the most commonly identified parasites, the five helminth genera with the highest prevalence in HIV-infected people were Schistosoma (12.46%, 95% CI 5.82–19.10), Ascaris (7.82%, 95% CI 6.15–9.49), Strongyloides (5.43%, 95% CI 4.11–6.74), Trichuris (4·82%, 95% CI 2.48–7.17) and Ancylostoma (2.79%, 95% CI 1.32–4.27), whereas the top five protozoan genera were Toxoplasma (48.85%, 95% CI 42.01–55.69), Plasmodium (34.96%, 95% CI 28.11–41.82), Cryptosporidium (14.27%, 95% CI 11.49–17.06), Entamoeba (12.33%, 95% CI 10.09–14.57) and Blastocystis (10.61%, 95% CI 6.26–14.97). The prevalence of parasitic coinfection in virus-infected people was associated with income level. The findings provide valuable global epidemiological information for informing normative guidance, improving surveillance, and developing public healthcare strategies. 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

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

Objective: Schistosoma mansoni (S. mansoni) infection is endemic in Ugandan fishing communities. We investigated its potential impact on Hepatitis B (Hep B) vaccine responses and its role in mediating the association between the gut microbiome and long-term effectiveness of the vaccine. Methods: Participants were tested for S. mansoni infections at baseline and received the Hep B vaccine at baseline, month 1, and month 6. Those with infections were treated. Stool samples were collected at baseline and analyzed using 16S rRNA sequencing. The Wilcoxon rank-sum test was used to compare alpha diversity between groups. A linear regression model was applied to estimate the association between one-year Hep B vaccine responses and the baseline gut microbiome by infection status, adjusting for age and sex. Results: A total of 107 participants were included (44 from the fishing community and 63 from the Kampala community). There was no significant difference in microbiome composition by location or infection status at baseline or discharge. In the linear regression analysis, S. mansoni infection (β = 1.24, p = 0.025) and a higher alpha diversity (β = 0.001, p = 0.07) were associated with higher Hep B vaccine responses, while older age was associated with a lower Hep B vaccine response (β = −0.06, p = 0.0013). Conclusions: S. mansoni infection status before vaccination may modify the association between the gut microbiome and Hep B vaccine response. Potential interventions could focus on infection control as well as improving microbiome richness before implementing vaccine programs in fishing communities. 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

Background: Schistosomiasis (SCH) and soil transmitted helminthiasis (STH) have been targeted for elimination as a public health problem (EPHP) within the World Health Organization (WHO)’s Roadmap for Neglected Tropical Diseases (NTDs) 2021–2030. One of the global strategies for the control and elimination of these diseases is the mass administration of praziquantel and albendazole/mebendazole without prior individual diagnosis. To measure the progress towards the 2030 target, we conducted an assessment to determine the impact of the 3–5 rounds of annual mass drug administration among school age children in Ekiti State. Such scientific insights into the impact of these treatments will facilitate improved planning and targeting of resources towards reaching the last mile. Methodology: This assessment was conducted in 16 local government areas (LGAs) of Ekiti State between October and November 2023. Samples were collected from pupils in 166 primary and junior secondary schools across 166 wards of the State. Urine and stool samples were collected from 7670 pupils of ages 5 to 14 years, following standard laboratory procedures. Urine membrane filtration techniques were used for urine preparation while the Kato–Katz technique was used for stool preparation. A novel AiDx digital microscope was used to examine the presence of any ova in the prepared specimen. Parasite ova in urine were reported as the number of ova/10 mL of urine, and were categorized as light infection (˂50 ova/10 mL of urine) or heavy infection (>50 ova/10 mL of urine) while ova of parasites in stool samples were reported as eggs per gram of stool (EPG) and categorized into light, moderate and heavy infection. Results: Overall, 0.76% (0.56–0.95) at 95% CI of the 7670 respondents were infected with Schistosomia haematobium. No Schistosoma mansoni infection was recorded in the study. Similarly, 3.9% (3.43–4.29) at 95% CI were infected with STHs. The overall prevalence of schistosomiasis had significantly reduced from 8.2% in 2008 to 0.8%, while the overall prevalence of STHs significantly reduced from 30.9% to 3.9% with Ascaris lumbricoides being the dominant species of STH. In the 16 LGAs assessed, Ekiti West had the highest S. haematobium prevalence of 4.26%. Ise/Orun and Oye ranked second and third with a prevalence of 3.48% and 2.40% respectively, while all other LGAs had <1% prevalence. The prevalence of STHs was highest in Ekiti-West with a prevalence of 10.45% while Emure and Ikole Local Governments had the lowest prevalence of 0.31% and 0.38%, respectively. There was no significant difference in the prevalence of schistosomiasis between male (0.76%) and female (0.75%) as p ≥ 0.05. Similarly, the difference in prevalence for STH among males (3.95%) was not significantly different from their female counterparts (3.77%), p ≥ 0.05. Conclusions: Based on the WHO guidelines, this study demonstrated that only three LGAs require continued MDA every 2/3 years, seven require only surveillance while six are now non-endemic for schistosomiasis. Similarly, two of the LGAs require one round of MDA yearly, eight LGAs need one round of MDA every two to three years and six LGAs are now below the treatment threshold and no longer require treatment for STH. Full article

Introduction: Freshwater snails, particularly snails from the genus Biomphalaria, play a key role in the transmission of schistosomiasis, a parasitic disease prevalent in tropical regions. Schistosomiasis poses a significant public health challenge in these regions, leading to chronic illness, reduced productivity, and impaired childhood development, particularly in communities with limited access to healthcare and sanitation. Understanding the seasonal and spatial variations in snail populations and infection rates is crucial for controlling schistosomiasis, especially in areas like Southwest Ethiopia, where the disease burden is high. Methods: This study was conducted in Mizan Aman, Southwest Ethiopia, across two seasons, dry and wet. A total of 1150 snail samples were collected from 20 freshwater sites, and their species, abundance, and infection status were assessed. Environmental parameters, including temperature, pH, salinity, and conductivity, were measured to analyze their impact on snail populations. Results: Four snail species were identified, Biomphalaria pfeifferi, Biomphalaria sudanica, Lymnaea natalensis, and Bulinus globosus, with B. pfeifferi and B. sudanica being the most prevalent. Snail abundance varied by site and season, with 598 in the dry season and 552 in the wet season. Snail abundance and species composition showed significant spatial variation, with higher counts in sites like Sasin and Agu 1, while some sites had no snails. Biomphalaria snails, particularly B. pfeifferi, are the principal intermediate host for Schistosoma mansoni. The overall prevalence of Biomphalaria snails exceeded 85% in both seasons, and their average infection rate in Mizan Aman was 13.5%. This infection rate showed a strong correlation (r = 0.733, p < 0.001) with the incidence of schistosomiasis cases in the community. Seasonal variation in environmental factors, such as temperature and pH, had no significant effect on snail abundance; however, water salinity showed to be correlated with snail abundance during the dry season. Furthermore, community-led vegetation clearance at selected sites significantly reduced snail abundance. Conclusions: This study highlights the seasonal and spatial dynamics of freshwater snails, particularly Biomphalaria species, in relation to schistosomiasis transmission in Mizan Aman, Southwest Ethiopia. The findings confirm that B. pfeifferi species is the predominant intermediate host for schistosoma in this region and that schistosomiasis infection rates among snails significantly correlate with human cases in the community. While environmental factors such as temperature and pH showed no significant influence on snail abundance, water salinity had an impact during the dry season. Additionally, community-led vegetation clearance was an effective intervention in reducing snail populations. These results emphasize the need for targeted, site-specific control measures integrating ecological and community-based interventions to sustainably reduce schistosomiasis transmission. Full article

Background/objectives: Schistosomiasis is caused by flatworms of the genus Schistosoma, for which mollusks of the genus Biomphalaria are intermediate hosts. Niclosamide (NCL) is a molluscicide recommended by the World Health Organization (WHO) for control of Biomphalaria. Although effective, it is expensive and environmentally toxic, which raises concerns regarding its widespread use. As a result, we explored new synthetic substances as alternative strategies for controlling Biomphalaria glabrata. We evaluated the molluscicidal activity of 2-(1H-py-razol-1-yl)-1,3,4-thiadiazole and 2-(4,5-dihydro-1H-pyrazol-1-yl)-1,3,4-thiadiazole derivatives against B. glabrata snails and embryos, as well as Schistosoma cercariae (infective larvae). Methods: Adult and young snails were added to 24-well plates containing 20 synthetic compounds from the PDAN series for initial screening over 96 h at a concentration of 100 ppm. Water and NCL (2 ppm) were used as the negative and positive controls, respectively. Active compounds in the adult B. glabrata assay were selected for the tests vs. embryos and cercariae. Results: In the initial screen, only PDAN 52 (63 ± 4%) and 79 (12 ± 3%) showed molluscicidal activity at a concentration of 100 ppm up to 48 h. Consequently, we selected only PDAN 52. The LC₅₀ value found in the tests on embryos after 24 h of treatment was 20 ± 2 ppm and, after 48 h, it was 4 ± 0.5 ppm. Against cercariae, we measured an LC₅₀ value of 68 ± 5 ppm after 4 h of treatment. PDAN 52 did not induce marked toxicity against a second mollusk, Physella acuta, after 48 h of exposure. Conclusions: We highlight the promising molluscicidal activity of PDAN 52 against different developmental stages of the mollusk, B. glabrata, as well the infective larvae of Schistosoma mansoni. Full article

Background/Objectives: Following previous successful Phase I clinical trials conducted in men and women in a non-endemic area for schistosomiasis in Brazil, the Sm14 vaccine was evaluated in an endemic region in Senegal. We report successful clinical trials in adults (Phase IIa) and school children (Phase IIb), respectively, of a Schistosoma mansoni 14 kDa fatty acid-binding protein (Sm14) vaccine + a glucopyranosyl lipid A (GLA-SE) adjuvant. Methods: Participants were evaluated based on clinical assessments, laboratory tests (including hematologic and biochemical analyses of renal and hepatic functions), and immunological parameters (humoral and cellular responses) up to 12 months after the first vaccination dose in the Phase IIa trial and after 120 days in the Phase IIb trial. Results: The results showed strong immunogenic responses and good tolerance in both adults and children, with no major adverse effects. Importantly, significant increases in Sm14-specific total IgG (IgG1 and IgG3) were observed as early as 30 days after the first vaccination, with high titres remaining at least 120 days afterwards. Sm14-specific total IgG serum levels were also significantly enhanced in adults and in both infected and non-infected, vaccinated children and elicited robust cytokine responses with increased TNFα, IFN-γ, and IL-2 profiles. Conclusions: Overall, the Sm14+GLA-SE vaccine is safe and highly immunogenic, with a clearly protective potential against schistosomiasis, supporting progression to the next Phase III clinical trials. Full article

This study evaluated the performance of urine reagent strips (URSs) in detecting Schistosoma haematobium infection in individual and pooled urine samples. Between June 2022 and April 2023, 2634 urine samples (10 mL each) from school-age children (5–15 years) in 15 villages across Ethiopia’s Afar, Benishangul-Gumuz, and Gambella regions were tested using urine filtration microscopy (UFM) and URSs for blood, a marker of S. haematobium eggs. Pooled samples from 5, 10, 20, and 40 individuals (one positive, others negative) were examined with both methods. UFM results were used to calculate URSs’ sensitivity, specificity, and predictive values for detecting infection. A total of 2634 children were screened for S. haematobium infection. UFM detected S. haematobium eggs in 370 samples, while URSs identified infection in 414 children. URSs showed 64% sensitivity and 92% specificity for individual samples. The positive and negative predictive values for individual samples were 57% and 94%, respectively. Sensitivity for pooled samples ranged from 47% (pools of 40) to 53% (pools of 20). In pools with one positive sample, URSs misclassified 220 (50%), 109 (49.5%), 52 (47.0%), and 28 (50.9%) pools as negative for S. haematobium eggs for pool sizes 5, 10, 20, and 40, respectively. Sensitivity for individual samples was higher in children with heavy infection (92.5%) compared to light infection (55.9%), and sensitivity in pooled samples increased with infection intensity (p < 0.001). In conclusion, URSs may misclassify S. haematobium infection in children when samples are examined individually or in pools, potentially leading to unnecessary treatment or missed cases. However, URSs shows promise as a screening tool for detecting S. haematobium infection in areas with high infection intensity. Full article