Search Results (97)

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

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

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

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: 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

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

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

Schistosomiasis is a parasitic disease that is considered a major threat to public health in Madagascar. The condition is endemic in more than 90% of the country’s districts. It is estimated that as much as 52% of the country’s general population is infected with Schistosoma spp. trematodes. The aim of the present study was to assess the prevalence values of Schistosoma haematobium infections in a population of children living in northern Madagascar and to determine the impact of trematode infections on the hematological profiles of the children included in the study. This screening study was conducted in 2024, and it involved a group of 170 children aged 0–17 years. The participants were required to provide urine samples for microscopic and molecular examination. The urine samples were preserved on Whatman 903 protein sever cards using the dried urine spot (DUS) sampling technique and then were transported from Madagascar to a molecular laboratory in Poland, where the samples were tested for the presence of S. haematobium. The present study found that the incidence of S. haematobium infections in the study group consisting of 170 children was as high as 67.6%. The authors observed a reduction in mean hemoglobin (Hb) and mean corpuscular hemoglobin concentration (MCHC) values in the infected children. In spite of continuous efforts to prevent the transmission of schistosomiasis in endemic countries (WHO-recommended mass drug administration campaigns), the incidence of S. haematobium infections was found to be exceptionally high among the study participants. S. haematobium infections present with a characteristic hematological picture showing signs of increased immune response and anemia. The DUS technique has been successfully used for the molecular diagnosis of S. haematobium. This method opens up possibilities for more effective and less expensive sample collection. Full article

This quasi-experimental trial examined the relationship between Schistosoma haematobium infection and nutritional status, and the impact of single dose praziquantel (PZQ) therapy on undernutrition. A total of 353 children were examined, 112 of which were infected with S. haematobium and treated with PZQ. Children’s heights, weights, and mid-upper arm circumferences (MUAC) were measured at baseline and one month post-treatment. Infected children had significantly smaller mean BMI-for-age z-scores (BAZ) (−1.16 vs. 0.11, p < 0.01) and weight-for-age z-scores (WAZ) (−0.61 vs. −0.31, p = 0.03) than the uninfected ones at baseline. S. haematobium infection was associated with underweight (adjusted OR: 1.76, 95% CI: 1.63–1.90). One month after treatment, BAZ, WAZ, height for age z-scores (HAZ), and MUAC scores were comparable between treated and control children. However, there was a significant decrease in the prevalence of underweight among treated children, while no significant change was observed in the control group one month post-treatment. In conclusion, children infected with S. haematobium are likely to suffer from undernutrition; however, single dose PZQ therapy may not improve their nutritional status within one month of treatment. Future studies could have longer follow-up periods to better estimate the drug’s effect on nutrition. Full article

Background: Chronic schistosomiasis can lead to significant morbidity. Serology is highly sensitive; however, its role in assessing treatment response is controversial. This study aimed to analyze serological values following treatment of chronic imported schistosomiasis. Methods: A retrospective observational study was performed including patients treated for chronic imported schistosomiasis from 2018 to 2022 who had at least one serological result at baseline and during follow-up. Demographic, clinical, and laboratory data were evaluated. Generalized estimating equation (GEE) models and Kaplan–Meier curves were used to analyze the evolution of serological values. Results: Of the 83 patients included, 72 (86.7%) were male, and the median age was 26 years (IQR 22–83). Most patients, 76 (91.6%), were migrants from sub-Saharan Africa. While 24 cases (28.9%) presented with urinary symptoms, the majority (59; 71.1%) were asymptomatic. Schistosoma haematobium eggs were observed in five cases (6.2%). Eosinophilia was present in 34 participants (40.9%). All patients had an initial positive Schistosoma ELISA serology, median ODI 2.3 (IQR 1.5–4.4); the indirect hemagglutination (IHA) test was positive/indeterminate in 34 cases (43.1%). Following treatment with praziquantel, serology values significantly decreased: −0.04 (IC95% −0.073, −0.0021) and −5.73 (IC95% −9.92, −1.53) units per month for ELISA and IHA, respectively. A quarter of patients (25%) had negative ELISA results 63 weeks after treatment. All symptomatic cases were clinically cured. Conclusions: Serial serological determinations could be helpful for monitoring chronic schistosomiasis in non-endemic regions. The ideal timing for these follow-up tests is yet to be determined. Further research is needed to determine the factors that influence a negative result during follow-up. Full article

Urinary schistosomiasis is caused by the blood fluke Schistosoma haematobium, which is predominantly found in Africa. The freshwater snail Bulinus globosus is its main intermediate host. The species that make up the B. globosus group are genetically complex, and their taxonomic status remains controversial. Genetic variation, heterozygosity, and DNA recombination in B. globosus were examined using the mitochondrial cytochrome c oxidase subunit 1 (COI) and the intron 3 region of the arginine kinase gene (AkInt3). A total of 81 B. globosus snails were collected from three different localities in Kwale County, Kenya. Genomic diversity, heterozygosity, DNA recombination, and haplotype network were calculated using AkInt3 sequences. Low polymorphism in the COI sequence divided B. globosus into six haplotypes (C1–C6). However, AkInt3 sequencing studies showed high polymorphisms, classifying 81 B. globosus snails into 44 haplotypes (H1–H44). These haplotypes were separated into three haplogroups (I–III). AkInt3 sequence heterozygosity was also found. DNA recombination haplotypes between haplogroups were commonly found in heterozygous samples. AkInt3 sequence studies showed high levels of genetic polymorphism and heterozygosity, supporting its use as a genetic marker for elucidating the population genetics of B. globosus. Furthermore, our study showed that B. globosus populations in Kenya form a “species complex”. Full article

Female Genital Schistosomiasis (FGS) is caused by Schistosoma haematobium, which causes chronic gynecological conditions that lead to substantial morbidity and infertility. This study’s objective is to determine the prevalence and burden of FGS based on the presence of S. haematobium-specific DNA in females across age groups using our previously field-acquired filtered human urine samples from Zambia, Tanzania, and Ghana, collected over multiple years. For Ghana (2013), 39 out of 90 samples were from females, of which 31 (79.5%) were positive and 8 (20.5%) were negative. In Zambia (2016), 80 out of 133 samples were from females, of which 46 (57.5%) tested positive and 34 (42.5%) were negative. For Zambia (2017), 60 out of 110 samples were from females, of which 45 (75%) tested positive and 15 (25%) tested negative. In Tanzania (2018), 70 out of 104 samples were from females, of which 43 (61.4%) tested positive and 27 (38.6%) tested negative. FGS prevalence ranged from 57.5% (Zambia in 2016) to 79.5% (Ghana in 2013) and was found predominantly among the 11–20 years age group. The analytical outcome highlights that FGS is predominant among females in different endemic countries and in the age range of pre-teen to young adult. Full article