Mansoni Infection Research Articles

Teachers as multipliers of knowledge about schistosomiasis: a possible approach for health education programmes

BackgroundIn the past decade, Brazil has significantly reduced the prevalence of schistosomiasis through a combined effort of early treatment of infected people, expansion of basic sanitation infrastructure and educational measures. Despite these efforts, in some areas, prevalence of schistosomiasis exceeds 20% of the school population, who lack knowledge of the risks of the disease. Action can be taken in schools to empower this population about their health condition. This paper describes the role of the teacher as a multiplier of knowledge about schistosomiasis and proposes two different approaches to training these teachers.MethodsThis study used mixed methods to evaluate training of teachers and educational intervention with those teachers’ pupils. Two training courses, each with 40 h of face-to-face activity, were offered to 19 teachers, using two different but complementary approaches, based on theoretical references and specific educational strategies: Critical Pedagogical Approach (Training Course I, held in 2013) and Creative Play Approach (Training Course II, held in 2014).The courses included classroom activities, laboratory and field work. After the training, the teachers conducted activities on schistosomiasis with their pupils. These activities involved constructing educational materials and cultural productions. The pupils’ knowledge about the disease was evaluated before the activities and 12 months later. The teachers’ acceptance and perceptions were assessed through structured interviews and subsequent thematic analysis. The Shistosoma mansoni infection status of teachers and their students was also assessed using the Kato Katz stool test.ResultsThe parasitological study showed 31.6% of the teachers and 21.4% of the pupils to be positive for S. mansoni. The teachers’ knowledge of important aspects of schistosomiasis transmission and prevention was fragmented and incorrect prior to the training. The teachers’ knowledge changed significantly after the training and they were strongly accepting of the pedagogical methods used during the training. The level of their pupils’ knowledge about the disease had increased significantly (p < 0.05). However, pupils responded that, even after the educational activities, they still had contact with the city’s contaminated waters (p > 0.05).ConclusionsThe results of this study underline the importance of schools and teachers as partners in controlling and eliminating schistosomiasis. Teacher training on the disease significantly increases their pupils’ knowledge, reflecting empowerment with regard to local health conditions.

Association between water, sanitation, and hygiene access and the prevalence of soil-transmitted helminth and schistosome infections in Wolayita, Ethiopia

BackgroundThe Geshiyaro project is a 5-year intervention to assess the impact of community- and school-based water, sanitation, and hygiene (WaSH) interventions on reducing infection with soil-transmitted helminths (STH) and schistosome parasites in combination with deworming in Wolayita zone, Ethiopia.MethodsA population-based, cross-sectional census and parasitological mapping activity was conducted between 2018 and 2019. Individuals in the census were identified using either a registered study ID card or biometric fingerprint to enable linkage of their household WaSH data with baseline STH and schistosome prevalence for risk analysis.ResultsPrevalence of STH was 15.5% for any STH species, 9.47% for Ascaris lumbricoides, 1.78% for Trichuris trichiura, and 7.24% for hookworm. Intestinal schistosomiasis (Schistosoma mansoni) infection prevalence was 0.85% by Kato Katz, 21.6% by POC-CCA trace positive (Tr +), and 13.3% trace negative (Tr-). Microhaematuria was 2.77%, with 0.13% of people examined with S. haematobium eggs detected by urine filtration. At the household level, increased (> 30 min) time taken to collect drinking water, sharing a latrine, and lack of handwashing facilities were all associated with a greater risk of A. lumbricoides, hookworm, and S. mansoni infection. Not disposing of infant stool at the household and clothes washing/recreational freshwater contact were significantly associated with higher risk of schistosomiasis infection. Aggregating WaSH data at the community level showed odds of A. lumbricoides, hookworm, and T. trichiura infection were significantly lower as both community sanitation coverage and access to improved drinking water improved.ConclusionsThe principal finding of this study is that lack of access to WaSH, such as improved drinking water and shared toilet and hand-washing facilities, were linked to an increased risk of infection with STH and schistosome parasites. These associations are difficult to establish at an individual household level because of wide variability in access between houses but are detectable when coverage is aggregated at the community level. Maintenance of WaSH facilities as well as increased access within the whole community is important in influencing the community-wide prevalence of infection with STH and schistosome parasites.Graphical

Evaluation of faecal lactoferrin as a morbidity biomarker in Schistosoma mansoni infection.

Lactoferrin is an 80 KDa iron-binding glycoprotein that plays a significant role in the innate immune system and is considered to be an important microbicide molecule. This study aimed to assess the concentration of lactoferrin in Schistosoma mansoni-infected cases before and after praziquantel treatment. A cross-sectional study was carried out on 250 individuals aged from 5 to 30 years. Stool samples were examined for the presence of parasitic infections using Kato-Katz and formalin ethyl acetate techniques. All S. mansoni-positive cases were treated with praziquantel and stool samples were recollected 21 days later. Faecal lactoferrin level was determined before and after treatment. The prevalence of S. mansoni infection was 14.4%. Among 36 participants infected with S. mansoni, the cure rate was 91.7%. A statistically significant difference in the mean lactoferrin level before and after treatment was detected (1648.95 pg/ml ± 656.5 vs. 1162.8pg/ml ± 356.8). This difference was statistically significant in the middle and older age groups, in males and in the absence of coinfection with other parasites. Lactoferrin could be a promising biomarker associated with S. mansoni infection, however, it could not be used to assess the severity of infection.

Safety Surveillance of Mass Praziquantel and Albendazole Co-Administration in School Children from Southern Ethiopia: An Active Cohort Event Monitoring.

Preventive chemotherapy (PC) with praziquantel and albendazole co-administration to all at-risk populations is the global intervention strategy to eliminate schistosomiasis and soil-transmitted helminth (STH) from being public health problems. Due to weak pharmacovigilance systems, safety monitoring during a mass drug administration (MDA) is lacking, especially in sub-Saharan Africa. We conducted large-scale active safety surveillance to identify the incidence, types, severity, and associated risk factors of adverse events (AEs) following praziquantel and albendazole MDA in 5848 school children (5-15 years old). Before MDA, 1484 (25.4%) children were prescreened for S. mansoni and STH infections, of whom 71.8% were infected with at least one parasite; 34.5% (512/1484) had S. mansoni and 853 (57.5%) had an STH infection. After collecting the baseline socio-demographic, clinical, and medical data, including any pre-existing clinical symptoms, participants received single dose praziquantel and albendazole MDA. Treatment-associated AEs were actively monitored on days 1 and 7 of the MDA. The events reported before and after the MDA were cross-checked and verified to identify MDA-associated AEs. The cumulative incidence of experiencing at least one type of MDA-associated AE was 13.3% (95% CI = 12.5-14.2%); 85.5%, 12.4%, and 1.8% of reported AEs were mild, moderate, and severe, respectively. The proportion of experiencing one, two, or ≥ three types of AEs was 57.7%, 34.1%, and 8.2%, respectively. The cumulative incidence of AEs in S. mansoni- and (17.0%) and STH (14.1%)-infected children was significantly higher (p &lt; 0.001, χ2 = 15.0) than in non-infected children (8.4%). Headache, abdominal pain, vomiting, dizziness, and nausea were the most common AEs. Being female, older age, having S. mansoni or STH infection were significant predictors of MDA-associated AEs. In summary, praziquantel and albendazole co-administration is generally safe and tolerable. MDA-associated AEs are mostly mild-to-moderately severe and transient. The finding of few severe AEs and significantly high rates of AEs in helminth-infected children underscores the need to integrate pharmacovigilance in MDA programs, especially in high schistosomiasis and STH endemic areas.

Diagnosis of Schistosomiasis without a Microscope: Evaluating Circulating Antigen (CCA, CAA) and DNA Detection Methods on Banked Samples of a Community-Based Survey from DR Congo.

Detection of Schistosoma eggs in stool or urine is known for its low sensitivity in diagnosing light infections. Alternative diagnostics with better sensitivity while remaining highly specific, such as real-time PCR and circulating antigen detection, are progressively used as complementary diagnostic procedures but have not yet replaced microscopy. This study evaluates these alternative methods for the detection of Schistosoma infections in the absence of microscopy. Schistosomiasis presence was determined retrospectively in 314 banked stool and urine samples, available from a previous survey on the prevalence of taeniasis in a community in the Democratic Republic of the Congo, using real-time PCR, the point-of-care circulating cathodic antigen (POC-CCA) test, as well as the up-converting particle lateral flow circulating anodic antigen (UCP-LF CAA) test. Schistosoma DNA was present in urine (3%) and stool (28%) samples, while CCA (28%) and CAA (69%) were detected in urine. Further analysis of the generated data indicated stool-based PCR and the POC-CCA test to be suitable diagnostics for screening of S. mansoni infections, even in the absence of microscopy. A substantial proportion (60%) of the 215 CAA-positive cases showed low antigen concentrations, suggesting that even PCR and POC-CCA underestimated the “true” number of schistosome positives.

Fine-scale mapping of Schistosoma mansoni infections and infection intensities in sub-districts of Makenene in the Centre region of Cameroon.

BackgroundSchistosomiasis control relies mainly on mass drug administration of Praziquantel (PZQ) to school aged children (SAC). Although precision mapping has recently guided decision making, the sub-districts and the epidemiological differences existing between bio-ecological settings in which infected children come from were not taken into consideration. This study was designed to fill this gap by using POC-CCA and KK to comparatively determine the prevalence and infection intensities of Schistosoma mansoni (S. mansoni) and to perform fine-scale mapping of S. mansoni infections and its infection intensities with the overarching goal of identifying sub-districts presenting high transmission risk where control operations must be boosted to achieve schistosomiasis elimination.MethodologyDuring a cross- sectional study conducted in Makenene, 1773 stool and 2253 urine samples were collected from SAC of ten primary schools. S. mansoni infections were identified using the point of care circulating cathodic antigen (POC-CCA) and Kato-Katz (KK) test respectively on urine and stool samples. Geographical coordinates of houses of infected SAC were recorded using a global position system device. Schistosome infections and infection intensities were map using QGIS software.ResultsThe prevalence of S. mansoni inferred from POC-CCA and KK were 51.3% and 7.3% respectively. Most infected SAC and those bearing heavy infections intensities were clustered in sub-districts of Baloua, Mock-sud and Carrière. Houses with heavily-infected SAC were close to risky biotopes.ConclusionThis study confirms the low sensitivity of KK test compared to POC-CCA to accurately identify children with schistosome infection and bearing different schistosome burden. Fine-scale mapping of schistosome infections and infection intensities enabled to identify high transmission sub-districts where control measures must be boosted to reach schistosomiasis elimination.

Schistosomiasis Mansoni-Recruited Eosinophils: An Overview in the Granuloma Context.

Eosinophils are remarkably recruited during schistosomiasis mansoni, one of the most common parasitic diseases worldwide. These cells actively migrate and accumulate at sites of granulomatous inflammation termed granulomas, the main pathological feature of this disease. Eosinophils colonize granulomas as a robust cell population and establish complex interactions with other immune cells and with the granuloma microenvironment. Eosinophils are the most abundant cells in granulomas induced by Schistosoma mansoni infection, but their functions during this disease remain unclear and even controversial. Here, we explore the current information on eosinophils as components of Schistosoma mansoni granulomas in both humans and natural and experimental models and their potential significance as central cells triggered by this infection.

Parasitological and malacological surveys to identify transmission sites for Schistosoma mansoni in Gomma District, south-western Ethiopia

Schistosomiasis is a neglected tropical disease that disproportionately affects the poorest people in tropical and subtropical countries. It is a major parasitic disease causing considerable morbidity in Ethiopia. Despite significant control efforts, schistosomiasis transmission is still widespread in many rural areas of the country. The aim of this study was to determine the prevalence and intensity of intestinal schistosomiasis among schoolchildren, as well as to identify schistosomiasis transmission sites in Gomma District, southwestern Ethiopia. Between October 2018 and September 2019, cross-sectional parasitological and malacological surveys were conducted in the study area. The study comprised 492 school-children aged 6 to 15 years old from four primary schools in Gomma District. To identify and quantify eggs of Schistosoma mansoni from the children, stool specimens were collected and processed using double Kato-Katz thick smears. Water bodies adjacent to human settlements in the study area were surveyed for snail intermediate hosts of S. mansoni. Morphological identification of collected snails was conducted, followed by examining their infection status using a dissecting microscope. The overall prevalence of S. mansoni infection was 73.8% (95%CI: 69.9–77.7%) and 41.6% of them had moderate-to-heavy infections. The prevalence of S. mansoni infection differed considerably by age group, with the older age groups (12–15) having a higher prevalence than the younger age groups (6–11) (p < 0.001). The prevalence of infection also varied significantly among schools; Dedo Ureche had the highest prevalence (86.9%) (p = 0.034), while Goga Kilole had relatively the lowest prevalence of S. mansoni infection (59.6%) (p = 0.003). A total of 1463 Biomphalaria pfeifferi snails were collected from 11 survey sites throughout the study area, with 357 (24.4%) of the snails shedding schistosomes cercariae. Despite intensified efforts to scale up mass drug administration in Ethiopia, this study reported high levels of S. mansoni infection among schoolchildren and snail intermediate hosts in rural communities in Gomma. Such a high infection rate warrants pressing needs for targeted and integrated interventions to control the disease in the area.

Distribution and seasonal abundance of Biomphalaria snails and their infection status with Schistosoma mansoni in and around Lake Tana, northwest Ethiopia

Biomphalaria snails, namely B. pfeifferi and B. sudanica, are the principal intermediate hosts for Schistosoma mansoni infection in Ethiopia. Epidemiological studies of Biomphalaria snails and their infection status with S. mansoni is vital for public health planning. This study aimed to assess the spatial and seasonal abundance of Biomphalaria snails as well as their infection status with S. mansoni around Lake Tana, northwest Ethiopia. Malacological survey was conducted from January 2021 to December 2021 in ten different collection sites in and around Lake Tana. Snail collection was performed for 20 min from each collection site seasonally (four times in a year) using a standard scoop and handpicking from aquatic vegetation. All collected snails were carefully examined based on their morphological features and all live Biomphalaria snails were subjected to cercariae shedding experiment. Descriptive statistics were used to determine the prevalence of S. mansoni infection and its relationship with snail collection sites and seasons. A total of 3886 freshwater snails were collected from ten collection sites around Lake Tana. Out of the total snails collected, 1606 (41.3%; 95% CI 39.77–42.89%) were Biomphalaria spp. The highest (374) and the lowest numbers (98) of Biomphalaria snails were collected from Shinne River and Qunzela Lakeshore, respectively. Out of the 1375 live Biomphalaria snails, 14.4% (95% CI 12.59–16.37%) snails shed cercariae, but only 4.87% (95% CI 3.79–6.15%) were cercariae of S. mansoni. The infection prevalence of S. mansoni ranged from 10.59% at the Cherechera site to 1.49% at Gumara River. Biomphalaria snail infections with S. mansoni cercariae were observed throughout the season, the highest and the lowest infection rates being in the spring and summer seasons. Significant differences in the prevalence of S. mansoni infection in Biomphalaria snails were observed across study sites and seasons (p < 0.05). Biomphalaria snails were the most abundant freshwater snails found in nearly all of snail collection sites throughout the year. It was revealed that nearly five percent of Biomphalaria snails were infected with S. mansoni cercariae. This study highlights the importance of appropriate snail control strategies to support the ongoing prevention and control of schistosomiasis around Lake Tana.

Role of IL-17A in enhancing liver fibrosis induced by TGF-β1 and IL-13 in Schistosoma mansoni infected mice

Schistosoma mansoni liver fibrosis is a complicated multicellular process involving numerous cytokines, chemokines, and growth factors. Transforming growth factor beta 1 (TGF-1) and interleukin (IL)-13 have been identified as critical pro-fibrotic mediators in many studies. IL-17A was linked to enhanced TGF- and IL-13-induced pathologies. This case-control study aimed to explore the effect of IL-17A on TGF- and IL-13-induced liver fibrosis during experimentally schistosomiasis mansoni infection. A total of 40 laboratory-bred female C57BL/6 mice were divided into four equal groups (G), G1 non-infected, G2 infected wild type (WT), G3 infected/anti-IL-17 monoclonal antibodies (mAb) and G4 treated mice. Mice were infected percutaneously with 40±5 cercariae per mouse. Neutralizing IL-17 mAb was administered to G3 intraperitoneally 3 weeks after infection and then every third day until 2 days before sacrification; mice of G4 were treated with a single dose of praziquantel. Serum levels of TGF-, IL-13, IL-17A, and proinflammatory cytokines were measured by ELISA. Liver granulomas were identified by hematoxylin-eosin stain and measured by an ocular micrometer. There was a significantly increased serum concentration of TGF-, IL-13, and IL-17A in infected WT mice (P<0.01), but praziquantel treatment reduced cytokine levels (P<0.03). Neutralization of IL-17A activity remarkably reduced serum concentrations of TGF- and IL-13 (P <0.03) resulting in improved liver functions and reduced granuloma size. Secretion of IL-IL-6 and TNF-were markedly enhanced by infection, however, mice that received anti-mouse IL-17 mAb displayed fewer inflammatory mediators (P<0.03). In conclusion, IL-17A might contribute to the progress of liver fibrosis by enhancing the profibrotic effect of TGF- and IL-13 in mice infected with S. mansoni.

Parasitological and histopathological studies to the effect of aqueous extract of Moringa oleifera Lam. leaves combined with praziquantel therapy in modulating the liver and spleen damage induced by Schistosoma mansoni to male mice

This study assessed the effectiveness of an aqueous extract of Moringa Oleifera Lam. leaves (MOL) alone or in combination with praziquantel (PZQ) drug targeting–infected mice with Schistosoma mansoni-induced liver and spleen damage. Mice were divided into eight groups control mice group treated orally with saline. PZQ group: non-infected mice treated orally with 300 mg/kg bwt PZQ three consecutive days. MOL group: non-infected mice treated orally with 150 mg/kg bwt MOL extract for 15 days. PZQ/ MOL group: non-infected mice treated orally with 300 mg/kg bwt PZQ for three consecutive days and 150 mg/kg bwt MOL extract for 15 days. IF group: infected mice with 100 cercariae/mouse of the Egyptian strain of S. mansoni. IF/PZQ group infected mice with S. mansoni cercariae and treated orally with 300 mg/kg bwt PZQ for three consecutive days. IF/MOL group: infected mice with S. mansoni cercariae treated orally with 150 mg/kg bwt MOL extract for 15 days. IF/PZQ +MOL group: infected mice with S. mansoni cercariae treated orally with 300 mg/kg bwt PZQ for three consecutive days and 150 mg/kg bwt MOL extract for 15 days. Blood, liver, spleen, worm, and eggs were collected at the end of the experimental period. Treatment of infected mice with MOL and PZQ together significantly reduced the number of ova/g tissue and eliminated the parasites. In addition, the liver and spleen of infected mice showed less histopathological alteration and immunohistochemical expression of nuclear factor kappa β (NF-Kβ). We can conclude that MOL extract combined with PZ has a curative effect on S. mansoni infection and helped to lessen its pathological effects.

Determinants of Schistosoma mansoni transmission in hotspots at the late stage of elimination in Egypt

BackgroundIn certain settings, the prevalence and severity of schistosoma infection do not lessen despite repeated rounds of preventative chemotherapy; these areas are known as hotspots. This study aimed to investigate the role of human practices, besides environmental and malacological factors, in the maintenance of the Schistosoma mansoni infection transmission chain in hotspot areas in Egypt.MethodsThis cross-sectional study was conducted between July and November 2019 in Kafr El-Sheikh Governorate, Egypt. A pre-designed structured interviewing questionnaire was used to collect humanitarian data. Stool samples were collected from children aged 6–15 years on three successive days and examined using the Kato-Katz technique. Simultaneously, water and snail samples were taken from watercourses surrounding houses. Snails were identified based on their shell morphology and structure and tested for cercaria shedding. Water samples were analyzed for their physicochemical and biological characteristics.ResultsA total of 2259 fecal samples (1113 in summer and 1146 in fall) were collected from 861 children. About 46.9% of the participants were males, and 31.8% were aged 6–10 years. The prevalence of S. mansoni infection was higher during the summer than during the fall (19.1% vs 7.2%, respectively, P < 0.01). The intensity of infection (light, moderate, and heavy) during summer versus fall was (93.55 vs 89.38%, 6.45 vs 8.85%, and 0.00% vs 1.77%), respectively (P < 0.05). A higher prevalence of human infection was observed among males than females [OR = 1.63, 95% confidence interval (CI):1.10–2.40, P = 0.015], children aged 11–15 years than among their counterparts aged 6–10 years (OR = 2.96, 95% CI: 1.72–5.06, P < 0.001), and mothers with a low level of education (OR = 3.33, 95% CI: 1.70–6.52, P < 0.001). The main identified risk factors were contacting the main body of water-canal for washing clothes (OR = 1.81, 95% CI: 1.12–2.49, P = 0.015), land irrigation (OR = 2.56, 95% CI: 1.32–4.96, P = 0.004), water collection (OR = 2.94, 95% CI: 1.82–4.73, P < 0.001), bathing (OR = 2.34, 95% CI: 1.21–4.31, P = 0.009), and garbage disposal (OR = 2.38, 95% CI:1.38–4.12, P < 0.001). The count of Biomphalaria alexandrina was distinct between seasons (P < 0.01) in consistent with statistically significant differences in water temperature, salinity, turbidity, the total concentration of coliforms, depth, velocity, and water level (P < 0.01). The presence of grasses and duckweeds was significantly associated with snail infection (P = 0.00 l). Significant effects of water depth, pH, temperature, and total dissolved solids on snail count were also observed (P < 0.05).ConclusionsThe persistence of the infection is due to adoption of risky behaviors and environmental factors that enhance snail survival and infection. Schistosomiasis elimination in hotspots requires an integrated control approach that combines preventive chemotherapy with other complementary measures.

Optimizing Implementation of Preventive Chemotherapy against Soil-Transmitted Helminthiasis and Intestinal Schistosomiasis Using High-Resolution Data: Field-Based Experiences from Côte d'Ivoire.

Background: Despite efforts to control neglected tropical diseases (NTDs) using preventive chemotherapy (PC), soil-transmitted helminthiases and schistosomiasis remain widely prevalent in sub-Saharan Africa. The current PC regimen in endemic settings is defined based on health district-level prevalence. This work aims to highlight the need for high-resolution data when elimination, rather than morbidity control, is the targeted goal. Methodology: Cross-sectional parasitological surveys were conducted from July to August 2019 and from September to October 2019, respectively, across the entire Dabou and Jacqueville health districts in southern Côte d’Ivoire. From every village, 60 school-aged children (6–15 years) were randomly selected and invited to provide one fresh stool sample, whereof duplicate Kato–Katz thick smears were prepared and read by two independent technicians. Principal Findings: 4338 school-aged children from 77 villages were screened from the Dabou (n = 2174; 50.12%, 39 villages) and Jacqueville (n = 2164; 49.88%, 38 villages) health districts. The prevalence of any soil-transmitted helminth (STH) infection was 12.47% and 11.09% in the Dabou and Jacqueville health districts, respectively. Species-specific district-level prevalence remained below 10%, varying between 0.51% (hookworm in Jacqueville) and 9.06% (Trichuris trichiura in Dabou). However, when considering sub-districts or villages only, several STH infection hotspots (five sub-districts with ≥20% and four villages with more than 50% infected) were observed. Schistosoma mansoni infection was found in less than 1% of the examined children in each health district. Conclusions/Significance: We conclude that keeping health district-level prevalence as a reference for PC implementation leaves many high-risk sub-districts or villages requiring PC (≥20% prevalence) untreated. To avoid maintaining those high-risk villages as STH reservoirs by skipping control interventions and jeopardizing the successes already achieved in STH control through PC during the past two decades, precision mapping is required. Further investigation is needed to assess cost-efficient approaches to implement small-scale disease surveillance.

Schistosoma mansoni Epidemiology Among Snails, Rodents and Children: A One Health Approach.

BackgroundSchistosoma is one of the prevalent parasitic infection in humans and animals. Schistosomiasis in children is particularly serious and results in liver and spleen enlargement, anemia, stunting, reduced ability to learn and death. The aim of this study was to measure the prevalence and distribution of schistosomiasis in children, rodents and snail populations in Aleffa and Takusa districts, north-west Ethiopia.MethodsDisease status and exposure were simultaneously measured from December 2020 to December 2021. School children's stool specimens were collected for schistosomiasis examination by Kato Katz and formal-ether techniques. Live rodents and snails were trapped and collected in search of adult schistosoma, eggs, and cercariae, respectively. Multiple logistic regression analytic technique by using SPSS version 20 was conducted.ResultsOf 460 stool specimens examined, 116 (25.22) were found positive for S. mansoni infection. In the present finding, the possible determinants for the occurrence of intestinal schistosomiasis in school children were female sex (AOR = 1.09, 95% CI: 1.37–2.96); working with bare foot (AOR = 1.21, 95% CI: 1.08–1.52); skin cut/abrasion history (AOR = 3.6, 95% CI: 1.08–7.43) and swimming habit (AOR = 1.58, 95% CI: 1.33–1.99). The overall (n = 108) rodent prevalence of S. mansoniwas 23 (21.3%). Only 6 snails were shedding the infective stage of schistosoma cercariae.ConclusionThe study revealed that there is a moderate prevalence of schistosomiasis in different hosts. Thus, multi-host intervention is crucial to achieving the goal of interrupting transmission of schistosomiasis in the study area. Further research to better understand and exploit the broader environmental, ecological context and encompassing dynamic interactions between all hosts over time will be crucial for building predictive models beyond the known fact of having or not having reservoirs/hybridization of schistosoma in our study area.

Prevalence of Intestinal Parasitic Infections and Associated Risk Factors Among Schoolchildren in Ibb Governorate, Southwest Yemen: A Cross-Sectional Study.

IntroductionIntestinal parasitic infections (IPIs) among schoolchildren are important public health problem, especially in developing countries, and monitoring of such infections and associated risk factors are necessary for intervention strategies. In line with this view, the aim of this study was to determine the prevalence of IPIs and associated risk factors among schoolchildren in Ibb governorate, southwest Yemen.MethodsA cross-sectional study was carried out during February to April 2020 on 600 schoolchildren selected from 6 districts of Ibb governorate. Fecal specimens were examined using saline and iodine wet mount and formal-ether concentration techniques. Socio-demographic data were collected using pre-designed, structured questionnaires. The results were analyzed using SPSS for Windows version 25 (SPSS Inc., Chicago, IL, USA).ResultsOut of 600 participants, the overall prevalence of IPIs was 66.3% (398/600). The prevalence rate of protozoan infections (56.3%, 338/600) was largely higher than helminthic infections (10%, 60/600). The most common intestinal parasite was E. histolytica/dispar (28.5%, 171/600). S. mansoni infection showed higher infection rate in males (5.3%) than in females (0.4%), with statistically significant difference (P = 0.001). Univariate analysis showed that the age was only significantly associated with protozoan infections, with statistically significant differences (P = 0.002). Regarding to clinical symptoms, the presence of IPIs was significantly associated with diarrhea, dysentery, and abdominal pain.ConclusionThe present study revealed that there was a relatively high prevalence of IPIs, especially protozoan parasites, in schoolchildren of the study area, with E. histolytica/dispar being the most prevalent parasite. The results showed that age was only significantly associated with IPIs. According to the results of this study, IPIs are still among the main public health problems in the study area. Thus, effective prevention and control strategies are important to reduce the incidence of IPIs in this area of the country.

Profiling the serum proteome during Schistosoma mansoni infection in the BALB/c mice: A focus on the altered lipid metabolism as a key modulator of host-parasite interactions.

Schistosomiasis represents a condition in which every aspect of the disease, starting from skin invasion of the cercariae to egg laying by adult worms, incites a tissue response from the vertebrate host. This response, whether acute or chronic, leads to the appearance of reporter molecules of tissue injury in bodily fluids that could be surveyed as markers for disease diagnosis, status and prognosis. In this scenario, the serum proteome associated with a schistosome infection remains poorly explored; particularly by the use of high-throughput mass spectrometric instrumentation. In this study, we aimed to comparatively examine the serum proteome of control versus infected BALB/c mice, spanning the interval between the onset of egg laying and the peak of the acute phase of infection. Compositional analysis of the sera, using one dimensional reversed-phase fractionation of tryptic peptides coupled to mass spectrometry, allowed identification of 453 constituents. Among these, over 30% (143 molecules) were differentially present comparing sera from infected and non-infected mice, as revealed by quantitative label-free shotgun approach. The majority of proteins exhibiting altered levels was categorised as belonging to immune response (acute phase-related proteins) followed by those linked to lipid transport and metabolism. Inspection of the lipid profile from control and infected individuals demonstrated more pronounced and significant alterations in triglycerides, VLDL and HDL fractions (p<0,001), attesting for a disturbance in circulating lipid molecules, and suggesting a key role in host-parasite interactions. Our findings provide a global view of the serum proteome in the context of experimental schistosomiasis during the acute phase of infection. It contributes by listing key molecules that could be monitored to inform on the associated inflammatory disease status. We hope it will shed light into uncovered aspects of the Schistosoma mansoni parasitism in the vertebrate host, particularly those related to modulation of the lipid metabolism mediating immune responses.

Hematological and Biochemical changes in Schistosoma mansoni infected patients at Haik Primary Hospital, North-East Ethiopia: A comparative cross-sectional study.

Schistosomes are blood dwelling parasites that affect more than 260 million people globally, and over 800 million people are at risk of infection in 74 countries. It causes acute and chronic debilitating diseases. The parasite is reported to alter the hematological and biochemical parameters in humans. Therefore, this study was aimed to evaluate the hematological and biochemical changes in S. mansoni infected adult patients compared to apparently healthy controls. A comparative cross-sectional study was conducted at Haik Primary Hospital from February to April 2021. One hundred and eighty study participants consisting of 90 S. mansoni infected patients and 90 apparently healthy controls were recruited using systematic random sampling method. Socio-demographic characteristics and other variables were collected using questionnaires. Stool sample was examined microscopically to detect S. mansoni infection using direct wet mount and Kato Katz technique. In apparently healthy controls, S. mansoni infection was rule out using direct wet mount and Kato Katz technique. Moreover, the intensity of S. mansoni infection was assessed using Kato Katz technique. Blood sample was collected from each study participant to determine the hematological and biochemical profiles. Data were entered in to Epi Data version 3.1 and analyzed using SPSS version 26.0 software. Kolmogorov-Smirnov and Shapiro Wilk normality tests were done to assess the distribution of continuous variables. The Mann-Whitney U test and Kruskal Wallis H test was done to compare the differences among nonnormally distributed variables between S. mansoni infected patients and healthy controls. P-values <0.05 at 95%CI were considered as statistically significant. The mean age (SD) of S. mansoni infected patients and apparently healthy controls was 30.33 (±12.26) and 31.2 (±12.85) years old, respectively. The prevalence of anemia, and thrombocytopenia among S. mansoni infected patients were 23.3% and 26.7%, respectively. Erythrocytic sedimentation rate (ESR) was significantly elevated among S. mansoni infected patients than apparently healthy controls. The median white blood cell count, red blood cell count, red blood cell indices, and platelet indices were significantly lower among S. mansoni infected patients compared to apparently healthy controls (P<0.05). On the other hand, the median eosinophil count was significantly elevated among S. mansoni infected patients compared to apparently healthy controls (P<0.05). This study also showed significantly elevated values of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and direct bilirubin and lower albumin, total cholesterol and triglycerides among S. mansoni infected patients compared to apparently healthy controls. Kruskal Wallis H test showed a significant difference in the median of most hematological and biochemical parameters between moderate and heavy intensity of infection with light intensity of infection and apparently healthy controls. The findings of this study showed significantly altered hematological values and liver function tests among S. mansoni infected patients compared to apparently healthy controls. Therefore, screening of S. mansoni infected patients for various hematological and biochemical parameters and providing treatment to the underlying abnormalities is very crucial to avoid schistosomiasis associated morbidity and mortality.

In Vivo Evaluation of Praziquantel-Loaded Solid Lipid Nanoparticles against S. mansoni Infection in Preclinical Murine Models.

This study aimed to develop and assess the long-term stability of drug-loaded solid lipid nanoparticles (SLNs). The SLNs were designed to extend the release profile, overcome the problems of bioavailability and solubility, investigate toxicity, and improve the antischistosomal efficacy of praziquantel. The aim was pursued using solvent injection co-homogenization techniques to fabricate SLNs in which Compritol ATO 888 and lecithin were used as lipids, and Pluronic F127 (PF127) was used as a stabilizer. The long-term stability effect of the PF127 as a stabilizer on the SLNs was evaluated. Dynamic light scattering (DLS) was used to determine the particle size, stability, and polydispersity. The morphology of the SLNs was examined through the use of transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The chemical properties, as well as the mechanical, thermal, and crystal behaviours of SLNs were evaluated using FTIR, ElastoSens Bio2, XRPD, DSC, and TGA, respectively. SLNs with PF127 depicted an encapsulation efficiency of 71.63% and a drug loading capacity of 11.46%. The in vitro drug release study for SLNs with PF127 showed a cumulative release of 48.08% for the PZQ within 24 h, with a similar release profile for SLNs’ suspension after 120 days. DLS, ELS, and optical characterization and stability profiling data indicate that the addition of PF127 as the surfactants provided long-term stability for SLNs. In vitro cell viability and in vivo toxicity evaluation signify the safety of SLNs stabilized with PF127. In conclusion, the parasitological data showed that in S. mansoni-infected mice, a single (250 mg/kg) oral dosage of CLPF-SLNs greatly improved PZQ antischistosomal efficacy both two and four weeks post-infection. Thus, the fabricated CLPF-SLNs demonstrated significant efficiency inthe delivery of PZQ, and hence are a promising therapeutic strategy against schistosomiasis.

The prevalence of Schistosoma mansoni infection among adults with chronic non-communicable diseases in Malawi

BackgroundSchistosomiasis is a parasitic infectious disease caused by flatworms of the Schistosoma genus. The global burden of schistosomiasis is high. In Malawi, schistosomiasis is among the top 20 causes of outpatient department visits in health facilities. Schistosomiasis is among the most important but neglected causes of non-communicable diseases (NCD) peculiar to tropical endemic settings. While much is known about the contribution of S. haematobium to the NCD burden in Malawi, the role of S. mansoni remains largely unknown.MethodsWe conducted a cross-sectional study at Mangochi District Hospital. Adults over 18 years diagnosed with NCDs (n = 414), admitted or attending weekly outpatient clinics were recruited between August 2021 and February 2022. Data were collected on sociodemographic characteristics, medical history, body weight, blood pressure, and fasting blood glucose. Stool and midstream urine were collected for Kato–Katz (KK) microscopy and urine point of care-circulating cathodic antigen (POC-CCA) tests, respectively. We computed prevalence of S. mansoni as number of positive KK and CCA tests, each divided by total submitted samples. Univariate and multivariable logistic regression were done to evaluate risk factors of NCDs and association between S. mansoni infection and NCDs.ResultsWe recruited 414 participants, mean age 57 years (SD 16), 67% of whom were female. Prevalence of S. mansoni based on urine CCA was 15% (95% CI: 11–19) and 0% on KK microscopy. Hypertension was the most common condition with a prevalence of 85% (95% CI: 81–89), followed by diabetes mellitus with a prevalence of 42% (95% CI: 37–46) and heart disease with a prevalence of 3% (95% CI: 2–5). S. mansoni infection was not significantly associated with hypertension (OR: 1.2, 95% CI: 0.5–3.1), diabetes (OR: 0.6, 95% CI: 0.3–1.10) or heart disease (OR: 2.0, 95% CI: 0.4–10).ConclusionsWe observed moderate prevalence of S. mansoni infection among adults in the study per WHO classification of endemicity. This is within the range observed in children in Mangochi from 10 to 56.7%.

Nutritional effects of invasive macrophyte detritus on Schistosoma mansoni infections in snail intermediate hosts

Nutritional effects of invasive macrophyte detritus on Schistosoma mansoni infections in snail intermediate hosts