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In countries of high endemicity of the soil-transmitted helminth parasites Ascaris lumbricoides, Trichuris trichiura, and hookworm, preventive chemotherapy (i.e., repeated administration of anthelmintic drugs to at-risk populations) is the main strategy to control morbidity. However, rapid reinfection of humans occurs after successful deworming, and therefore effective preventive measures are required to achieve public health goals with optimal efficiency and sustainability. We conducted a systematic review and meta-analysis to assess the effect of sanitation (i.e., access and use of facilities for the safe disposal of human urine and feces) on infection with soil-transmitted helminths. PubMed, Embase, ISI Web of Science, and the World Health Organization Library Database were searched without language restrictions and year of publication (search performed until December 31, 2010). Bibliographies of identified articles were hand-searched. All types of studies reporting data on sanitation availability (i.e., having access at own household or living in close proximity to sanitation facility), or usage, and soil-transmitted helminth infections at the individual level were considered. Reported odds ratios (ORs) of the protective effect of sanitation on soil-transmitted helminth infections were extracted from the papers or calculated from reported numbers. The quality of published studies was assessed with a panel of criteria developed by the authors. Random effects meta-analyses were used to account for observed heterogeneity. Thirty-six publications, consisting of 39 datasets, met our inclusion criteria. Availability of sanitation facilities was associated with significant protection against infection with soil-transmitted helminths (OR  =  0.46 to 0.58). Regarding the use of sanitation, ORs of 0.54 (95% confidence interval [CI] 0.28-1.02), 0.63 (95% CI 0.37-1.05), and 0.78 (95% CI 0.60-1.00) were determined for T. trichiura, hookworm, and A. lumbricoides, respectively. The overall ORs, combining sanitation availability and use, were 0.51 (95% CI 0.44-0.61) for the three soil-transmitted helminths combined, 0.54 (95% CI 0.43-0.69) for A. lumbricoides, 0.58 (95% CI 0.45-0.75) for T. trichiura, and 0.60 (95% CI 0.48-0.75) for hookworm. Despite a number of limitations (e.g., most studies used a cross-sectional design and were of low quality, with potential biases and considerable heterogeneity), our results reveal that sanitation is associated with a reduced risk of transmission of helminthiases to humans. Access to improved sanitation should be prioritized alongside preventive chemotherapy and health education to achieve a durable reduction of the burden of helminthiases.

Soil-transmitted helminths, like Ascaris lumbricoides, are significant contributors to disease burden in low- and middle-income countries (LMICs). Infections are associated with morbidity and mortality in children and are often transmitted through eggs in fecally contaminated soil. Interventions, like replacing household soil floors with cement-based alternatives, may reduce exposure to A. lumbricoides eggs, but there are currently no estimates on the removal or survival of Ascaris species eggs on cement-based surfaces. This study addresses that knowledge gap by evaluating the removal of Ascaris suum eggs from mopping and the survival of A. suum eggs on two cement-based mixes: an traditional mortar and a mortar with fly ash, which provides a more sustainable alternative to the traditional mortar mix. We assessed egg survival at two temperatures representing the dry (15°C) and wet (34°C) seasons in Bangladesh using two different egg enumeration methods. After mopping, a mean of 95.6% (SD = 4.0%) of viable eggs were removed from surfaces, with no significant differences between cement-based mixes (p = 0.51). The mean first-order decay rate constants ( k ) of A. suum eggs across all conditions was 0.029 day -1 (SD = 0.074 day -1 ). Values of k were similar between mix designs (p = 0.62) but varied significantly between temperatures (p = 4.2x10 -25 ) and egg enumeration methods (p = 2.4x10 -8 ). The k values were greater at 34°C compared to at 15°C, where they showed no significant inactivation. Our k values were comparable to those reported previously for different matrices, indicating comparable inactivation of Ascaris species eggs on cement-based surfaces compared to liquid and semi-solid matrices. These results provide some of the first estimates of removal efficiencies and decay rate constants in realistic environmental conditions for Ascaris species on surfaces while supporting the use of mortar mix designs with fly ash in interventions to reduce Ascaris species transmission in rural LMIC households.

Human ascariasis is the most prevalent geohelminthiasis worldwide, affecting approximately 446 million individuals. In regions with endemic prevalence, the majority of infected adults are frequently exposed to the parasite and tend to have a low parasite load. Further studies are necessary to provide more evidence on the dynamics of infection and to elucidate the possible mechanisms involved in regulating protection, especially during the acute phase, also known as larval ascariasis. The aim of this study is to compare the impact of lung function between single and multiple infections in a murine model. We infected BALB/c mice considering the frequency of exposures: single-exposure-SI; twice-exposures-RE 2x and thrice-exposures-RE 3x, and considering the doses of infection: 25 eggs-RE 25; 250 eggs-RE 250 and 2,500 eggs-RE 2500, followed by infection challenge with 2,500 eggs. From this, we evaluated: parasite burden in lungs, cellular and humoral response, histopathological and physiological alterations in lungs. The main results showed a reduction of parasite burden in the reinfected groups compared to the single-infected group, with protection increasing with higher exposure and dose. Furthermore, the RE 250 group exhibited a decrease of parasite burden close to RE 2500, but with less tissue damage, displaying the most favorable prognosis among the reinfected groups. Our research indicates a dose-dependent relationship between antibody production and the intensity of the immune response required to regulate the parasite burden.

Soil-transmitted helminths (STH), i.e., Ascaris lumbricoides, Trichuris trichiura and hookworms are among the most prevalent Neglected Tropical Diseases (NTDs) in Ethiopia. Although pre-school aged children pay a high morbidity toll associated with STH infections, evidence on prevalence, intensity and intervention status is lacking in Ethiopia. This study, therefore, aimed to address these gaps to inform decision made on STH. We did a community-based cross-sectional study in five districts of Gamo Gofa zone, Southern Ethiopia; in January 2019. Data were collected using pre-tested questionnaire, and the Kato-Katz technique was used to diagnose parasites eggs in stool. Then, collected data were edited and entered into EpiData 4.4.2, and exported to SPSS software (IBM, version 25) for analysis. A total of 2462 PSAC participated in this study. Overall, the prevalence of STH was 23.5% (578/2462) (95% confidence interval (CI) = 21.8%-25.2%). As caris lumbricoides was the most prevalent (18.6%), followed by Trichuris trichiura (9.2%), and hookworms (3.1%). Of the total, 7.4% PSAC were infected with two STH species. Most of the positive cases with STH showed low infection intensities, while 15.1% ascariasis cases showed moderate infection intensities. The study found that 68.7% of PSAC were treated with albendazole. Also, household's level data showed that 39.4% used water from hand-dug well; 52.5% need to travel ≥30 minutes to collect water; 77.5% did not treat water, and 48.9% had no hand washing facility. In addition, almost 93% care givers achieved less than the mean knowledge and practice score (≤5) on STH prevention. This study showed that significant proportions of pre-school aged children are suffering from STH infections despite preventive chemotherapy exist at the study area. Also, gaps in the interventions against STH were highlighted. Thus, a call for action is demanding to eliminate STH among PSAC in Ethiopia by 2030.

Ascariasis is the most prevalent helminth infection in the world and leads to significant, life-long morbidity, particularly in young children. Current efforts to control and eradicate ascariasis in endemic regions have been met with significant challenges including high-rates of re-infection and potential development of anthelminthic drug resistance. Vaccines against ascariasis are a key tool that could break the transmission cycle and lead to disease eradication globally. Evolution of the Ascaris vaccine pipeline has progressed, however no vaccine product has been brought to human clinical trials to date. Advancement in recombinant protein technology may provide the first step in generating an Ascaris vaccine as well as a pan-helminthic vaccine ready for human trials. However, several roadblocks remain and investment in new technologies will be important to develop a successful human Ascaris vaccine that is critically needed to prevent significant morbidity in Ascaris-endemic regions around the world.

Soil transmitted helminths (STH) can affect over 50% of children in some parts of Tanzania. Control measures involve annual deworming campaigns in schools, but re-infection is rapid. This paper presents the design and baseline survey results of an ongoing school-based cluster-randomised controlled trial in Kagera region, NW Tanzania. The trial aims to determine whether the effect of routine deworming on the prevalence of Ascaris lumbricoides and Trichuris trichiura infections among school aged children can be sustained when combined with a behaviour change intervention promoting handwashing with water and soap. As part of the trial, a total of 16 schools were randomised to receive the intervention (N = 8) or as controls (N = 8). Randomisation was stratified per district and restricted to ensure pre-trial STH prevalence was balanced between study arms. The combination intervention to be tested comprises class-room based teacher-led health education, improvement of handwash stations, coloured nudges to facilitate handwashing and parental engagement sessions. The impact evaluation involves two cross-sectional surveys conducted at baseline and endline. The objectives of the baseline survey were: (i) to confirm whether the deworming campaign was successful, and identify and treat students still infected about 2 weeks after deworming, (ii) to document any baseline differences in STH prevalence between trial arms, and (iii) to assess handwashing behaviours, and access to water and sanitation at school and home. We randomly sampled 35 students per class in Grades 1-6 (an average of 200 children per school), stratified to ensure equal representation between genders. Assenting students were interviewed using a structured questionnaire and asked to provide a stool specimen. Results of the baseline survey conducted about 2 weeks after deworming shows balanced demographic and STH prevalence data across trial arms. We observed a low prevalence of ascariasis (< 5%) as expected; however, the prevalence of trichuriasis was still about 35% in both arms. The randomisation procedure was successful in achieving a balanced distribution of demographic characteristics and helminth infections between trial arms. The intervention is being rolled out. The current deworming treatment regimen may need to be revised with regards to the treatment of trichuriasis.

Soil-transmitted helminth (STH) infections remain a public health concern in sub-Saharan Africa. School-based mass drug administration (MDA) using the anthelminthic drug Mebendazole/Albendazole have succeeded in controlling morbidity associated to these diseases but failed to interrupt their transmission. In areas were filarial diseases are co-endemic, another anthelminthic drug (Ivermectin) is distributed to almost the entire population, following the community-directed treatment with ivermectin (CDTI) strategy. Since Ivermectin is a broad spectrum anthelmintic known to be effective against STH, we conducted cross-sectional surveys in two health districts with very contrasting histories of Ivermectin/Albendazole-based PC in order to investigate whether CDTI might have contributed in STH transmission interruption. Cross-sectional surveys were conducted in two health districts with similar socio-environmental patterns but with very contrasting CDTI histories (Akonolinga health district where CDTI was yet to be implemented vs. Yabassi health district where CDTI has been ongoing for two decades). Stool samples were collected from all volunteers aged >2 years old and analyzed using the Kato-Katz technique. Infections by different STH species were compared between Akonolinga and Yabassi health districts to decipher the impact of Ivermectin/Albendazole-based MDA on STH transmission. A total of 610 and 584 participants aged 2-90 years old were enrolled in Akonolinga and Yabassi health districts, respectively. Two STH species (Ascaris lumbricoides and Trichuris trichiura) were found, with prevalence significantly higher in Akonolinga health district (43.3%; 95% CI: 38.1-46.6) compared to Yabassi health district (2.5%; 95% CI: 1.1-5.1) (chi-square: 90.8; df: 1; p < 0.001). These findings (i) suggest that Mebendazole- or Albendazole-based MDA alone distributed only to at-risk populations might not be enough to eliminate STH, (ii) support the collateral impact of Ivermectin/Albendazole MDA on A. lumbricoides and T. trichiura infections, and (iii) suggest that Ivermectin/Albendazole-based PC could accelerate STH transmission interruption.

Objective The aim of this study was to determine the prevalence of soil transmitted helminthes among primary school children. School based cross-sectional study design was employed. A total of six hundred study subjects were selected by a multistage sampling method. Fresh stool specimens were collected using clean, dry and wide mouthed labeled stool cups. It was processed by Kato-Katz technique. The data were analyzed using SPSS version 20 and p-value < 0.05 was considered statistically significant. Result The overall prevalence of soil transmitted helminthes was 57 (9.5%). Hookworm was the most prevalent helminthes species isolated (4.2%) followed by A. lumbricoide (3%). The prevalence of Taenia species, T. trichiura , H. nana and E. vermicularis were; 1.2%, 0.5%, 0.7% and 0.8% respectively. The prevalence of the Soil transmitted helminthes infection was low and all cases of Soil transmitted infections in this study were with low infection intensity. This might be due to the preventive chemotherapy given to the school children.

•The construction of a chimeric protein leads to enhanced immune protection against Ascaris infection.•Vaccination with chimeric protein induced greater than 70% reduction in larval load after challenge.•Vaccine protection is associated with IgG response and reduced lung inflammation compared to controls. An estimated 400 million people are infected by parasites of the genus Ascaris and the existing control measures are inefficient. Vaccine development using B cell antigens is a promising strategy for increased protection against this parasite. The present study aimed at developing a chimeric protein capable of conferring protection against infection by Ascaris sp. For this purpose, we performed B-cell epitope predictions on previously described vaccine candidate proteins from Ascaris suum and the corresponding peptides were used to construct a chimeric protein. Female BALB / c mice were immunized subcutaneously in three doses at 10 day intervals with a vaccine formulation comprised of the chimeric protein together with monophosphoryl lipid A (MPLA). Control groups included protein alone, MPLA, or PBS. After challenge infection, animals vaccinated with chimeric protein plus MPLA showed a reduction of 73.54% of larval load in the lung compared to control group animals. Animals immunized with chimeric protein plus MPLA also display higher IgG response and a reduction in lung inflammation. Our study highlights how chimeric proteins containing more than one B cell epitope can enhance immune protection against helminthic infection and offer new approaches to the development of Ascaris vaccines.

Ascariasis is the most prevalent zoonotic helminthic disease worldwide, and is responsible for nutritional deficiencies, particularly hindering the physical and neurological development of children. The appearance of anthelmintic resistance in Ascaris is a risk for the target of eliminating ascariasis as a public health problem by 2030 set by the World Health Organisation. The development of a vaccine could be key to achieving this target. Here we have applied an in silico approach to design a multi-epitope polypeptide that contains T-cell and B-cell epitopes of reported novel potential vaccination targets, alongside epitopes from established vaccination candidates. An artificial toll-like receptor-4 (TLR4) adjuvant (RS09) was added to improve immunogenicity. The constructed peptide was found to be non-allergic, non-toxic, with adequate antigenic and physicochemical characteristics, such as solubility and potential expression in Escherichia coli . A tertiary structure of the polypeptide was used to predict the presence of discontinuous B-cell epitopes and to confirm the molecular binding stability with TLR2 and TLR4 molecules. Immune simulations predicted an increase in B-cell and T-cell immune response after injection. This polypeptide can now be validated experimentally and compared to other vaccine candidates to assess its possible impact in human health.