Soil-transmitted Helminth Infections Research Articles

Prevalence and Factors Associated With Soil-Transmitted Helminth Infections in the Northeast Region of Brazil

Objective: To estimate the positivity rate and the factors associated with the occurrence of soil-transmitted helminth infections in the Northeast region of Brazil to guide control measures. Theoretical Framework: Soil-transmitted helminth infections represent a significant burden on Brazilian public health and are associated with socioeconomic factors. Method: This ecological study, descriptive and explanatory in nature, analyzed data from 2017 to 2021 from the Information System of the Schistosomiasis Surveillance and Control Program (SISPCE), which also records data on soil-transmitted helminth infections. The data were collected through the Department of Informatics of the Unified Health System (DATASUS) and the Human Development Atlas of Brazil. Descriptive analyses of dependent variables were performed, as well as correlation analysis using Pearson’s correlation coefficient (r) to examine relationships between positivity rates for soil-transmitted helminth infections and socioeconomic and demographic indicators. Results and Discussion: The positivity rates for ascariasis, hookworm infection, and trichuriasis were 4.8% (N=113,748), 3.8% (N=88,678), and 1.5% (N=35,456), respectively. A strong correlation was observed between the number of soil-transmitted helminth cases and factors such as access to piped water, per capita income, and illiteracy rates. Research Implications: The findings highlight the need for a broad approach to controlling soil-transmitted helminths, emphasizing poverty reduction, housing improvements, and health education. Originality/Value: This study underscores the necessity of integrated actions in sanitation, education, and poverty alleviation, while revealing an unexpected correlation between income inequality and soil-transmitted helminth cases.

Discovery of Human PIM Kinase Inhibitors as a Class of Anthelmintic Drugs to Treat Intestinal Nematode Infections.

Soil-transmitted helminth (STH) infections affect one-fourth of the global population and pose a significant threat to human and animal health, with limited treatment options and emerging drug resistance. Trichuris trichiura (whipworm) stands out as a neglected disease, necessitating new drugs to address this unmet medical need. We discovered that several different chemical series of related human Provirus Integration sites for Moloney murine leukemia virus (PIM) family kinase inhibitors possess potent anthelmintic activity by using whole-worm motility assays. Systematic structure-activity relationship (SAR) studies based on the pan-PIM kinase inhibitor CX-6258 were conducted to identify compounds displaying improved in vitro motility inhibition of both adult hookworm (Ancylostoma ceylanicum) and adult whipworm (Trichuris muris) nematodes. A broad kinase selectivity screen of >450 human kinases confirms PIM1 kinase and others as potential targets for CX-6258 and analogues thereof. In addition, we demonstrated that CX-6258 significantly reduced worm burden and egg counts in the T. muris infection model of mice, establishing it as a new oral small molecule anthelmintic therapeutic.

High prevalence of soil-transmitted helminths among primary students in Ha Giang, Vietnam: A descriptive cross-sectional study.

Despite improvements in environmental sanitation and healthcare, the infection rate of soil-transmitted helminths (STHs) remains high in low socioeconomic regions of developing countries including Vietnam. This study aimed to determine the prevalence and intensity of STH infections among primary school children in Meo Vac, Ha Giang: a poor mountainous province in Vietnam. A descriptive cross-sectional study was conducted from October to November 2023, involving 400 participants. The Kato-Katz method was used to identify and quantify STH infections. Out of the 386 children assessed, 76.1% were infected with at least 1 type of STH. The most common infections were with Trichuris trichiura and Ascaris lumbricoides (47.0%). Mixed infections were identified in 121 children, with 77 cases of co-infection with A lumbricoides and T trichiura, 13 cases of A lumbricoides and hookworms, 8 cases of T trichiura and hookworms, and 23 cases involving all 3 STH types. Most infections were of light intensity, with a few moderate-intensity cases of A lumbricoides. Primary school students in Meo Vac, Ha Giang, Vietnam, continue to experience high infection rates of STHs in 2023. The majority of infections were of light intensity. To address this issue, government efforts should focus on educating the public about STH causes, transmission routes, and negative impacts. Improving personal and environmental hygiene and ensuring access to clean water are essential measures.

Development and validation of a high-throughput qPCR platform for the detection of soil-transmitted helminth infections.

Historically, soil-transmitted helminth (STH) control and prevention strategies have relied on mass drug administration efforts targeting preschool and school-aged children. While these efforts have succeeded in reducing morbidity associated with STH infection, recent modeling efforts have suggested that expanding intervention to treatment of the entire community could achieve transmission interruption in some settings. Testing the feasibility of such an approach requires large-scale clinical trials, such as the DeWorm3 cluster randomized trial. In addition, accurate interpretation of trial outcomes requires diagnostic platforms capable of accurately determining infection prevalence (particularly as infection intensity is reduced) at large population scale and with significant throughput. Here, we describe the development and validation of such a high-throughput molecular testing platform. Through the development, selection, and validation of appropriate controls, we have successfully created and evaluated the performance of a testing platform capable of the semi-automated, high-throughput detection of four species of STH in human stool samples. Comparison of this platform with singleplex reference assays for the detection of these same pathogens has demonstrated comparable performance metrics, with index assay accuracy measuring at or above 99.5% and 98.1% for each target species at the level of the technical replicate and individual extraction respectively. Through the implementation of a rigorous validation program, we have developed a diagnostic platform capable of providing the necessary throughput and performance required to meet the needs of the DeWorm3 cluster randomized trial and other large-scale operational research efforts for STH. Resulting from the rigorous developmental approach taken, the platform we describe here provides the needed confidence in testing outcomes when utilized in conjunction with large-scale efforts such as the DeWorm3 trial. Additionally, the successful development of an evaluation and validation strategy provides a template for the creation of similar diagnostic platforms for other neglected tropical diseases.

Soil-transmitted helminth infections among preschool- and school-aged children in India: A systematic review and meta-analysis of prevalence, risk factors and intervention strategies

Soil-transmitted helminth infections among preschool- and school-aged children in India: A systematic review and meta-analysis of prevalence, risk factors and intervention strategies

Exploring microRNA-Mediated Immune Responses to Soil-Transmitted Helminth and Herpes Simplex Virus Type 2 Co-Infections.

Over the last two decades, the field of microRNA (miRNA) research has grown significantly. MiRNAs are a class of short, single-stranded, non-coding RNAs that regulate gene expression post-transcriptionally. Thereby, miRNAs regulate various essential biological processes including immunity. Dysregulated miRNAs are associated with various infectious and non-infectious diseases. Recently co-infection with soil-transmitted helminths (STHs) and herpes simplex virus type 2 (HSV-2) has become a focus of study. Both pathogens can profoundly influence host immunity, particularly in under-resourced and co-endemic regions. It is well known that STHs induce immunomodulatory responses that have bystander effects on unrelated conditions. Typically, STHs induce T-helper 2 (Th2) and immunomodulatory responses, which may dampen the proinflammatory T-helper 1 (Th1) immune responses triggered by HSV-2. However, the extent to which STH co-infection influences the host immune response to HSV-2 is not well understood. Moreover, little is known about how miRNAs shape the immune response to STH/HSV-2 co-infection. In this article, we explore the potential influence that STH co-infection may have on host immunity to HSV-2. Because STH and HSV-2 infections are widespread and disproportionately affect vulnerable and impoverished countries, it is important to consider how STHs may impact HSV-2 immunity. Specifically, we explore how miRNAs contribute to both helminth and HSV-2 infections and discuss how miRNAs may mediate STH/HSV-2 co-infections. Insight into miRNA-mediated immune responses may further improve our understanding of the potential impact of STH/HSV-2 co-infections.

Potential Interactions Between Soil-Transmitted Helminths and Herpes Simplex Virus Type II: Implications for Sexual and Reproductive Health in Sub-Saharan African.

Sub-Saharan Africa (SSA) bears a disproportionate and overlapping burden of soil-transmitted helminths (STHs) and sexually transmitted viral infections. An estimated 232 million pre-school and school-aged children in SSA are vulnerable to STH infections. Together with this, SSA has a high prevalence of herpes simplex virus type II (HSV-2), the primary cause of genital herpes. Studies have examined the immunological interactions between STHs and human immunodeficiency virus and human papillomavirus during co-infections. However, epidemiological and immunological studies on STH-HSV-2 co-infections are lacking, therefore their impact on sexual and reproductive health is not fully understood. STH-driven Th2 immune responses are known to downregulate Th1/Th17 immune responses. Therefore, during STH-HSV-2 co-infections, STH-driven immune responses may alter host immunity to HSV-2 and HSV-2 pathology. Herein, we provide an overview of the burden of STH and HSV-2 infections in SSA, and host immune responses to STH and HSV-2 infections. Further, we emphasize the relevance and urgent need for (i) focused research into the interactions between these important pathogens, and (ii) integrated approaches to improve the clinical detection and management of STH-HSV-2 co-infections in SSA.

Access barriers and facilitators to implement mass drugs administration strategies for eliminating trachoma and geohelminthiasis in the department of Amazonas, Colombia.

One of the most important pillars of action to achieve the elimination of trachoma and soil-transmitted helminth infections as a public health problem is the mass administration, at regular intervals, of azithromycin and anthielmintics, respectively, to a high proportion of the eligible population in endemic areas. The objective of the study was to identify access barriers and facilitators for achieving coverage goals in the mass drugs administration, azithromycin and albendazole, in the department of Amazonas, Colombia. Implementation research was used, combining three types of qualitative research methodologies to collect information about access barriers and facilitators already described; These were individual and group interviews, focus group discussions and face-to-face intercultural dialogues. We design, validate and apply different instruments with questions adapted to the context and role of the participants, and recorded and transcribed the sessions and analyzed them in qualitative analysis software. We used the Consolidated Framework for Implementation Research (CFIR) to complement the above instrument questions, to guide data analysis, and apply the Consolidated Criteria for Reporting Qualitative Research (COREQ). Records of 159 participants were included; 21 individual and 3 group interviews, 6 focus group discussions and 4 intercultural dialogues were carried out. 21 strong, 30 weak, 6 neutral barriers as well as 5 weak and 11 strong facilitators were identified. 62% of the strong barriers and 40% of the weak ones were concentrated in the "Outer Setting Domain". Only 16 facilitators were identified, 44% in the "Innovation" domain. Multiple political, administrative, geographical, logistical and cultural access barriers, as well as external and internal migration of the population, explain low coverage in mass administration of azithromycin and albendazole. It is necessary to review them individually to implement an improvement plan that also recognizes the identified facilitators.

Descriptive Epidemiology of Soil-Transmitted Helminth Infections in the United States: Using Big Data to Characterize Patients and Analyze Parasitic Disease Trends.

Soil-transmitted helminths (STH) include species responsible for hookworm disease, ascariasis, and trichuriasis. In the United States, STH infections have been greatly reduced with anthelmintic medications and improved hygiene and sanitation, however, cases still regularly occur, but limited epidemiological data exist. We investigated the occurrence of STH infections using big-data analytics of inpatient medical discharge records (1998-2020). Data were obtained from the Healthcare Cost and Utilization Project National Inpatient Sample. We developed an algorithm to extract International Classification of Diseases codes for STH infections from over 805 million records. We report patient characteristics and other epidemiological data. We found a mean of 223 (SD = 70.1) cases annually over the 23 years. Ascariasis (total n = 2599) was the most common, followed by hookworm disease (n = 1809) and trichuriasis (n = 716). Mean annual cases were highest (p < 0.05) in males for hookworm disease (p = 0.0313), but equitable for ascariasis and trichuriasis. Age distributions were skewed towards older patients, with whites and Hispanics most common among records. Chronic anemia and heart disease were common comorbidities. This analysis serves as a case study for using patient record databases as a means of indirect parasitic disease surveillance for population-based studies.

Schistosoma mansoni and soil-transmitted helminth infections among schoolchildren living along the shore of Lake Hawassa, southern Ethiopia

BackgroundSchistosoma mansoni and soil-transmitted helminth (STH) infections are major public health problems in areas with poor sanitation and limited access to water. In Ethiopia, there is limited data available for monitoring the efficacy of interventions aimed at reducing helminth infections. Therefore, we assessed the prevalence of S. mansoni and STH infections, as well as factors associated with this prevalence, among schoolchildren and compared the findings with those of earlier studies. We also evaluated the diagnostic agreement between two parasitological methods.MethodsA cross-sectional study involving 363 schoolchildren from three rural primary schools located along the shore of Lake Hawassa, Sidama Regional State, southern Ethiopia, was conducted in October and November 2023. The schoolchildren were selected using a systematic random sampling technique. Socio-demographic data were collected using pre-structured questionnaires. A single stool sample was collected from each study participant and processed using direct wet mount (DM) microscopy and the formol-ether concentration technique (FECT) to detect helminth ova.ResultsThe overall prevalence of helminths was 59.8%, with 36.6% of participating children having a single infection and 23.1% having multiple infections. Schistosoma mansoni and STHs were present in 33.9% and 38.8% of children, respectively. The STHs included Ascaris lumbricoides (28.9% of children), Trichuris trichiura (10.7%), hookworms (5.2%) and Strongyloides stercoralis (2.8%). Diagnostic agreement between the DM microscopy method and FECT was substantial [kappa (κ) = 0.710] for the detection of Hymenolepis nana and almost perfect (κ = 0.827) for the dection of A. lumbricoides, but only fair for the detection of other detected helminths. Children at Finchawa primary school had a lower prevalence of S. mansoni infection [adjusted odds ratio (AOR) 0.31; 95% confidence interval (CI) 0.13–0.76] than those at St Paul’s Tullo Catholic primary school. STH infections were more common among children who sometimes (vs. always) washed their hands before meals (AOR 1.89; 95% CI 1.01–3.54) and those who regularly played with soil (AOR 2.56; 95% CI 1.47–4.46).ConclusionsThis study showed a reduction in STH infections from a high prevalence in 2015 to a moderate prevalence at the present time, despite a similar moderate prevalence of S. mansoni infection. Thus, it is crucial to intensify deworming interventions to reduce the burden of helminths in the study area. Additionally, there is a need to enhance the capacity of clinical laboratories to perform FECT in Ethiopian clinical settings where DM is often employed to diagnose helminths.Graphical

Human intestinal nematode infections in Sri Lanka: A scoping review.

Sri Lanka, an island located in South Asia, once experienced a notable prevalence of human intestinal nematode infections (HINIs). With the implementation of control programs, infection prevalence was reduced. Detailed information on prevalence, distribution and temporal trends of HINIs is limited. This review aims to explore Sri Lanka's HINI distribution, trends, diagnostics, control and challenges. We reviewed published information on HINIs in Sri Lanka in electronic databases, local journals and grey literature from inception to September 2022. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-Scr), a systematic strategy was used for searching, screening, reviewing and data extraction. The screening was initiated with a review of titles and abstracts using specific keywords, followed by a full-text screening based on predefined eligibility criteria. A total of 105 studies were included in the review, with 28 selected for pooled prevalence analysis. The first nationwide survey in 1924 reported a hookworm infection prevalence of 93.1%. By 2017, soil-transmitted helminth (STH) infection prevalence across the island was 0.97% (ascariasis-0.45%, trichuriasis-0.25%, and hookworm infection-0.29%), and the enterobiasis prevalence between 2003 and 2017 ranged from 0% to 42.5%. Strongyloidiasis had been understudied, with a prevalence of 0.1% to 2%. Over the past two decades, the islandwide pooled HINI prevalence was 13.3%. Within specific demographics, it was 6.96% in the general community, 33.4% in plantation sector, and 11.6% in slum communities. During the colonial period, hookworm infection was the commonest HINI, but ascariasis is now more prevalent. The prevailing data relied solely on microscopy, often utilising single stool smears. Mass deworming programs were widely pursued in the first half of the 20th century, initially targeting antenatal women and schoolchildren, and now focusing on specific community groups. National surveys continue monitoring the three main STH infections. The significant reduction in STH prevalence in the country over the past ten decades highlights the effectiveness of public health interventions, particularly mass deworming programs. Despite the success, STH prevalence disparities persist in vulnerable populations like plantation and slum communities, where hygiene and living conditions continue to pose challenges. Reliance on single stool smear microscopy highlights the need for more sensitive diagnostics to better assess infections. Fluctuating enterobiasis prevalence and limited strongyloidiasis data underscore the importance of continued surveillance and targeted interventions for sustained control and eventual elimination. Sri Lanka's experiences and control measures offer valuable insights for low-income countries in South Asia and beyond, particularly in managing HINIs with limited resources.

Prevalence and risk factors of soil transmitted helminth infections among school-aged children in Garut, Indonesia: Insights from a six-year deworming intervention

Objective: To assess prevalence and factors associated with soil-transmitted helminth (STH) infections among rural school children. Methods: This school-based survey applied a cross-sectional design which included children aged 6-14 years enrolled in 12 elementary schools in Banjarwangi, Garut, West Java Province. Stool and blood samples were collected from 388 randomly selected students to examine the STH infections and anemia status, respectively. Anthropometric assessment was performed to profile nutritional status. A structured questionnaire was employed to collect socio-demographic and school performance data. Multivariable logistic regression models were built to assess the factors associated with STH infections in school children. Results: Among 386 schoolchildren, 9.8% children were positive for one or more STH infections, predominantly Trichuris trichiura (9.0%), with males (n=23), significantly more infected than females (n=13) (5.9% vs. 3.4%, P=0.04). The most infected age group was 6-10 years (n=25, 6.5%). The prevalence of STH infection was significantly higher among students that practicing open defecation (n=22, 5.7%) (P=0.03). The odds risk of STH infections was associated with practicing open defecation (aOR 2.54, 95% CI 1.17-5.53, P=0.02). Conclusions: The findings from this study demonstrate the persistent STH transmission among children underscoring the need for sustained post-MDA intervention strategies in resource-limited settings.

A study protocol for a multi-country cluster randomized controlled trial of the impact of a multi-component One Health strategy to eliminate Opisthorchis viverrini and soil transmitted helminths in the Lower Mekong Basin

BackgroundOpisthorchis viverrini (OV) and soil-transmitted helminths (STH) are two of the most common helminths contributing to the Neglected Tropical Disease (NTDs) burden in the Lower Mekong Basin. Although mass drug administration is the cornerstone of control programs to reduce morbidity caused by these infections, this approach has limitations in preventing re-infections. Elimination requires additional measures such as reservoir host treatment, improved hygiene and health education to reinforce MDA's impact. This study aims to examine the impact of a scalable multi-component One Health Helminth Elimination program in the Lower Mekong Basin (HELM) that combines human praziquantel (PZQ) and albendazole (ALB) treatment with a program that includes the “Magic Glasses” and the “Lawa Model” interventions with health promotion at their core.MethodsThis study will employ a cluster randomized controlled trial (cRCT) in 18 rural communities (with sub-district or villages as cluster units) across Cambodia, Laos and Thailand. The control arm will receive one round of PZQ/ALB treatment, while in the intervention arm, multi-component HELM program will be implemented, which includes PZQ/ALB treatment together with the Magic Glasses and Lawa Model interventions. OV and STH infections levels will be evaluated in individuals aged 5–75 years at baseline and will be repeated at follow-up (12 months after the HELM intervention), using modified formalin ethyl-acetate concentration technique and quantitative PCR. The primary outcome of the study will be cumulative incidence of human OV and STH infections. Outcomes between the study arms will be compared using generalized linear mixed models, accounting for clustering.DiscussionEvidence from this trial will quantify the impact of a multi-component One Health control strategy in interrupting Ov and STH infections in the Lower Mekong Basin.Trial registrationAustralian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12622000353796. Prospectively registered 28 February 2022.

Interplay Between Helminth Infections, Malnutrition, and Gut Microbiota in Children and Mothers from Pemba, Tanzania: Potential of Microbiota-Directed Interventions.

Despite efforts within the framework of the Sustainable Development Goal to end malnutrition by 2030, malnutrition and soil-transmitted helminth infections persist in sub-Saharan Africa. A significant barrier to success is the inadequate understanding of effective intervention methods. Most research on the gut microbiota's role in health has been conducted in developed countries, leaving a critical gap in knowledge regarding low-income populations. This study addresses this gap by expanding research on the gut microbiota of underprivileged populations to help tackle these public health challenges. We employed 16S rDNA sequencing to assess the bacterial gut microbiota composition of 60 children (mean age: 26.63 ± 6.36 months) and their 58 mothers (mean age: 30.03 ± 6.31 years) in Pemba, with a focus on helminth infection and nutritional status. Our differential abundance analysis identified bacterial taxa that were significantly negatively associated with both helminth infections and malnutrition, highlighting the potential for microbiota-directed interventions to address these health issues simultaneously. Notably, we identified Akkermansia, Blautia, Dorea, and Odoribacter as promising probiotic candidates for such interventions. In stunted children, positive co-occurrences were observed between Lactobacillus, Prevotella, and Bacteroides, while Escherichia/Shigella displayed negative co-abundance relationships with short-chain fatty acid (SCFA) producers in the gut microbiota. These findings suggest that administering Lactobacillus and SCFA-producing probiotics to children may foster the growth of beneficial bacteria like Prevotella and Bacteroides while reducing the relative abundance of Escherichia/Shigella, potentially enhancing overall health. This study underscores the importance of microbiota-directed interventions in children and women of reproductive age as promising strategies, alongside established approaches, for combating helminth infections and malnutrition in vulnerable populations.

Schistosoma mansoni and soil-transmitted helminthic infections and associated factors among pregnant women in Jimma Town, Southwest Ethiopia

BackgroundSchistosomiasis and soil-transmitted helminth (STH) infections occurring during pregnancy may pose adverse health consequences to the mother and the developing baby. This study aims to determine the prevalence of Schistosoma mansoni and STHs, and their association with adverse birth outcomes among pregnant women in Jimma Town.MethodsA cross-sectional study involving 314 pregnant women was conducted in Jimma Town, Southwest Ethiopia. The pregnant women were recruited from selected public health facilities during their antenatal care (ANC) visits from August to December 2021. Data on demographic characteristics and factors associated with S. mansoni and STH infections were collected using a pretested questionnaire. Moreover, during the third trimester, stool specimen of each pregnant woman was examined using Kato-Katz technique, and hemoglobin was measured using a HemoCue analyzer. Data on adverse birth outcomes were collected during delivery. Data were analyzed using STATA-MP_12 (StataCorp., TX, USA).ResultsThe overall prevalence of intestinal helminthic infections was 26.1%. Soil-transmitted helminths and S. mansoni were detected in 20.4% (95%CI: 15.9–24.8) and 5.7% (95%CI: 3.2–8.3) of the pregnant women, respectively. The magnitude of low birth weight was 6.4%, higher in those with late-term delivery and maternal anemia (p < 0.05). Maternal anemia was also associated with post-partum bleeding (p < 0.05). Pregnant women who carry out laundry activities in the river were significantly more infected by S. mansoni (AOR 10.7, 95% CI: 2.2–51.9).ConclusionsThis study sheds light on the burden of maternal STH and S. mansoni infections in Jimma Town. A quarter of the pregnant women were infected with STHs and S. mansoni. It is recommended that pregnant women in the area avoid washing clothes in the river to reduce the risk of S. mansoni infection. Screening for intestinal parasitic infections should be conducted for pregnant women living in endemic areas during their ANC follow-up.

HIGH PREVALENCE OF PARASITES WITH ZOONOTIC POTENTIAL IN SOILS OF PUBLIC SQUARES AND PARKS IN THE METROPOLITAN REGION OF RECIFE-PE, BRAZIL

Soil-transmitted helminth infections are the most widespread neglected tropical diseases in the world. The soil of public areas such as squares and parks represents a transmission risk for humans and other animals. Thus, the aim of the present study was to assess the frequency of soil-isolated parasites in squares and public parks in the city of Recife, Pernambuco - Brazil. Soil samples were collected from six squares or parks located in the metropolitan region of the municipality. The material analysis was performed using the Rugai technique adapted for soil, allowing the identification of evolutionary stages of parasites through optical microscopy and taxonomic classification. All soil samples collected showed contamination by at least two genera of parasites, with up to six different parasites highlighted in Parques Dona Lindu, 13 de Maio, and Praça do Derby. Larvae of Ancylostoma sp and Strongyloides sp. were found in all collection sites, with a frequency of 100% in Parques Dona Lindu and Lagoa do Araçá, and 90% in Parque 13 de Maio. In Parque da Jaqueira, only larvae in the evolutionary stage of Ancylostoma sp. were identified, with a frequency of 50%, and of Strongyloides sp., with 70%. Eggs of A. lumbricoides were detected only in the soil of Praça do Derby, with a frequency of 10%. The data obtained from the studied sites showed high soil contamination by geohelminths, highlighting their relevance for both public health and veterinary and human medicine.

A comparison of the diagnostic capability of Kato-Katz and real-time PCR for the assessment of treatment efficacy of ivermectin and albendazole combination against T. trichiura infections.

Trichuris trichiura is humans' second most prevalent soil-transmitted helminth (STH) infection after Ascaris lumbricoides, affecting approximately 460 million people worldwide. Despite its sub-optimal sensitivity, especially in low prevalence and infection intensity settings, the modified Kato-Katz (K-K) is still recommended as a diagnostic method by the World Health organization (WHO) guidelines. Within a randomized clinical trial (RCT) comprising four treatment arms with two different anthelmintics, the present study reports an important secondary research objective to determine the diagnostic agreement between K-K and real-time PCR evaluating treatment efficacy against T. trichiura. The parasitological results were analyzed, including cure rates (CR) of a subgroup of 94 participants positive at baseline for T. trichiura eggs for both techniques. The single-dose albendazole (ALB) arm resulted in significantly lower CRs than experimental arms of albendazole/ivermectin (ALB/IVM) combinations. The overall diagnostic agreement between both techniques was 88.7% [κ = 0.8 (P<0.001)]. Concordance between eggs per gram and Ct values was moderate, with the discordance source likely stemming from lighter infection intensities. These findings indicate that real-time PCR is a suitable alternative for CR estimation in helminthiasis clinical trials. It also highlights the need to identify the most accurate diagnostic tools for RCTs, that would benefit from guiding principles to achieve harmonization across studies and are not necessarily the same as those used for epidemiological surveys. Clinical Trials.gov (NCT04041453).

A scoping review of transmission models for soil-transmitted helminth infections to underpin the development of a transmission model for Strongyloides stercoralis.

Soil-transmitted helminth (STH) infections afflict people worldwide, especially in tropical and subtropical regions. Strongyloides stercoralis is distinctive from other STH nematodes by its complex life cycle features of autoinfection, parthenogenesis, and environmental reproduction. This scoping review aims to identify the structures, features, and techniques employed in existing STH models, emphasizing their potential application in describing S. stercoralis infection dynamics. A comprehensive search was conducted in the Medline, Embase, and Scopus databases for studies published until 14 June 2024. A total of 47 studies presenting a new model or novel adaptation of an existing model to human STH infection transmission were identified: only one described S. stercoralis transmission in humans. The identified models were predominantly deterministic and focused on the dynamics of mean worm load within hosts and the infectiousness of the environmental reservoir. One model addressed transmission in multi-host scenarios, as not all STH transmission cycles involve multiple hosts. Models were frequently used to simulate the effectiveness of mass drug administration, including drug efficacy and treatment coverage, while water, sanitation, and hygiene (WASH), health education, and vaccination were less explored. Given the limitation of individual-level data, compartmental models may be a reasonable starting point for S. stercoralis transmission. For a comprehensive understanding, incorporating parasite life cycle features into the model, exploring multi-host dynamics, including a diverse range of host heterogeneities, and assessing the impact of climatic factors like rainfall and land surface temperature on parasite survival in the environment may be beneficial, especially in settings where their importance is notable.

Deep-amplicon sequencing of the complete beta-tubulin gene in Trichuris trichiura before and after albendazole treatment

Concerns about the emergence of benzimidazole resistance in soil-transmitted helminths (STH) infections, particularly against Trichuris trichiura, have arisen. Previous studies of veterinary nematodes have linked benzimidazole resistance to single-nucleotide polymorphisms (SNPs) at three specific codons in the beta-tubulin gene, but similar associations in STH have not been consistently observed. In this work, we screened the complete beta-tubulin gene previously linked to benzimidazole resistance in T. trichiura by deep-amplicon sequencing to identify genetic variants and associate levels of diversity with drug response to albendazole. We used 99 DNA samples extracted from T. trichiura pooled eggs, previously semi-purified from human stool samples collected in Manhiça district, Mozambique. We obtained a set of 39 amplicons of the complete gene by subjecting the pooled eggs to long-read PCR and subsequently sequencing them. Of those amplicons, 22 and 17 were obtained from stool samples collected before, and 21 days after albendazole treatment, respectively. We observed genetic variation across the whole gene sequence, in both exons and introns; however, none were associated with the previously proposed resistance-associated SNPs, and none were predicted to significantly affect protein function. No significant differences in genetic diversity were observed between pre- and post-treatment samples. Using publicly available genome-wide data, we also analysed a second beta-tubulin isotype in the T. trichiura genome. We focused on detecting the canonical SNPs and assessing for signatures of genetic selection around this second isotype gene. This analysis did not reveal evidence supporting this second isotype's role in anthelmintic resistance. Despite the limitations of our study, such as a small sample size, particularly paired pre- and post-treatment samples (n = 6), or a restricted geographical area, we found no evidence linking either of the two beta-tubulin genes to benzimidazole resistance in T. trichiura, suggesting that genetic markers of drug resistance likely exist outside the beta-tubulin genes.

Study on Single and Combination of Galangal, Turmeric, and Ginger Ethanol Extracts as Anthelmintic

Soil-Transmitted Helminth infection (STH) such as ascariasis, has become one of the most persistent parasitic diseases in most developing countries, including Indonesia. Galangal, turmeric, and ginger plants are known to provide various of pharmacologically active substances which commonly used as antibacterial, aphrodisiac, and antiparasitic. This research was aimed to study the anthelmintic activity of ethanol extract of ginger, turmeric, galangal in single extract as well as their combination against Ascaris suum Goeze as a model. The anthelmintic activity was analyzed by determining the profile of time of paralysis (TOP), time of death (TOD), and the IC50­ of the inhibition activity from single extracts and extract combinations as well as the combination index (CI). The results showed that galangal, turmeric, and ginger ethanol extract have anthelmintic activity with IC50 7.66, 22, and 13,14 mg/mL, respectively. Meanwhile, the IC50 values for the extract combination of galangal with turmeric (KL), galangal with ginger (JL), and turmeric with ginger (JK) were 10.22; 3.92; and 34.93 mg/mL, respectively. The synergistic combination properties were shown by combination of galangal with turmeric extracts and galangal with ginger extracts with the combination index (CI) 0,67 and 0,38, respectively.