Global numbers of infection and disease burden of soil transmitted helminth infections in 2010

An Ascaris lumbricoides infection diagnosed by colonoscopy: A case report and a brief literature review

BACKGROUND

Ascaris lumbricoides is a nematode that parasitizes the human gastrointestinal tract, and it is the cause of the most common helminthic infections worldwide. It predominates in areas of poor sanitation. Early diagnosis of this intestinal infection is pivotal to avoid its severe and lethal complications such as gut obstruction, volvulus, and perforation.

CASE REPORT

A 61-year-old Caucasian female was admitted to the Operational Unit of Gastrointestinal Endoscopic Surgery with abdominal pain, in combination with nausea and vomiting for 2 months. The woman underwent a colonoscopy and surprisingly A. lumbricoides was highlighted. Diagnosis of A. lumbricoides infections is based on the microscopic detection of eggs in stool, thus, patient fecal samples collected were examined by microscopy-based methods, but no eggs were found. Previously, the patient was treated to eradicate H. pylori, using omeprazole, a common proton pump inhibitor.

DISCUSSION

Here, we supposed that previous therapy has mitigated the parasite infection severity. In our patient was identified A. lumbricoides, although she came from a medium socio-economic status family and despite, she reported to have never travelled in tropical and subtropical areas. This report highlights the importance of the awareness of ascariasis and that its preventive measures should be included in all health education programs.

Harnessing Non-standard Nucleic Acids for Highly Sensitive Icosaplex (20-Plex) Detection of Microbial Threats for Environmental Surveillance

Environmental surveillance and clinical diagnostics heavily rely on the polymerase chain reaction (PCR) for target detection. A growing list of microbial threats warrants new PCR-based detection methods that are highly sensitive, specific, and multiplexable. Here, we introduce a PCR-based icosaplex (20-plex) assay for detecting 18 enteropathogen and two antimicrobial resistance genes. This multiplexed PCR assay leverages the self-avoiding molecular recognition system (SAMRS) to avoid primer dimer formation, the artificially expanded genetic information system (AEGIS) for amplification specificity, and next-generation sequencing for amplicon identification. Using parallelized multitarget TaqMan Array Cards (TAC) to benchmark performance of the 20-plex assay on wastewater, soil, and human stool samples, we found 90% agreement on positive calls and 89% agreement on negative calls. Additionally, we show how long-read and short-read sequencing information from the 20-plex can be used to further classify allelic variants of genes and distinguish subspecies. The strategy presented offers sensitive, affordable, and robust multiplex detection that can be used to support efforts in wastewater-based epidemiology, environmental monitoring, and human/animal diagnostics.

IL-4 induces CD22 expression to restrain the effector program of virtual memory T cells

Parasitic helminths induce the production of interleukin-4 (IL-4), which causes the expansion of virtual memory CD8+ T cells (TVM cells), a cell subset that contributes to the control of coinfection with intracellular pathogens. However, the mechanisms regulating IL-4-dependent TVM cell activation and expansion remain ill defined. Here, we used single-cell RNA sequencing of CD8+ T cells to identify pathways that control IL-4-dependent TVM cell responses. Gene signature analysis of CD8+ T cells identified a cell cluster marked by CD22, a canonical regulator of B cell activation, as a selective surface marker of IL-4-induced TVM cells. CD22+ TVM cells were enriched for interferon-γ and granzyme A and retained a diverse TCR repertoire while enriched in self-reactive CDR3 sequences. CD22 intrinsically regulated the IL-4-induced CD8+ T cell effector program, resulting in reduced responsiveness of CD22+ TVM cells and regulatory functions to infection and inflammation. Thus, helminth-induced IL-4 drives the expansion and activation of TVM cells that is counterinhibited by CD22.

Hookworm genes encoding intestinal excreted-secreted proteins are transcriptionally upregulated in response to the host's immune system

Hookworms are intestinal parasitic nematodes that chronically infect ∼500 million people, with reinfection common even after clearance by drugs. How infecting hookworms successfully overcome host protective mechanisms is unclear, but it may involve hookworm proteins that digest host tissues, or counteract the host's immune system, or both. To find such proteins in the zoonotic hookworm Ancylostoma ceylanicum , we identified hookworm genes encoding excreted-secreted (ES) proteins, hookworm genes preferentially expressed in the hookworm intestine, and hookworm genes whose transcription is stimulated by the host immune system. We collected ES proteins from adult hookworms harvested from hamsters; mass spectrometry identified 565 A. ceylanicum genes encoding ES proteins. We also used RNA-seq to identify A. ceylanicum genes expressed both in young adults (12 days post-infection) and in intestinal and non-intestinal tissues dissected from mature adults (19 days post-infection), with hamster hosts that either had normal immune systems or were immunosuppressed by dexamethasone. In adult A. ceylanicum , we observed 1,670 and 1,196 genes with intestine- and non-intestine-biased expression, respectively. Comparing hookworm gene activity in normal versus immunosuppressed hosts, we observed almost no changes of gene activity in 12-day young adults or non-intestinal 19-day adult tissues. However, in intestinal 19-day adult tissues, we observed 1,951 positively immunoregulated genes (upregulated at least two-fold in normal hosts versus immunosuppressed hosts), and 137 genes that were negatively immunoregulated. Thus, immunoregulation was observed primarily in mature adult hookworm intestine directly exposed to host blood; it may include hookworm genes activated in response to the host immune system in order to neutralize the host immune system. We observed 153 ES genes showing positive immunoregulation in 19-day adult intestine; of these genes, 69 had ES gene homologs in the closely related hookworm Ancylostoma caninum , 24 in the human hookworm Necator americanus , and 24 in the more distantly related strongylid parasite Haemonchus contortus . Such a mixture of rapidly evolving and conserved genes could comprise virulence factors enabling infection, provide new targets for drugs or vaccines against hookworm, and aid in developing therapies for autoimmune diseases.

Hybrid and/or mixed infection by pig and human Ascaris in a Guarani indigenous village in southern Brazil

BACKGROUND

Ascaris lumbricoides and Ascaris suum are nematode parasites that infect millions of people and pigs worldwide, respectively. Reports of cross-infection and hybridization between the two species has stimulated molecular epidemiological studies of the Ascaris genus. In this study, we evaluated the dynamics of Ascaris transmission between Guarani indigenous schoolchildren, pigs, and the environment of a village in the state of Paraná, southern Brazil.

METHODOLOGY/PRINCIPAL FINDINGS

Parasitological and molecular analyses of fecal samples from humans and pigs, and soil samples from the village were carried out. Eggs of Ascaris spp. were observed in 8.4% (7/83) of human samples, 44.4% (8/18) of pig samples, and 8.9% (6/68) of soil samples. PCR amplification of the ITS-1 locus of the rDNA gene in samples that were positive in the parasitological examination revealed mixed infection and/or hybrids of the two species, A. lumbricoides and A. suum, in human and swine hosts. The soil, which was contaminated by both human and swine feces, also contained eggs of the two Ascaris species and hybrids, thus constituting a source of Ascaris infection for both hosts. DNA from A. lumbricoides and A. suum, individually, was detected in samples from humans and pigs, respectively, and the soil, while DNA from hybrid and/or Ascaris spp. was detected in samples from both hosts and the soil.

CONCLUSIONS/SIGNIFICANCE

The results of this study confirm the necessity of a One Health approach with the correct disposal of both human and animal feces to control the spread of human and swine ascariasis.

Performance of real-time polymerase chain reaction and Kato-Katz for diagnosing soil-transmitted helminth infections and evaluating treatment efficacy of emodepside in randomized controlled trials

BACKGROUND

The World Health Organization recommends the use of the microscopy-based Kato-Katz thick smear for diagnosing soil-transmitted helminth (STH) infections. Despite its simplicity and cost-effectiveness, the Kato-Katz method faces challenges, including reader subjectivity and reduced sensitivity. Real-time polymerase chain reaction (qPCR) technology offers standardized readouts and higher sensitivity, making it suitable for STH diagnosis and monitoring the treatment efficacy of emodepside within the framework of randomized controlled trials.

METHODOLOGY/PRINCIPAL FINDINGS

We evaluated the performance of Kato-Katz versus qPCR for assessing treatment efficacy in terms of cure rates, of single doses of 5, 10, 15, 20, 25 and 30 mg of emodepside compared to 400 mg albendazole. Spearman's rank correlation coefficient examined the correlation between STH eggs per gram in stool samples and qPCR Ct values. Diagnostic sensitivity of qPCR was calculated using a Bayesian latent class modelling approach with data from Ascaris lumbricoides infections. Agreement between Kato-Katz and qPCR at baseline was 93.57% for Trichuris trichiura, and 73.49% for both hookworm and A. lumbricoides. For the latter helminth qPCR demonstrated higher sensitivity (85.00% vs. 47.70%) and slightly lower specificity (93.40% vs. 99.40%) compared to Kato-Katz. We observed a fair to moderate agreement with negative correlation between Ct values and Kato-Katz egg counts. Treatment efficacy, as assessed by qPCR, was lower for all doses of emodepside and albendazole compared to Kato-Katz. Nonetheless, emodepside demonstrated higher cure rates against T. trichiura and A. lumbricoides infections compared to albendazole.

CONCLUSION/ SIGNIFICANCE

Our study confirmed that qPCR is a sensitive diagnostic method for diagnosing STH infections compared to Kato-Katz and serves as a valuable tool for determining treatment efficacy in clinical trials. Furthermore, qPCR confirmed the better treatment efficacy of emodepside compared to albendazole, despite indicating lower cure rates than Kato-Katz.

Multi-dimensional analysis of B cells reveals the expansion of memory and regulatory B-cell clusters in humans living in rural tropical areas

B-cells play a critical role in the formation of immune responses against pathogens by acting as antigen-presenting cells, by modulating immune responses, and by generating immune memory and antibody responses. Here, we studied B-cell subset distributions between regions with higher and lower microbial exposure, i.e. by comparing peripheral blood B-cells from people living in Indonesia or Ghana to those from healthy Dutch residents using a 36-marker mass cytometry panel. By applying an unbiased multidimensional approach, we observed differences in the balance between the naïve and memory compartments, with higher CD11c+ and double negative (DN-IgDnegCD27neg) memory (M)B-cells in individuals from rural tropical areas, and conversely lower naïve B-cells compared to residents from an area with less pathogen exposure. Furthermore, characterization of total B-cell populations, CD11c+, DN, and Breg cells showed the emergence of specific memory clusters in individuals living in rural tropical areas. Some of these differences were more pronounced in children compared to adults and suggest that a higher microbial exposure accelerates memory B-cell formation, which "normalizes" with age.

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.

High-Throughput Screening of More Than 30,000 Compounds for Anthelmintics against Gastrointestinal Nematode Parasites

Gastrointestinal nematodes (GINs) are among the most common parasites of humans, livestock, and companion animals. GIN parasites infect 1-2 billion people worldwide, significantly impacting hundreds of millions of children, pregnant women, and adult workers, thereby perpetuating poverty. Two benzimidazoles with suboptimal efficacy are currently used to treat GINs in humans as part of mass drug administrations, with many instances of lower-than-expected or poor efficacy and possible resistance. Thus, new anthelmintics are urgently needed. However, screening methods for new anthelmintics using human GINs typically have low throughput. Here, using our novel screening pipeline that starts with human hookworms, we screened 30,238 unique small molecules from a wide range of compound libraries, including ones with generic diversity, repurposed drugs, natural derivatives, known mechanisms of action, as well as multiple target-focused libraries (e.g., targeting kinases, GPCRs, and neuronal proteins). We identified 55 compounds with broad-spectrum activity against adult stages of two evolutionary divergent GINs, hookworms (Ancylostoma ceylanicum) and whipworms (Trichuris muris). Based on known databases, the targets of these 55 compounds were predicted in nematode parasites. One novel scaffold from the diversity set library, F0317-0202, showed good activity (high motility inhibition) against both GINs. To better understand this novel scaffold's structure-activity relationships (SAR), we screened 28 analogs and created SAR models highlighting chemical and functional groups required for broad-spectrum activity. These studies validate our new and efficient screening pipeline at the level of tens of thousands of compounds and provide an important set of new GIN-active compounds for developing novel and broadly active anthelmintics.

Using ESPEN data for evidence-based control of neglected tropical diseases in sub-Saharan Africa: A comprehensive model-based geostatistical analysis of soil-transmitted helminths

BACKGROUND

The Expanded Special Project for the Elimination of Neglected Tropical Diseases (ESPEN) was launched in 2019 by the World Health Organization and African nations to combat Neglected Tropical Diseases (NTDs), including Soil-transmitted helminths (STH), which still affect over 1.5 billion people globally. In this study, we present a comprehensive geostatistical analysis of publicly available STH survey data from ESPEN to delineate inter-country disparities in STH prevalence and its environmental drivers while highlighting the strengths and limitations that arise from the use of the ESPEN data. To achieve this, we also propose the use of calibration validation methods to assess the suitability of geostatistical models for disease mapping at the national scale.

METHODS

We analysed the most recent survey data with at least 50 geo-referenced observations, and modelled each STH species data (hookworm, roundworm, whipworm) separately. Binomial geostatistical models were developed for each country, exploring associations between STH and environmental covariates, and were validated using the non-randomized probability integral transform. We produced pixel-, subnational-, and country-level prevalence maps for successfully calibrated countries. All the results were made publicly available through an R Shiny application.

RESULTS

Among 35 countries with STH data that met our inclusion criteria, the reported data years ranged from 2004 to 2018. Models from 25 countries were found to be well-calibrated. Spatial patterns exhibited significant variation in STH species distribution and heterogeneity in spatial correlation scale (1.14 km to 3,027.44 km) and residual spatial variation variance across countries.

CONCLUSION

This study highlights the utility of ESPEN data in assessing spatial variations in STH prevalence across countries using model-based geostatistics. Despite the challenges posed by data sparsity which limit the application of geostatistical models, the insights gained remain crucial for directing focused interventions and shaping future STH assessment strategies within national control programs.

Multimodality imaging of pediatric ascariasis

Ascariasis is a prevalent intestinal helminthic infection caused by Ascaris lumbricoides, commonly known as roundworm. While the disease may remain asymptomatic when the parasites are confined to the intestinal lumen of the small bowel, symptoms and complications can arise when the helminths invade the biliary tree or pancreatic ducts. In cases of severe infection, a mass of roundworms can lead to intestinal complications, such as bowel obstruction. The morphological identification of Ascaris by multimodality imaging techniques plays a crucial role in the diagnosis, as well as in the monitoring and prevention of complications.

Trichuriasis in Human Patients from Côte d'Ivoire Caused by Novel Trichuris incognita Species with Low Sensitivity to Albendazole/Ivermectin Combination Treatment

Albendazole/ivermectin combination therapy is a promising alternative to benzimidazole monotherapy alone for Trichuris trichiura control. We used fecal DNA metabarcoding to genetically characterize Trichuris spp. populations in patient samples from Côte d'Ivoire showing lower (egg reduction rate <70%) albendazole/ivermectin sensitivity than those from Laos and Tanzania (egg reduction rates >98%). Internal transcribed spacer (ITS) 1 and ITS2 metabarcoding revealed the entire detected Côte d'Ivoire Trichuris population was phylogenetically distinct from T. trichiura found in Laos and Tanzania and was more closely related to T. suis. Mitochondrial genome sequencing of 8 adult Trichuris worms from Côte d'Ivoire confirmed their species-level differentiation. Sequences from human patients in Cameroon and Uganda and 3 captive nonhuman primates suggest this novel species, T. incognita, is distributed beyond Côte d'Ivoire and has zoonotic potential. Continued surveillance by using fecal DNA metabarcoding will be needed to determine Trichuris spp. geographic distribution and control strategies.

Asymptomatic Malaria Infection and Hidden Parasitic Burden in Gabonese Schoolchildren: Unveiling Silent Co-Infections in Rural and Urban Settings

This study aimed to determine the prevalence of co-infection with malaria and intestinal parasites and assess its association with anemia in school-aged children from rural and urban settlements in Gabon. This cross-sectional study involved afebrile school children recruited at schools between May and June 2021. Blood and stool samples were collected from participants whose parents or legal guardians provided informed consent to participate in the study. Hemoglobin concentration (Hb) was measured using a HemoCue photometer (HemoCue 201, HemoCue, Angelholm, Sweden). Giemsa-stained blood films were examined to detect malaria parasites and any filarial infections, while the merthiolate-iodine concentration (MIC) method was used to identify intestinal parasitic infections (IPI). A total of four hundred and seventy (470) school-aged children were successfully enrolled in this study. The observed prevalence values were as follows: malaria infection at 69.6%, IPIs at 19.1%, filaria at 5.1%, Schistosoma infection at 15.0%, and anemia at 29.0%. Co-infections of malaria with IPIs, filaria, and Schistosoma were present in 12.3%, 4.7%, and 6.6% of the children, respectively. Malaria and filaria infections were associated with residing in Lastourville city (p < 0.05) and were also correlated with age (p < 0.05), whereas IPIs were associated with male gender and living in the city of Lastourville. Anemia was linked to malaria infection (p < 0.05) and was more prevalent among children living in rural areas. The findings of this study indicate that malaria, IPIs, and Schistosoma infections continue to pose a significant public health problem in the study area, even though only malaria infection appeared to be associated with anemia. Nevertheless, these results highlight the need for implementing control measures to reduce the prevalence of malaria, IPIs, filaria, and Schistosoma, particularly in Lastourville.

Knowledge, attitudes and preventive practices towards soil-transmitted helminthiases among teachers in schools implementing the home-grown school feeding program in Enugu Metropolis, Enugu State, Nigeria

BACKGROUND

Soil-transmitted helminthiases (STHs) are prevalent in low- and middle-income countries, impacting school-aged children significantly. Teachers, integral to STH control through the Home-Grown School Feeding Program (HGSFP), need adequate knowledge, attitudes, and preventive practices (KAP) for successful STH prevention. However, there is limited research on teacher KAP regarding STH in Enugu State, particularly concerning its endemic nature. This study assessed the KAP of primary school teachers involved in the HGSFP in Enugu Metropolis, Nigeria, aiming to inform targeted interventions for STH control.

METHODS

This analytical cross-sectional study, conducted from September 2023 to January 2024, involved 108 primary school teachers from nine randomly selected schools in Enugu Metropolis, Nigeria. Data were collected using a structured questionnaire, which had undergone rigorous validation and reliability testing. Descriptive statistics, chi-square tests, and logistic regression analyses were performed.

RESULTS

While 69.4% of the teachers demonstrated good knowledge and 77.8% had good attitudes towards STH, only 27.8% reported good preventive practices. Younger teachers (25-34 years) exhibited better knowledge (94.1% vs. 56.4%, p = 0.018) and practices (52.9% vs. 30.8%, p = 0.015) compared to their older colleagues (≥ 45 years). Years of teaching experience significantly influenced attitudes, with teachers having 11-20 years of experience exhibiting the most favorable attitudes (95.8%, p = 0.030). Age was a significant predictor of good practice with teachers aged 35-44 years being 7.72 times more likely to report good practices than those ≥ 45 years (AOR: 7.72, 95% CI: 5.66-35.9).

CONCLUSIONS

The study reveals a critical disconnect between high levels of knowledge and positive attitudes towards STH among teachers and their lower levels of good preventive practices. This highlights that positive attitudes alone may not be sufficient for effective implementation of preventive measures. This underscores the need for targeted interventions, particularly tailored training for older and more experienced teachers. Incorporating evidence-based behavior change strategies, addressing potential barriers to practice implementation, and improving access to resources are crucial for enhancing STH prevention efforts within the HGSFP and safeguarding the health of teachers and students.

The impact of an integrated intervention program combining drug therapy with water, sanitation, and hygiene (WASH) education on reinfection with intestinal parasitic infections among the Karen hill tribe in northern Thailand

BACKGROUND

Intestinal parasitic infections (IPIs) are a major health problem among the Karen hill tribe in Thailand. This study aimed to evaluate the effect of an integrated intervention program of drug therapy combined with water, sanitation, and hygiene (WASH) education on reinfection with IPIs among the Karen hill tribe in an endemic area of northern Thailand.

METHODS

A quasi-experimental study was conducted in two Karen villages, involving 691 residents, in Omkoi District, Chiang Mai Province; one village was designated as the intervention group and the other as the control group. Baseline information was collected regarding the infections and participants' knowledge, attitudes, and practices (KAP) related to prevention and control of IPIs. Detection of benzimidazole resistance linked to the beta-tubulin gene mutation in soil-transmitted helminths (STH) was performed using polymerase chain reaction (PCR) amplification and DNA sequencing. Mass drug administration (MDA) with albendazole was applied to both groups. The intervention group received WASH education, whereas the control group did not. Follow-up assessments were conducted at 3 and 6 months.

RESULTS

Baseline data revealed a 36.0% (123/342) prevalence of IPIs in the intervention group and 36.8% (96/261) in the control group. The most common helminth and pathogenic protozoan were Trichuris trichiura and Giardia lamblia, respectively. No non-synonymous mutations in the beta-tubulin gene were found. Post-intervention at 3-month and 6-month follow-ups revealed that the prevalence of IPIs in the intervention group was significantly decreased to 23.6% (P = 0.002) and 23.1% (P = 0.002), and the prevalence of pathogenic IPIs was reduced from 9.4% to 3.9% (P = 0.013) and 2.4% (P = 0.002), respectively. In contrast, no significant changes in the prevalence of IPIs were observed in the control group. The intervention group showed significant improvements in KAP scores, which were significantly higher than those in the control group.

CONCLUSIONS

MDA alone is not effective for controlling IPIs among the Karen people due to rapid reinfection related to behavioral factors and socioeconomic conditions. We demonstrated for the first time that integration of WASH education increased KAP scores and consequently significantly reduced IPI reinfection among the Karen hill tribe in northern Thailand.

Assessing the Burden of Neglected Tropical Diseases in Low-Income Communities: Challenges and Solutions

Neglected tropical diseases (NTDs) represent a group of chronic and debilitating infections that affect more than one billion people, predominantly in low-income communities with limited health infrastructure. This paper analyzes the factors that perpetuate the burden of NTDs, highlighting how poor health infrastructure, unfavorable socioeconomic conditions and lack of therapeutic resources exacerbate their impact. The effectiveness of current interventions, such as mass drug administration (MDA) programs and improved sanitation, in reducing disease prevalence is examined. In addition, the role of climate change, which alters transmission dynamics and expands affected territories, is discussed as an emerging challenge. The analysis suggests that integrated, multisectoral approaches, including health education and infrastructure interventions, are essential to breaking the cycle of poverty and disease. Although international programs have marked significant progress, achieving elimination targets by 2030 requires sustained commitment, innovation, and increased research capacity in endemic countries.

Hookworm infection and its determinants among schoolchildren in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Hookworm infection is a common problem among schoolchildren and mothers in tropical and subtropical countries, causing cognitive impairment, growth retardation in children and anaemia, low birth weight, preterm birth, and intrauterine growth delay in susceptible mothers. Since schoolchildren generally have a higher prevalence due to behavioral and hygiene-related factors, our systematic review and meta-analysis aimed to determine the prevalence and risk factors for Hookworm infection among schoolchildren in Ethiopia.

METHODS

Relevant studies were retrieved from several search databases. The data were extracted via a standard data extraction format, and STATA version 11 was utilized for the analysis. Funnel plots and Egger's regression tests were used to evaluate publication bias, whereas the I2 test was used to determine heterogeneity. A random effects model meta-analysis was conducted to determine the pooled prevalence and associated factors of Hookworm infection among schoolchildren.

RESULTS

In this review, 48 studies with 43,285 participants were included. The pooled prevalence of Hookworm among schoolchildren was 13.01% (95% CI: 10.52, 15.51). Hookworm infection was significantly associated with the inability to use protective footwear (OR = 5.90, 95% CI: 2.86, 12.18) and the inability to use latrines (OR = 3.04, 95% CI: 1.77, 5.23). Subgroup analysis by diagnostic methods revealed that the highest prevalence of Hookworm was found to be 28.50% (95% CI: 24.09, 32.91) using combinations of Kato-Katz, McMaster, and spontaneous tube sedimentation techniques.

CONCLUSION

Our study revealed that a significant prevalence of schoolchildren were affected by Hookworms, with substantial regional variations. This suggests that there is a need for better control measures such as improving hygiene, sanitation, and protective measures such as footwear. In addition, a combination of one or more diagnostic methods should be employed for better detection of parasites. This systematic review and meta-analysis have been registered in PROSPERO with reference number CRD42024558542.

Human intestinal nematode infections in Sri Lanka: A scoping review

BACKGROUND

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.

METHODOLOGY

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.

PRINCIPAL FINDINGS

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.

CONCLUSIONS

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.

Incidence and Pathological Analysis of Parasitic Infections in Underserved Communities

Background

Parasitic infections remain a significant public health concern, particularly in underserved communities where access to healthcare and sanitation is limited. This study aims to investigate the incidence and pathological characteristics of parasitic infections in such communities, providing insights into the prevalence and impact of these infections on public health.

Materials and Methods

A cross-sectional study was conducted in underserved communities over a period of one year. A total of 500 participants were randomly selected and screened for parasitic infections through stool and blood samples. The samples were analyzed using microscopy and polymerase chain reaction (PCR) techniques to identify and quantify parasitic species. Pathological examinations were performed to assess the impact of infections on host tissues.

Results

The incidence of parasitic infections was found to be 35% among the study population. The most common parasites identified were Ascaris lumbricoides (40%), Giardia lamblia (25%), and Entamoeba histolytica (20%). Pathological analysis revealed that Ascaris lumbricoides caused significant intestinal inflammation in 30% of infected individuals, while Giardia lamblia was associated with malabsorption syndrome in 15% of cases. Entamoeba histolytica was linked to liver abscesses in 10% of the infected participants.

Conclusion

Parasitic infections are highly prevalent in underserved communities, with significant pathological impacts on affected individuals.

A comparative study of traditional and molecular diagnostic methods for detection of gastrointestinal parasites in Nepalese migrants to the UK

BACKGROUND

We evaluated the results of examining a single faecal sample for gastrointestinal parasites (GIP) using a combination of traditional methods with multiplex qPCR for helminths and protozoa, compared to a reference standard of examining three faecal samples from each person using traditional diagnostic methods alone.

METHODS

Three faecal samples were collected at weekly intervals from 596 healthy Nepalese men. Each sample underwent formalin-ethyl acetate (FEA) concentration and light microscopy, and charcoal culture. The combined results of these investigations for all three stool samples were designated the reference standard. The first sample was also analysed using a multiplex TaqMan™ qPCR assay, screening for five helminths and three protozoa. We compared sensitivity and specificity of analysing the first faecal sample with qPCR alone, or a hybrid approach combining qPCR with traditional methods, to the reference standard. Additionally, a serum sample was taken from each participant for Strongyloides stercoralis IgG ELISA.

RESULTS

The reference standard identified 139 GIP infections in 133 (22.3%) participants. Use of qPCR alone in one stool identified 176 infections in 147 (24.8%) participants, rising to 187 infections in 156 (26.3%) when combined with FEA microscopy and charcoal culture. The sensitivity of this latter hybrid approach was 100% for Strongyloides spp., 90.9% for Trichuris trichiura, 86.8% for hookworm species and 75% for Giardia duodenalis compared to the reference standard. The hybrid approach increased the detected prevalence of G. duodenalis by 4.5% (27 cases) overall, T. trichiura by 2.9% (17 cases), Strongyloides spp. by 1% (6 cases), and hookworm by 0.5% (3 cases), compared to the reference standard.

CONCLUSION

Examination of a single faecal sample using qPCR alone showed superior or equivalent sensitivity to traditional methods for most GIP infections when both were compared to the reference standard. Combining molecular and traditional methods to analyse a single stool improved the detection rate for most studied parasites. This approach has value in settings where repeated sampling and/or faecal culture for helminths is impractical, but molecular diagnostics are available.

Helminthiasis in school-age children from Gresik, East Java, Indonesia

This study aims to investigate the soil-transmitted helminth infection among school-age children in Gresik, East Java, Indonesia. An analytical observational study with a cross-sectional design was conducted from July to November 2023 in selected elementary schools in Gresik, East Java, Indonesia. Logistic regression analysis was employed to assess the impact of each risk factor on the likelihood of infection transmission. A total of 183 school-age children were screened for the occurrence of helminth eggs in their feces. Twenty-two feces samples from 183 children were positive for helminth egg, consisting of 14 children infected by Ascaris lumbricoides (6.36 %), 3 children infected by Trichuris trichiura (1.304 %), 3 children infected by Oxyuris vermicularis (1.304 %), and 3 children infected by Hookworm (1.304 %). The highest prevalence was found in 7-year-old children (31.8 %). Children who pulled off shoes while in school were more likely to be infected with an overall OR of 8.392 (95 % CI 1.63 - 43.65). Children who played in the dumpsite were more likely to be infected with an overall OR of 4.521 (95 % CI 0.578 - 31.28). Children who washed before eating were more likely to be infected with an overall OR of 3.579 (95 % CI 0.587 - 21.835). Therefore, to lessen the prevalence of STHs among school-age children in Gresik, we recommend improving hygiene conditions in schools. The government should prioritize enrolling all primary schools in hygiene classes as the school health program.

Exposure of gut bacterial isolates to the anthelminthic drugs, ivermectin and moxidectin, leads to antibiotic-like phenotypes of growth inhibition and adaptation

Due to their broad-spectrum activities, ivermectin and moxidectin are widely used anthelminthics in veterinary and human medicine. However, ivermectin has recently been shown to perturbate bacterial growth. Given the macrolide-like structure of both ivermectin and moxidectin, there is a need to characterize the antibiotic spectrum of these anthelminthics and their potential implications in the development of cross-resistance to macrolides and other families of antibiotics. Here, we characterize growth dynamics of 59 bacterial isolates in presence of ivermectin and moxidectin. Further, we assessed the effect of repeated anthelminthic exposure in 5 bacterial isolates on sensitivity to different antibiotics, both via growth dynamics and minimal inhibitory concentration. We found, that anthelminthic growth phenotypes are comparable to a selection of tested antibiotics. Bacterial anthelminthic challenging resulted in decreased anthelminthic sensitivity, and to some extent, decreased antibiotic sensitivity. Hence, potential off-target effects of large-scale administration of ivermectin and moxidectin should be carefully monitored.

A type 2 immune circuit and arachidonic acid metabolism role in anti-nematode infection: evidence from transcriptome and targeted metabolome data in goat

The gastrointestinal nematode infection poses a covert threat to both humans and domestic animals worldwide, eliciting a type 2 immune response within the small intestine. Intestinal tuft cells detect the nematode and activated group 2 innate lymphoid cells. Tuft cell-derived leukotrienes (one of the metabolites of arachidonic acid) were found to drive rapid anti-helminth immunity, but it is still poorly understood whether the tuft cell-mediated type 2 immune circuit and arachidonic acid metabolism modulate anti-parasitic immunity in the gastric epithelium. This study was designed to evaluate the immunological responses of goats inoculated with or without H. contortus. Results showed that H. contortus infection induced a systemic type 2 immune response, characterised by lymphocyte proliferation and greater eosinophils both in peripheral blood and abomasal mucosa, as well as increased type 2 cytokines IL-4, IL-5, and IL-13. Infection of H. contortus altered the transcriptome of the abomasum epithelium, especially tuft cell-mediated circuit-key genes. The infection also influenced the abomasal microbiota, arachidonic acid metabolism and related lipid metabolites, accompanying with great increases in the secretion of leukotrienes and prostaglandins. These findings demonstrate the role of tuft cells mediated circuit in sensing H. contortus infection and immune activation, reveal the candidate function of arachidonic acid involved in anti-helminth immunity, and suggest novel strategies for the control of parasitic diseases in livestock and humans.

The concentration McMaster method for diagnosis of patent Ascaris and Trichuris infections in humans

In tropical and subtropical regions, soil-transmitted helminth (STH) infections such as Ascaris lumbricoides, Trichuris trichiura, and hookworms have a significant impact on public health. Globally, A. lumbricoides infects approximately 0.8 billion people, while T. trichiura infects around 500 million. This study involved a comparison of three diagnostic methods, Kato-Katz and two flotation methods (concentration McMaster, and simple McMaster), for the detection of Ascaris and Trichuris in human faeces. We conducted a comparison of the number of eggs in faeces (or faecal egg counts (FECs)) obtained with these methods using freshly collected samples that were positive for T. trichiura and spiked with a known quantity of Ascaris sp. eggs. Additionally, for the concentration McMaster method we assessed FECs after storing the samples at 5 °C for up to 21 days. The concentration McMaster method demonstrated superiority over the simple McMaster method in terms of higher detection levels for both helminths, while the Kato-Katz method yielded FEC values very close to the 'true' spiking values. Importantly, the concentration McMaster method was considerably easier to read compared with the Kato-Katz method, and it allowed for sample storage at 5 °C for up to 14 days without affecting FEC results. Consequently, we conclude that the concentration McMaster method is an effective and user-friendly alternative for diagnosis of Ascaris and Trichuris infections in humans. Furthermore, it offers the advantage of sample storage before analysis, enhancing flexibility in the workflow.

High-throughput screening of more than 30,000 compounds for anthelmintics against gastrointestinal nematode parasites

Gastrointestinal nematodes (GINs) are amongst the most common parasites of humans, livestock, and companion animals. GIN parasites infect 1-2 billion people worldwide, significantly impacting hundreds of millions of children, pregnant women, and adult workers, thereby perpetuating poverty. Two benzimidazoles with suboptimal efficacy are currently used to treat GINs in humans as part of mass drug administrations, with many instances of lower-than-expected or poor efficacy and possible resistance. Thus, new anthelmintics are urgently needed. However, screening methods for new anthelmintics using human GINs typically have low throughput. Here, using our novel screening pipeline that starts with human hookworms, we screened 30,238 unique small molecules from a wide range of compound libraries, including ones with generic diversity, repurposed drugs, natural derivatives, known mechanisms of action, as well as multiple target-focused libraries (e.g., targeting kinases, GPCRs, and neuronal proteins). We identified 55 compounds with broad-spectrum activity against adult stages of two evolutionary divergent GINs, hookworms ( Ancylostoma ceylanicum ) and whipworms ( Trichuris muris ). Based on known databases, the targets of these 55 compounds were predicted in nematode parasites. One novel scaffold from the diversity set library, F0317-0202, showed good activity (high motility inhibition) against both GINs. To better understand this novel scaffold's structure-activity relationships (SAR), we screened 28 analogs and created SAR models highlighting chemical and functional groups required for broad-spectrum activity. These studies validate our new and efficient screening pipeline at the level of tens of thousands of compounds and provide an important set of new GIN-active compounds for developing novel and broadly-active anthelmintics.

Contribution of socio-demographic factors in prevalence of soil-transmitted helminth infections among newly arrived laborers in Jeddah, Saudi Arabia

Background

Soil-transmitted diseases are caused by intestinal worms transmitted via various routes into the human body resulting in various clinical manifestations. This study aimed to investigate the socio-demographic factors contributing mainly to the prevalence of soil-transmitted helminths (STHs) among newly arrived laborers in Jeddah, Saudi Arabia.

Methods

A total of 188 stool specimens were collected and examined macroscopically and microscopically using different techniques. In addition, real-time PCR was used as a molecular tool to detect several STHs. The descriptive analysis was used to evaluate demographic data and categorical variables in association with STHs infection.

Results

Of all participants, the mean age was 26.08 ± 2.67 years, including 103 females and 85 males. A total of 86 (45.70%) were illiterate, followed by 60 (31.90%) of participants belonging to elementary level. STHs and other intestinal parasites were detected among 35 newly arrived laborers (18.61%). Nineteen cases (10.11%) were infected with STHs, including 15 cases with one STHs (four A. lumbricoides, four N. americanus, four T. trichiura, two S. stercoralis, one A. duodenale) and four cases with two STHs (two T. trichiura and N. americanus; one S. stercoralis and A. duodenale; one T. trichiura and S. stercoralis). High rates of STHs infection were detected among drivers (11.70%) followed by housemaids (11.20%), but with no significant association to occupation. Higher rates of STHs infection were detected among those used to walk on soil barefoot in their home countries before arriving in Jeddah.

Conclusion

This study found that none of the newly arrived expatriate laborers in Jeddah was aware of STHs. About 10% of them had infection with one or two STHs, mainly among newly arrived laborers from Asian countries. There is a need for awareness programs and regular screening for STHs and other intestinal parasites among newly arrived expatriate laborers.

Low prevalence of soil transmitted helminth infection in Ugandan children hospitalized with severe malaria

Co-infection by intestinal helminths and Plasmodium spp. may be common in endemic communities. Several studies have identified a relationship between helminth infection, Plasmodium spp. infection and malaria severity. However, the relationship is not well defined, and results are inconclusive. We analyzed 202 stool samples from a cohort of children with severe malaria enrolled in two hospitals in Uganda from 2014-2017 and asymptomatic community children from the same household or neighborhood and enrolled at the same time, all 6 months to 48 months of age. We investigated if intestinal helminth infection modified risk of severe malaria. We extracted nucleic acids from stool and tested them for six helminth species (Anyclostoma duodenale, Ascaris lumbricoides, Necator americanus, Strongyloides stercolaris, Trichuris trichiura, Shistosoma mansoni) using highly sensitive quantitative PCR. We found a low prevalence of infection by ≥1 intestinal helminth species in children with severe malaria (5.1%, n=9/177) and community control children (4.0%, n=1/25). Infection by ≥1 of the helminths assessed was not associated with severe malaria (aRR = 1.0, 95% Confidence Interval = 0.82, 1.3, p = 0.78). In 2003 Uganda instituted a national deworming program, with anti-helminth medication provided twice annually to children 6 months to 5 years of age. In these areas of Uganda, the national deworming campaign has been highly successful, as stool-based helminth infection was rare even when using highly sensitive methods of detection and was not a major contributor to risk of severe malaria.

Intestinal Parasitic Infections May Be Overlooked Drivers of the Tuberculosis Pandemic

The burden of tuberculosis (TB) is disproportionate in tropical and subtropical regions, where parasitic coinfections are common. Given the significant geographical overlap between TB and intestinal parasitic infections, it is important to consider the implications of intestinal parasitic infections for the TB pandemic. Intestinal parasitic infections have been theorized to increase vulnerability to TB by altering the inflammatory milieu, inducing undernutrition that blunts the immune response, and affecting drug pharmacokinetics. In this perspective, we provide a background of the epidemiological and immunological evidence that links parasitic infections to increased risk of TB progression and worse treatment outcomes. We also identify gaps in our knowledge and call for increased research on TB-parasitic coinfections to ensure action on a potentially widespread TB comorbidity.

Towards integrated cross-sectoral surveillance of pathogens and antimicrobial resistance: Needs, approaches, and considerations for linking surveillance to action

Pathogenic and antimicrobial-resistant (AMR) microorganisms are continually transmitted between human, animal, and environmental reservoirs, contributing to the high burden of infectious disease and driving the growing global AMR crisis. The sheer diversity of pathogens, AMR mechanisms, and transmission pathways connecting these reservoirs create the need for comprehensive cross-sectoral surveillance to effectively monitor risks. Current approaches are often siloed by discipline and sector, focusing independently on parts of the whole. Here we advocate that integrated surveillance approaches, developed through transdisciplinary cross-sector collaboration, are key to addressing the dual crises of infectious diseases and AMR. We first review the areas of need, challenges, and benefits of cross-sectoral surveillance, then summarise and evaluate the major detection methods already available to achieve this (culture, quantitative PCR, and metagenomic sequencing). Finally, we outline how cross-sectoral surveillance initiatives can be fostered at multiple scales of action, and present key considerations for implementation and the development of effective systems to manage and integrate this information for the benefit of multiple sectors. While methods and technologies are increasingly available and affordable for comprehensive pathogen and AMR surveillance across different reservoirs, it is imperative that systems are strengthened to effectively manage and integrate this information.

Baseline gut microbiota diversity and composition and albendazole efficacy in hookworm-infected individuals

Soil-transmitted helminth (STH) infections account for a significant global health burden, necessitating mass drug administration with benzimidazole-class anthelmintics, such as albendazole (ALB), for morbidity control. However, ALB efficacy shows substantial variability, presenting challenges for achieving consistent treatment outcomes. We have explored the potential impact of the baseline gut microbiota on ALB efficacy in hookworm-infected individuals through microbiota profiling and machine learning (ML) techniques. Our investigation included 89 stool samples collected from hookworm-infected individuals that were analyzed by microscopy and quantitative PCR (qPCR). Of these, 44 were negative by microscopy for STH infection using the Kato-Katz method and qPCR 21 days after treatment, which entails a cure rate of 49.4%. Microbiota characterization was based on amplicon sequencing of the V3-V4 16S ribosomal RNA gene region. Alpha and beta diversity analyses revealed no significant differences between participants who were cured and those who were not cured, suggesting that baseline microbiota diversity does not influence ALB treatment outcomes. Furthermore, differential abundance analysis at the phylum, family and genus levels yielded no statistically significant associations between bacterial communities and ALB efficacy. Utilizing supervised ML models failed to predict treatment response accurately. Our investigation did not provide conclusive insights into the relationship between gut microbiota and ALB efficacy. However, the results highlight the need for future research to incorporate longitudinal studies that monitor changes in the gut microbiota related to the infection and the cure with ALB, as well as functional metagenomics to better understand the interaction of the microbiome with the drug, and its role, if there is any, in modulating anthelmintic treatment outcomes in STH infections. Interdisciplinary approaches integrating microbiology, pharmacology, genetics and data science will be pivotal in advancing our understanding of STH infections and optimizing treatment strategies globally.

A Mixed-Methods Evaluation of Mainstreaming Mass Drug Administration for Schistosomiasis and Soil-Transmitted Helminthiasis in Four Districts of Nigeria

In Nigeria, mass drug administration (MDA) for schistosomiasis (SCH) and soil-transmitted helminthiasis (STH) has often been coordinated with other programs that receive greater external funding. As these programs reach stop MDA milestones, SCH and STH programs will likely need to transition implementation, or "mainstream," to domestic support. A mixed-methods study was conducted in four districts before (2021) and after (2022) mainstreaming to evaluate its impact on MDA coverage. Household surveys were done in 30 villages per district pre- and post-mainstreaming. All selected communities were eligible for STH treatment; around a third were eligible for SCH treatment. Mass drug administration was primarily conducted in schools. A total of 5,441 school-aged children were included in pre-mainstreaming and 5,789 were included in post-mainstreaming. Mass drug administration coverage was heterogeneous, but overall, mebendazole coverage declined nonsignificantly from 81% pre-mainstreaming to 76% post-mainstreaming (P = 0.09); praziquantel coverage declined significantly from 73% to 55% (P = 0.008). Coverage was significantly lower among unenrolled children or those reporting poor school attendance in nearly every survey. For the qualitative component, 173 interviews and 74 focus groups were conducted with diverse stakeholders. Respondents were deeply pessimistic about the future of MDA after mainstreaming and strongly supported a gradual transition to full government ownership. Participants formulated recommendations for effective mainstreaming: clear budget allocation by governments, robust and targeted training, trust building, and comprehensive advocacy. Although participants lacked confidence that SCH and STH programs could be sustained after reductions in external support, initial results indicate that MDA coverage can remain high 1 year into mainstreaming.

Probiotics: an alternative anti-parasite therapy

This paper review about probiotic effects and mechanism of action against the gut and non-gut helminths and protozoan parasites. Gastrointestinal parasitic infections are considered a serious health problem and are widely distributed globally. The disease process which emanates from this parasite infection provides some of the many public and veterinary health problems in the tropical and sub-tropical countries. Prevention and control of the parasite disease is through antihelmintic and anti-protozoan drugs, but, due to the increasing emergence of such drug resistance, eradication of parasite infestation in human and livestock still lingers a challenge, which requires the development of new alternative strategies. The use of beneficial microorganisms i.e. probiotics is becoming interesting due to their prophylactic application against several diseases including parasite infections. Recent studies on the interactions between probiotics, parasites and host immune cells using animal models and in vitro culture systems has increased considerably and draw much attention, yet the mechanisms of actions mediating the positive effects of these beneficial microorganisms on the hosts remain unexplored. Therefore, the aim of the present review is to summarize the latest findings on the probiotic research against the gut and non-gut parasites of significance.

Persistent transmission of soil-transmitted helminths despite 16 years of uninterrupted Mebendazole- and ivermectin-based preventive chemotherapy in the Lomie Health District (East Region, Cameroon): The emergency of complementary control strategies

BACKGROUND

The control of the Soil-Transmitted Helminths (STH) infections primarily relies on the school-based Preventive Chemotherapy (PCT) with mebendazole. Given the efficacy of ivermectin on STH, the control of the latter is expected to be potentialized in areas where ivermectin is also distributed for onchocerciasis and/or lymphatic filariasis control/elimination. This study aimed to assess the prevalence and intensity of STH in the Lomie Health District where annual school-based deworming campaigns and community-directed treatments with Ivermectin have been underway for almost two decades.

METHODOLOGY/PRINCIPAL FINDINGS

A quantitative cross-sectional study was conducted in 10 schools of the Lomie Health District, East Region, Cameroon. Stool samples were collected from school-aged children and analysed using the Kato-Katz technique. Semi-structured questionnaires were administered to enrolees to assess compliance with water, sanitation, and hygiene (WASH). Of the 491 children (median age: 9 years; IQR: 7-10) enrolled, 83.9% (95% CI: 80.3-87.1) were infected with at least one STH species. Trichuris trichiura was the predominant species (78.5%), and no hookworm was found. The prevalence trend slightly decreased between 1987 and 2010 (~8%) and remained unchanged since 2010 (p-value = 0.05). Overall, 46.8% and 41.8% of children were heavy-to-moderately infected with Ascaris lumbricoides and T. trichiura. Poor hand hygiene (OR: 2.24, 95% IC: 1.4-3.4, p-value = 0.0002) and the use of river as a source of drinking water (OR: 14.8, 95% IC: 6.9-33.3, p-value = 0.0001) were the main risk factors associated with the STH infection in Lomie Health District.

CONCLUSIONS/SIGNIFICANCE

The persistent high prevalence and intensity of STH infection despite 16 years of mebendazole-based PCT and expected collateral impact of ivermectin mass distribution, points to plausible implementation gaps, poor compliance to WASH or sub-optimal efficacy of the anthelminthics used. This study highlights the need to further assess the cause of the persistent high prevalence and implement context-adapted control measures in order to curb STH transmission.

Human Ascaris infection is associated with higher frequencies of IL-10 producing B cells

INTRODUCTION

Ascaris lumbricoides has dual effects on the immune system of infected hosts. The IgE response to this parasite has been thoroughly studied, but little is known about cellular responses induced by infection. This study aims to explore the interplay between A. lumbricoides infection and B cell responses, especially B regulatory cells.

METHODS

Participants from Santa Catalina, Bolívar, Colombia, a helminth-endemic town, were screened for soil-transmitted helminthiasis (STH) using stool examinations. Eighteen A. lumbricoides-infected and 11 non-infected subjects were selected. Blood samples were analyzed for Breg cells and related cytokines, and immunoglobulins specific to the A. lumbricoides excretory/secretory product, ABA-1.

RESULTS

Infected subjects exhibited higher frequencies of Breg cells, especially those with a higher A. lumbricoides egg burden. Higher frequencies of different Breg subsets were observed in infected individuals, with CD25+CD71+CD73- B cells being notably increased in strongly infected individuals. Additionally, A. lumbricoides infection was associated with reduced levels of circulating ABA-1-specific IgG1 and IgE. IL-10+ B cell frequencies correlated inversely with ABA-1-specific IgE.

CONCLUSIONS

A. lumbricoides infection has a significant impact on the immune response, particularly on Breg cell populations and antibody responses. Our findings suggest that A. lumbricoides infection mediates a dose-dependent immunosuppressive response characterized by an increase in Breg cells and concomitant suppression of ABA-1-specific humoral responses.

Soil surveillance for monitoring soil-transmitted helminths: Method development and field testing in three countries

BACKGROUND

One-fifth of the global population is infected with soil-transmitted helminths (STH). Mass drug administration (MDA) with deworming medication is widely implemented to control morbidity associated with STH infections. However, surveillance of human infection prevalence by collecting individual stool samples is time-consuming, costly, often stigmatized, and logistically challenging. Current methods of STH detection are poorly sensitive, particularly in low-intensity and low-prevalence populations.

METHODOLOGY/PRINCIPAL FINDINGS

We aimed to develop a sensitive and specific molecular method for detecting STH DNA in large volumes of soil (20 g) by conducting laboratory and proof of concept studies across field sites in Kenya, Benin, and India. We collected human stool (n = 669) and soil (n = 478) from 322 households across the three study sites. We developed protocols for DNA extraction from 20 g of soil and qPCR to detect Ascaris lumbricoides, Trichuris trichiura, Necator americanus, and Ancylostoma duodenale. Agreement between detection of STH via qPCR, digital droplet PCR (ddPCR), and microscopy-based methods was assessed using the Cohen's Kappa statistic. Finally, we estimated associations between soil characteristics and detection of STH in soil by qPCR, as well as between STH detected in soil and STH detected in stool from matched households, adjusting for soil characteristics. The overall prevalence of STH in soil by qPCR was 31% for A. lumbricoides, 3% for T. trichiura, and 13% for any hookworm species. ddPCR and qPCR performed similarly. However, there was poor agreement between STH detected in soil by qPCR versus light microscopy. Microscopy underestimated the prevalence of A. lumbricoides and N. americanus and overestimated T. trichiura. Detection of an STH species in household soil was strongly associated with increased odds of a household member being infected with that same species.

CONCLUSIONS/SIGNIFICANCE

Soil surveillance for STH has several benefits over stool-based surveillance, including lower cost and higher success rates for sample collection. Considering that delivery of MDA occurs at the community level, environmental surveillance using molecular methods could be a cost-effective alternate strategy for monitoring STH in these populations.

Intestinal helminth infection impairs vaccine-induced T cell responses and protection against SARS-CoV-2 in mice

Although vaccines have reduced the burden of COVID-19, their efficacy in helminth infection-endemic areas is not well characterized. We evaluated the impact of infection by Heligmosomoides polygyrus bakeri (Hpb), a murine intestinal roundworm, on the efficacy of an mRNA vaccine targeting the Wuhan-1 spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in mice. Although immunization generated similar B cell responses in Hpb-infected and uninfected mice, polyfunctional CD4+ and CD8+ T cell responses were markedly reduced in Hpb-infected mice. Hpb-infected and mRNA-vaccinated mice were protected against the ancestral SARS-CoV-2 strain WA1/2020, but control of lung infection was diminished against an Omicron variant compared with animals immunized without Hpb infection. Helminth-mediated suppression of spike protein-specific CD8+ T cell responses occurred independently of signal transducer and activator of transcription 6 (STAT6) signaling, whereas blockade of interleukin-10 (IL-10) rescued vaccine-induced CD8+ T cell responses. Together, these data show that, in mice, intestinal helminth infection impaired vaccine-induced T cell responses through an IL-10 pathway, which compromised protection against antigenically drifted SARS-CoV-2 variants.

Prevalence of Plasmodium and Soil-Transmitted Helminth Coinfection and Associated Factors among Malaria-Suspected Patients Attending Shewa Robit Health Center, North-Central Ethiopia

Plasmodium and soil-transmitted helminth (STH) coinfection is a major public health problem in developing countries. Its prevalence and associated factors are poorly addressed in the available research. Therefore, this study aimed to assess Plasmodium-STH coinfection prevalence and associated factors among malaria-suspected patients attending Shewa Robit Health Center, north-central Ethiopia. A cross-sectional study was conducted among 379 malaria-suspected patients attending Shewa Robit Health Center from April to May 2023. Stool and blood samples were collected from each participant. Plasmodium and STHs were detected from blood and stool samples by using blood film and the Kato-Katz method, respectively. Data were entered into Epi Info version 7 and analyzed by SPSS version 26. Descriptive statistics were used to compute Plasmodium-STH coinfection. Logistic regression was used to identify associated factors. Variables with a P-value <0.05 were considered statistically significant. Among the study participants, 27.9%, 20.3%, and 13.4% were positive for Plasmodium, STHs, and Plasmodium-STH coinfection, respectively. The prevalence of Plasmodium-Ascaris lumbricoides coinfection was high (7.6%). Unavailability of insecticide-treated bed nets (ITNs), improper use of ITNs, absence of indoor residual spraying, presence of stagnant water, and previous malaria infection were significantly associated (P <0.01) with Plasmodium infection. Being illiterate, using an unimproved latrine, having an untrimmed fingernail, and practicing open defecation were also significantly associated (P <0.03), with STH infection. Being male, illiterate, and living in rural areas were significantly associated (P <0.03) with Plasmodium-STH coinfection. The prevalence of Plasmodium-STH coinfection was high in malaria-endemic areas. Therefore, malaria-suspected cases should be checked for STH infection.

Mohammed A, Althaus F, Abdulla S, Tanner M, Daubenberger C, Genton B. The impact of soil transmitted helminth on malaria clinical presentation and treatment outcome: A case control study among children in Bagamoyo district, coastal region of Tanzania

BACKGROUND

Parasitic infectious agents rarely occur in isolation. Epidemiological evidence is mostly lacking, and little is known on how the two common parasites Plasmodium and soil transmitted helminths (STH) interact. There are contradictory findings in different studies. Synergism, antagonism and neutral effect have been documented between Plasmodium and STH. This study investigated the impact of STH on clinical malaria presentation and treatment outcome.

METHODS

A matched case control study with a semi longitudinal follow up according to World Health Organization (WHO) antimalarial surveillance guideline was done among children aged 2 months to 9 years inclusively living in western rural areas of Bagamoyo, coastal region of Tanzania. Cases were children with uncomplicated and severe malaria enrolled from the health facilities while controls were children with asymptomatic Plasmodium parasitemia enrolled from the same community.

RESULTS

In simple conditional regression analysis there was a tendency for a protective effect of STH on the development of clinical malaria [OR = 0.6, 95% CI of 0.3-1.3] which was more marked for Enterobius vermicularis species [OR = 0.2, 95% CI of 0.0-0.9]. On the contrary, hookworm species tended to be associated with increased risk of clinical malaria [OR = 3.0, 95% CI of 0.9-9.5]. In multiple conditional regression analysis, the overall protective effect was lower for all helminth infection [OR = 0.8, 95% CI of 0.3-1.9] but remained significantly protective for E. vermicularis species [OR = 0.1, 95% CI of 0.0-1.0] and borderline significant for hookworm species [OR = 3.6, 95% CI of 0.9-14.3]. Using ordinal logistic regression which better reflects the progression of asymptomatic Plasmodium parasitemia to severe malaria, there was a 50% significant protective effect with overall helminths [OR = 0.5, 95% CI of 0.3-0.9]. On the contrary, hookworm species was highly predictive of uncomplicated and severe malaria [OR = 7.8, 95% (CI of 1.8-33.9) and 49.7 (95% CI of 1.9-1298.9) respectively]. Generally, children infected with STH had higher geometric mean time to first clearance of parasitemia.

CONCLUSION

The findings of a protective effect of E. vermicularis and an enhancing effect of hookworms may explain the contradictory results found in the literature about impact of helminths on clinical malaria. More insight should be gained on possible mechanisms for these opposite effects. These results should not deter at this stage deworming programs but rather foster implementation of integrated control program for these two common parasites.

Detection of soil-transmitted helminths and Schistosoma spp. by nucleic acid amplification test: Results of the first 5 years of the only international external quality assessment scheme

BACKGROUND

Infections with soil-transmitted helminths (STH) and schistosomiasis (SCH) result in a significant global health burden, particularly in rural communities in low and middle-income countries. While microscopy remains the primary diagnostic method for STH and SCH in resource-limited settings, nucleic acid amplification tests (NAATs) are gaining prominence as tools for evaluation of public health control programs in endemic countries, and individual diagnosis in high-income countries. Despite the high sensitivity and specificity of NAATs, previous research has highlighted inter-laboratory variations, both in technical and clinical performance, justifying the need for continuous proficiency testing.

METHODOLOGY

Results from 5 rounds over a 5-year period of the so far only longitudinal international Helminth External Molecular Quality Assessment Scheme (HEMQAS), coordinated by the Dutch Foundation for Quality Assessment in Medical Laboratories (SKML), were examined in order to (i) assess the diagnostic proficiency of laboratories in detecting helminths in stool and (ii) identify potential factors contributing to variations in performance.

OUTCOME AND CONCLUSIONS

Thirty-six laboratories, from 18 countries and 5 continents, participated in HEMQAS. The overall diagnostic performances were satisfying, with remarkably low numbers (<2%) of false-positive results. False-negative results were more often reported for stool (15%) than for DNA (5%) samples. False-negative results varied largely between targets (the highest number (29%) for Trichuris trichiura). Twenty-five laboratories provided a sufficient number of results for a robust comparison between participating laboratories, which confirmed substantial inter-laboratory variability in quantitative NAAT results (Cq-values). This variability likely arises from differences in pre-treatment, DNA isolation and DNA-target amplification procedures. This study emphasizes the complexity of molecular diagnosis for STH and SCH, highlighting the critical role of proper stool preparation and DNA isolation methods. The results underscore the necessity for laboratory professionals and public health decision-makers to recognize these complexities and continuously undertake external quality assessment schemes to ensure accurate and reliable performance in molecular diagnosis.

Interaction between Intestinal Parasites and the Gut Microbiota: Implications for the Intestinal Immune Response and Host Defence

Intestinal parasites, including helminths and protozoa, account for a significant portion of the global health burden. The gastrointestinal (GI) tract not only serves as the stage for these parasitic infections but also as the residence for millions of microbes. As the intricacies of the GI microbial milieu continue to unfold, it is becoming increasingly apparent that the interactions between host, parasite, and resident microbes help dictate parasite survival and, ultimately, disease outcomes. Across both clinical and experimental models, intestinal parasites have been shown to impact microbial composition and diversity. Reciprocally, microbes can directly influence parasitic survival, colonization and expulsion. The gut microbiota can also indirectly impact parasites through the influence and manipulation of the host. Studying this host-parasite-microbiota axis may help bring about novel therapeutic strategies for intestinal parasitic infection as well as conditions such as inflammatory bowel disease (IBD). In this review, we explore the relationship between intestinal parasites, with a particular focus on common protozoa and helminths, and the gut microbiota, and how these interactions can influence the host defence and intestinal immune response. We will also explore the impact of this tripartite relationship in a clinical setting and its broader implications for human health.

Unusual Presentation of Pleural Space Ascariasis Infection from Eastern Sudan: A Case Report

Background

Ascaris lumbricoides is a common infectious parasite of the gastrointestinal tract worldwide, but the invasion of the pleural cavity is rare.

Case Report

A 45-year-old man from Eastern Sudan presented to the emergency department complaining of breathlessness, cough stained with blood, and chest pain one month before his presentation. Also, he complained of high-grade fever for two weeks associated with sweating. Diagnosis of hydropneumothorax was made and a chest tube was inserted, two days later we found three adult A. lumbricoides worms in the chest drain.

Conclusion

The patient was treated with Albendazole 200 mg, orally twice, daily for seven days, he improved and was referred to a cardiothoracic surgeon for more assessment. Our study highlights that internal medicine specialists should know about pleural ascariasis when patients present with respiratory signs and symptoms, especially in A. lumbricoides endemic regions like Eastern Sudan.

The enhancive effect of the 2014-2016 El Niño-induced drought on the control of soil-transmitted helminthiases without anthelmintics: A longitudinal study

BACKGROUND

Soil-transmitted helminthiases (STHs) are common in tropical and subtropical regions. Southern Thailand experiences an extended rainy season, leading to persistently moist soil. This condition supports the life cycle of STHs, hindering effective control due to reinfection and low drug efficacy. We implemented a novel STH control strategy during the dry season aimed at decreasing reinfection rates without enhancing sanitation or hygiene practices. However, there were unexpected, prolonged droughts linked to El Niño events from 2014 to 2016. Additionally, we assessed the effects of these drought conditions on further control measures without the use of anthelmintics.

METHODOLOGY/PRINCIPAL FINDINGS

A longitudinal study was conducted from 2012 to 2016. Stool samples collected from 299 participants were analyzed using the Kato-Katz and agar plate culture methods. Participants who tested positive for STHs received a single 400 mg dose of albendazole. The efficacy of the treatment was evaluated three weeks later. To confirm the control measures were implemented during the dry season, we monitored the number of rainy days following albendazole treatment for 52 days, of which 38 were without rain. Follow-up stool examinations were carried out in 2013 and 2016, with no additional doses of albendazole administered. Rainfall and rainy day data, which served as indicators of unexpected droughts due to El Niño, were collected from the nearest local meteorological stations. Before the drought, there was a decrease in STH prevalence in 2013-except for trichuriasis-attributable to the dry season control efforts. Despite these efforts, STH prevalence remained high. Remarkably, in 2016, following the drought period, the prevalence of trichuriasis, which had not changed previously, spontaneously declined without further albendazole treatment compared to 2013. Furthermore, the prevalence of strongyloidiasis remained unchanged likely due to its low susceptibility to drought conditions, as it can reproduce within hosts. Conversely, the prevalence of other STHs consistently declined. The drought and possible improvements in sanitation and hygiene practices contributed to this decrease by reducing rates of reinfection and new infection and by increasing the natural cure rate. Additionally, some participants infected with hookworms or Trichuris who were not cured by albendazole experienced natural remission.

CONCLUSIONS/SIGNIFICANCE

Control measures implemented during the dry season, combined with a 14-month-long drought induced by the El Niño event of 2014-2016, and some improvements in sanitation and hygiene practices, contributed to a decrease in both the prevalence and intensity of STHs, except for S. stercoralis. Over time, S. stercoralis is likely to become the predominant species among the STHs.

Prevalence of intestinal parasitic infections among the pregnant women in South and South East Asian countries: A systematic review and meta-analysis

Intestinal parasitic infections (IPIs) are a major health concern in resource-limited countries of South/South-East Asian region. Despite posing a potential threat to maternal and fetal health, there is limited data available on the actual burden of IPI among pregnant women. Through this systemic review and meta-analysis, we sought to determine the pooled prevalence of IPI and species-specific prevalence among pregnant women in this region. Subgroup analysis was done by region, stool examination technique, and study settings. Among 220 retrieved studies, 21 studies from 8 countries across the region were found eligible and included in this study. The estimated overall pooled prevalence of IPIs among pregnant women was 43.15% (95% confidence interval: 30.66-56.10). The most prevalent IPI was Ascaris lumbricoides (25.14%) and predominant protozoa was Entamoeba histolytica/dispar (6.96%). In subgroup analysis, the estimated pooled prevalence of IPIs in Nepal, India, Thailand, and Thai-Burmese Border was 40.88%, 28.33%, 55.38%, and 23.78%, respectively. Studies using Kato-Katz technique for stool examination showed the highest estimated pooled IPI prevalence (62.70%). The prevalence of IPI was found to be lower in facility-based studies (38.12%) than that of studies done in the community (66.21%). Considering the high burden of IPI in pregnant women as estimated in our review and the already established impact of IPI infection on maternal health and fetal outcomes, we recommend implementation of the preventive chemotherapy during routine antenatal checkups.

Meta-analysis and public policy: Reconciling the evidence on deworming

The WHO recommends mass drug administration (MDA) for intestinal worm infections in areas with over 20% infection prevalence. Recent Cochrane meta-analyses endorse treatment of infected individuals but recommend against MDA. We conducted a theory-agnostic random-effects meta-analysis of the effect of multiple-dose MDA and a cost-effectiveness analysis. We estimate significant effects of MDA on child weight (0.15 kg, 95% CI: 0.07, 0.24; P < 0.001), mid-upper arm circumference (0.20 cm, 95% CI: 0.03, 0.37; P = 0.02), and height (0.09 cm, 95% CI: 0.01, 0.16; P = 0.02) when prevalence is over 20% but not on Hb (0.06 g/dL, 95% CI: -0.01, 0.14; P = 0.1). These results suggest that MDA is a cost-effective intervention, particularly in the settings where it is recommended by the WHO.

Burden and factors influencing intestinal parasitic infections among food handlers in Gondar City, Northwest Ethiopia

Background

Intestinal parasitic infections pose significant global health challenges, particularly in developing countries. Asymptomatic infections often present a considerable burden with food handlers serving as potential carriers. In Ethiopia, the prevalence of these parasites varies across regions, and accurate data in the study area is lacking. Therefore, this study aimed to investigate the prevalence of intestinal parasites among food handlers working in hotels and restaurants in Gondar City, Northwest Ethiopia.

Methods

A cross-sectional study collected stool samples from food handlers alongside a structured questionnaire gathering socio-demographic and hygiene practice information. Stool specimens were screened for intestinal parasites using direct wet mount and formol-ether concentration techniques. The collected data were checked for completeness, entered into EpiData software version 3.1, and exported to SPSS version 20 for analysis. A multivariable logistic regression analysis was deemed statistically significant if the p-value was less than 0.05.

Results

A total of 257 food handlers working in hotels and restaurants in Gondar City participated in the study. Of these, 33.5% (86/257) were found positive for one or more intestinal parasites, with a 95% confidence interval (CI) of 28.0-39.5%. The study identified nine types of intestinal parasites, with E. histolytica/dispar (8.2%, 21/257) and Ascaris lumbricoides (6.6%, 17/257) being the predominant parasites, followed by hookworm (3.5%, 9/257) and S. mansoni (2.3%, 6/257). The prevalence of mixed infections was 9.3% (24/257). A significant association was observed between intestinal parasitic infection and the educational level of food handlers.

Conclusion

In this study, a high prevalence of intestinal parasites was detected indicating poor hygiene practices of the food handlers at the study site. Even the prevalence of mixed infections was high. Regular training, strict adherence to personal hygiene and food-handling practices, and routine inspections and medical checkups for food handlers are crucial.

Helminthiasis and malaria co-infection among women of reproductive age in a rural setting of Kilifi County, coastal Kenya: A mixed method study

Soil transmitted helminthiasis (STH), Schistosoma haematobium and malaria co-infection lead to increased susceptibility to other infections and poor pregnancy outcomes among women of reproductive age (WRA). This study sought to establish risk factors, burden of co-infection with STH, S. haematobium and Plasmodium sp. among WRA in Kilifi County, Kenya.A mixed method cross-sectional study was conducted on 474 WRA in 2021. Simple random sampling was used to select WRA from four villages in two purposively sampled sub-counties. Study participants were interviewed, and stool samples collected and analysed using Kato-Katz technique for STH. Urine samples were collected for examination of S. haematobium while malaria microscopic test was done using finger prick blood samples. Further, 15 focus group discussions (FGDs) were conducted with purposively selected WRA and qualitative data analyzed thematically using Nvivo software. Quantitative and qualitative methods were triangulated to comprehensively strengthen the study findings. Prevalence of S. haematobium was 22.3% (95%CI: 13.5-36.9), any STH 5.2% (95%CI: 1.9-14.3) and malaria 8.3% (95%: 3.8-18.2). Co-infections between any STH and S. haematobium was 0.8% (95%CI: 0.2-3.2) and between S. haematobium and malaria 0.8% (95%CI: 0.2-3.1). Multivariable analysis showed increased odds of any STH infections among participants in Rabai Sub-County, (aOR = 9.74; p = 0.026), businesswomen (aOR = 5.25; p<0.001), housewives (aOR = 2.78; p = 0.003), and casual laborers (aOR = 27.03; p<0.001). Qualitative analysis showed that the three parasitic diseases were common and responsible for possible causes of low birth weight, susceptibility to other infections and complications such as infertility and cancer later in life.The study demonstrated that STH, S. haematobium and malaria are still a public health problem to WRA. Some of the associated risks of infection were geographical location, socio-economic and WASH factors. Hence the need to implement integrated control efforts of the three parasitic infection.

Understanding Drug Exposure and Trichuris trichiura Cure Rates: A Pharmacometric Approach for Albendazole-Ivermectin Co-medication in Tanzania and Côte d'Ivoire

BACKGROUND AND OBJECTIVE

Trichuriasis caused by the human whipworm Trichuris trichiura poses a significant public health concern. Albendazole-ivermectin co-medication is currently the most effective treatment. Studies conducted in Tanzania and Côte d'Ivoire unveiled differences in efficacy for albendazole-ivermectin combination therapy in both countries. A pharmacometrics approach was used to assess co-medication and study population effects on the pharmacokinetics of the two main metabolites of albendazole. An exploratory exposure-efficacy analysis was also carried out to investigate relationships between exposure measures and the egg reduction rate.

METHODS

Pharmacokinetic data from studies in Tanzania and Côte d'Ivoire in adolescents (aged 12-19 years) were included in the pharmacometric analysis. Participants received a single dose of either albendazole 400 mg alone or in combination with ivermectin 200 µg/kg. A pharmacometric analysis was performed to investigate the potential effects of the study population and co-administered ivermectin on the apparent clearance of the metabolites of albendazole. Non-linear mixed-effects modeling was conducted with MonolixSuite 2023R1. The pharmacokinetic exposure measures derived from simulations with individual model parameters were used in the exploratory-exposure response analysis.

RESULTS

Pharmacokinetic profiles were best described by a two-compartment model for albendazole sulfoxide and a one-compartment model for albendazole sulfone, with a transit compartment and linear elimination. While no co-medication effect was found, apparent clearance of albendazole sulfoxide (albendazole sulfone) in the Tanzanian study population was 75% (46%) higher than that in the Côte d'Ivoire study population. Exposure-efficacy response analyses indicated that peak concentration and the time-above-exposure threshold were associated with the egg reduction rate.

CONCLUSIONS

Study population but not co-administered ivermectin showed an effect on apparent clearance of albendazole sulfoxide and albendazole sulfone. Polymorphisms in drug-metabolizing enzymes and host-parasite interaction may explain this result. Difference in drug exposure did not explain the disparate efficacy responses in Tanzania and Côte d'Ivoire. Peak concentration and time-above-threshold were exposure measures associated with the egg reduction rate. Further studies evaluating genetic and resistance patterns in various regions in Africa are warranted.

Presentation of Ascariasis as a Cause of Acute Intestinal Obstruction

Ascariasis infection is prevalent in tropical and subtropical locations worldwide. The occurrence of ascariasis is associated with poverty, inadequate hygiene, and inadequate fecal sanitation. This helminth often resides innocuously in the small intestine, but it may sometimes lead to intestinal blockage or perforation, resulting in peritonitis, a condition frequently seen in children. Ascariasis may also migrate via the ampulla of Vater, leading to the development of cholangitis, pancreatitis, cholecystitis, and, in rare cases, hepatic abscesses. Occasionally, an Ascaris-induced hepatic abscess may manifest as an acute abdomen, resembling an acute pyogenic abscess. We report the case of a four-and-a-half-year-old male child from Khedi Sikarpur, Haridwar, India, who was admitted to the pediatric department. The patient presented with acute colicky abdominal pain localized to the abdomen, accompanied by vomiting and constipation for three days. Additionally, the patient experienced abdominal distension for one day. There was no history of bleeding manifestations or decreased urine output.

Hookworm genomics: dusk or dawn?

Hookworms are parasites, closely related to the model nematode Caenorhabditis elegans, that are a major economic and health burden worldwide. Primarily three hookworm species (Necator americanus, Ancylostoma duodenale, and Ancylostoma ceylanicum) infect humans. Another 100 hookworm species from 19 genera infect primates, ruminants, and carnivores. Genetic data exist for only seven of these species. Genome sequences are available from only four of these species in two genera, leaving 96 others (particularly those parasitizing wildlife) without any genomic data. The most recent hookworm genomes were published 5 years ago, leaving the field in a dusk. However, assembling genomes from single hookworms may bring a new dawn. Here we summarize advances, challenges, and opportunities for studying these neglected but important parasitic nematodes.

Pattern and predictor of hookworm re-infection among schoolchildren in three districts of Amhara Region, northwest Ethiopia

BACKGROUND

Despite integrated prevention and control measures, the prevalence of hookworm is still high in Ethiopia. The re-infection rates and predictors are poorly addressed. Therefore, this study aimed to determine the patterns of hookworm re-infection rates and predictors among schoolchildren in northwest Ethiopia.

METHODS

A prospective follow-up study was conducted among 86 schoolchildren from May to December 2022. Data on predictors was collected using a questionnaire. Stool samples were collected and processed via Kato-Katz, McMaster, and spontaneous tube sedimentation techniques. All hookworm-infected children were treated with albendazole and followed for six months. The re-infection rates of hookworm were checked in the 4th and 6th months. Data was entered into Epi-data version 3.1 and analysed using SPSS version 25. Descriptive statistics were used to compute the re-infection rate. The associations of predictors with hookworm re-infection rates were calculated by logistic regression. Variables with a p-value < 0.05 were considered statistically significant.

RESULTS

Of the 86, 81 schoolchildren completed the study. The prevalence of hookworm re-infection in the 4th and 6th months was 23.5% and 33.3%, respectively. Living with family members greater than five (p = .017), poor utilization of latrine (p = .008), infrequent shoe wear (p = .039), and participating in irrigation (p = .020) were the predictors significantly associated with hookworm re-infections.

CONCLUSIONS

The re-infection rate was high during the fourth and sixth months. Participating in irrigation, infrequent shoe wear, and poor latrine utilization were predictors of hookworm re-infection. Therefore, mass drug administration, regular shoe wearing, and health education should be advocated.