Soil-transmitted helminth infection, loss of education and cognitive impairment in school-aged children: A systematic review and meta-analysis

Tungiasis among children in Kenya is associated with poor nutrition status, absenteeism, poor school performance and high impact on quality of life

Tungiasis is a highly neglected tropical skin disease caused by the sand flea, Tunga penetrans. The flea burrows into the skin inducing a strong inflammatory response, leading to pain and mobility restrictions with potential impacts on quality of life. Few countries implement control efforts and there are few data on the impact of the disease to support policy decisions. We conducted a survey to determine the impact of tungiasis among primary school children across nine counties of Kenya. A total of 10,600 pupils aged 8 to 14 years were randomly selected from 97 primary schools and examined for tungiasis. For 81 cases and 578 randomly selected controls, anthropometric measurements were made, and school attendance and exam scores were collected from school records. Of those with tungiasis, 73 were interviewed regarding their quality of life using a tungiasis-specific instrument. Mixed effect ordered logistic and linear models were used to assess associations between disease status and impact variables. Compared to uninfected pupils, those with tungiasis had lower weight-for-age z-scores (adjusted β -0.41, 95% CI: -0.75-0.06, p = 0.020), missed more days of school the previous term (adjusted Incidence Rate Ratio: 1.49, 95% CI: 1.01-2.21, p = 0.046) and were less likely to receive a high score in mathematics (aOR 0.18, 95% CI: 0.08-0.40, p<0.001) and other subjects. Pupils with severe disease (clinical score >10) were four times more likely to experience severe pain than those with mild disease (OR 3.96, 95% CI: 1.35-11.64, p = 0.012) and a higher impact on their quality of life than those with mild disease (aOR 3.57, 95% CI: 1.17-10.8, p = 0.025) when adjusted for covariates. This study has demonstrated tungiasis has a considerable impact on children's lives and academic achievement. This indicates the need for integrated disease management for school-aged children to protect their physical and cognitive development and their future prospects.

Co-benefits from health and health systems to education

This review draws on over 70 studies spanning 2000 to 2023 to analyze the causal effect of health on educational outcomes. Health and health system interventions during the prenatal, infant, and childhood period impact longer-run educational attainment and performance. The magnitude of these effects is both statistically and economically significant, comparable in size to impacts on educational outcomes of interventions found in the literature. These impacts of health and health system interventions differ across gender and socioeconomic status, illustrating how health and health systems can exacerbate or mitigate educational inequalities. By showing the intertwined nature of health and education, this review highlights the importance of a comprehensive approach in policy-making that aligns with the Sustainable Development Goals.

Feasibility of delivering vitamin A supplementation (VAS) and deworming through routine community health services in Siaya County, Kenya: A cross-sectional study

Vitamin A deficiency and soil-transmitted helminth infection are serious public health problems in Kenya. The coverage of vitamin A supplementation and deworming medication (VASD) provided through mass campaigns is generally high, yet with a cost that is not sustainable, while coverage offered through routine health services is low. Alternative strategies are needed that achieve the recommended coverage of >80% of children twice annually and can be managed by health systems with limited resources. We undertook a study from September to December 2021 to compare the feasibility and coverage of VASD locally delivered by community health volunteers (CHV) ("intervention arm") to that achieved by the bi-annual Malezi Bora campaign event ("control arm"). This comparative cross-sectional study was conducted in sub-counties of Siaya County using both qualitative and quantitative methods. VASD were offered through the CHS in Alego Usonga and through Malezi Bora in Bondo Sub-County. Coverage was assessed by a post-event coverage survey among caregivers of children aged 6-59 months (n = 307 intervention; n = 318 control). Key informant interviews were conducted with n = 43 personnel across both modalities, and 10 focus group discussions were conducted with caregivers of children aged 6-59 months to explore knowledge, attitudes and perceptions of the two strategies. VAS coverage by CHV was 90.6% [95% CI: 87.3-93.9] compared to 70.4% [95% CI: 65.4-75.4] through the Malezi Bora, while deworming coverage was 73.9% [95% CI: 69.0-78.7] and 54.7% [95% CI: 49.2-60.2], respectively. With sufficient training and oversight, CHV can achieve superior coverage to campaigns.

Diagnosis of soil-transmitted helminth infections with digital mobile microscopy and artificial intelligence in a resource-limited setting

BACKGROUND

Infections caused by soil-transmitted helminths (STHs) are the most prevalent neglected tropical diseases and result in a major disease burden in low- and middle-income countries, especially in school-aged children. Improved diagnostic methods, especially for light intensity infections, are needed for efficient, control and elimination of STHs as a public health problem, as well as STH management. Image-based artificial intelligence (AI) has shown promise for STH detection in digitized stool samples. However, the diagnostic accuracy of AI-based analysis of entire microscope slides, so called whole-slide images (WSI), has previously not been evaluated on a sample-level in primary healthcare settings in STH endemic countries.

METHODOLOGY/PRINCIPAL FINDINGS

Stool samples (n = 1,335) were collected during 2020 from children attending primary schools in Kwale County, Kenya, prepared according to the Kato-Katz method at a local primary healthcare laboratory and digitized with a portable whole-slide microscopy scanner and uploaded via mobile networks to a cloud environment. The digital samples of adequate quality (n = 1,180) were split into a training (n = 388) and test set (n = 792) and a deep-learning system (DLS) developed for detection of STHs. The DLS findings were compared with expert manual microscopy and additional visual assessment of the digital samples in slides with discordant results between the methods. Manual microscopy detected 15 (1.9%) Ascaris lumbricoides, 172 (21.7%) Tricuris trichiura and 140 (17.7%) hookworm (Ancylostoma duodenale or Necator americanus) infections in the test set. Importantly, more than 90% of all STH positive cases represented light intensity infections. With manual microscopy as the reference standard, the sensitivity of the DLS as the index test for detection of A. lumbricoides, T. trichiura and hookworm was 80%, 92% and 76%, respectively. The corresponding specificity was 98%, 90% and 95%. Notably, in 79 samples (10%) classified as negative by manual microscopy for a specific species, STH eggs were detected by the DLS and confirmed correct by visual inspection of the digital samples.

CONCLUSIONS/SIGNIFICANCE

Analysis of digitally scanned stool samples with the DLS provided high diagnostic accuracy for detection of STHs. Importantly, a substantial number of light intensity infections were missed by manual microscopy but detected by the DLS. Thus, analysis of WSIs with image-based AI may provide a future tool for improved detection of STHs in a primary healthcare setting, which in turn could facilitate monitoring and evaluation of control programs.

Effectiveness of a School Intervention Based on Knowledge, Attitude, and Practice of Soil-Transmitted Helminths

More than 1.5 billion people are infected by soil-transmitted helminths (STHs) worldwide, comprising one of the world's most serious public health problems. School-age children are the most affected as a result of precarious hygienic habits, especially in economically poor areas that lack appropriate sanitation. Therefore, this study aimed to evaluate a didactic method via a health education approach as a complement to the school curriculum of the sixth-grade students of public schools, distributed among six cities in the state of São Paulo, Brazil. For this, a didactic booklet was elaborated with educational explanatory activities about worms, their life cycle, and how to avoid infections. The intervention was measured by the change caused by knowledge, attitude, and practice (KAP), in students before and after using the notebook, through a questionnaire with high validity and internal consistency. Schools were assigned randomly into intervention and control groups, receiving both the didactic material and the questionnaires, versus the questionnaires only, respectively. The results were submitted to an analysis of covariance that revealed a significant difference pre- and postintervention for knowledge (P < 0.001), with greater means (0.54) compared with the control group (0.44); attitude (P < 0.005), with respective means of 0.56 versus 0.48; and practice (P < 0.001), with means of 0.75 versus 0.57. These findings set the didactic material as a potential tool to complement the school curriculum through KAP without disrupting the teaching system, in addition to assisting teachers in health education at schools aiming to prevent children's infections by STHs.

Protocol for spatial prediction of soil transmitted helminth prevalence in the Western Pacific region using a meta-analytical approach

BACKGROUND

Soil transmitted helminth (STH) infections are estimated to impact 24% of the world's population and are responsible for chronic and debilitating morbidity. Disadvantaged communities are among the worst affected and are further marginalized as infection prevalence fuels the poverty cycle. Ambitious targets have been set to eliminate STH infections, but accurate epidemiological data will be required to inform appropriate interventions. This paper details the protocol for an analysis that aims to produce spatial prediction mapping of STH prevalence in the Western Pacific Region (WPR).

METHODS

The protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol (PRISMA-P) guidelines. The study design will combine the principles of systematic review, meta-analysis, and geospatial analysis. Systematic searches will be undertaken in PubMed, Scopus, ProQuest, Embase, and Web of Science for studies undertaken post 2000, to identify surveys that enable the prevalence of human STH infection within the WPR to be calculated. Covariate data for multivariable analysis will be obtained from publicly accessible sources. Survey data will be geolocated, and STH prevalence and covariates will be linked to produce a spatially referenced dataset for analysis. Bayesian model-based geostatistics will be used to generate spatially continuous estimates of STH prevalence mapped to a resolution of 1 km2. A separate geospatial model will be constructed for each STH species. Predictions of prevalence will be made for unsampled locations and maps will be overlaid for each STH species to obtain co-endemicity maps.

DISCUSSION

This protocol facilitates study replication and may be applied to other infectious diseases or alternate geographies. Results of the subsequent analysis will identify geographies with high STH prevalence's and can be used to inform resource allocation in combating this neglected tropical disease.

TRIAL REGISTRATION

Open Science Framework: osf.io/qmxcj.

Effectiveness of one and two doses of ivermectin mass drug administration in reducing the prevalence and intensity of soil-transmitted helminth (STH) infections in Western Province, Solomon Islands: a cluster-randomised, before-after analysis

Background

Ivermectin mass drug administration (MDA) is effective for controlling onchocerciasis and scabies, with evidence supporting its role in some species of soil-transmitted helminth (STH) infections. In the context of RISE, a cluster-randomised trial for scabies, this study evaluated the effectiveness of ivermectin MDA in reducing STH burden in the Western Province of Solomon Islands.

Methods

Twenty villages were randomised 1:1 to receive ivermectin MDA as one dose (IVM-1) or two doses (IVM-2) for scabies. The effectiveness of one and two doses in reducing STH prevalence and intensity was evaluated before (May 2019) and 21 months after (February 2021) MDA in May 2019. All residents aged 12 months or older in the study villages were eligible to participate and provide stool specimens. Species-specific STH infection and intensity were assessed using quantitative PCR. We compared prevalence and intensity of infection between baseline and 21 months in each intervention arm individually using cluster-level analysis (adjusted for clustering) and individual-level analysis (adjusted for sex, age, and clustering). The primary outcomes were the prevalence risk difference (RD) from the cluster-level analysis, and the change in adjusted odds of infection from the individual-level analysis. Secondary outcomes included change in incident rates of mean eggs per gram (epg) of stool from baseline to 21 months, relative risk difference in prevalence and relative change in odds of infection between arms at 21 months. Sex data (male/female) were self-reported.

Findings

Overall, STH infection was assessed in 830 participants from 18 villages at baseline and 1172 from 20 villages at follow-up. Females represented 58% (n = 478) of the sample at baseline and 59% (n = 690) at follow-up. We observed a reduction in Strongyloides spp. prevalence following two doses of ivermectin MDA in the cluster-level analysis from 7.0% (32/458 participants) to 1.2% (8/674 participants), corresponding to a RD of -0.07 (95% CI -0.14 to -0.01, p = 0.036), and in the individual-level analysis (OR 0.11, 95% CI 0.04-0.33, p < 0.001). T. trichiura prevalence decreased following one dose from 19.4% (74/372 participants) to 11.7% (56/505 participants) (OR 0.44, 95% CI 0.26-0.73, p = 0.0040), while egg count reduced in both arms (IVM-1: IRR 0.28, 95% CI 0.11-0.70, p = 0.0070; IVM-2: IRR 0.18, 95% CI 0.08-0.40, p < 0.001), in the individual-level analysis. We did not detect a significant difference in effect measures between the one- and two-dose arms for any species after 21 months.

Interpretation

Our study highlights the long-term benefits of ivermectin MDA in reducing the burden of Strongyloides spp. and T. trichiura. STH control programs should leverage the geographical overlap of NTDs, existing drug distribution channels, and broad-spectrum agents.

Funding

The National Health and Medical Research Council of Australia.

Anthelmintic resistance in soil-transmitted helminths: One-Health considerations

The One-Health approach recognizes the intricate connection between human, animal, and environmental health, and that cooperative effort from various professionals provides comprehensive awareness and potential solutions for issues relating to the health of people, animals, and the environment. This approach has increasingly gained appeal as the standard strategy for tackling emerging infectious diseases, most of which are zoonoses. Treatment with anthelmintics (AHs) without a doubt minimizes the severe consequences of soil-transmitted helminths (STHs); however, evidence of anthelmintic resistance (AR) development to different helminths of practically every animal species and the distinct groups of AHs is overwhelming globally. In this regard, the correlation between the application of anthelmintic drugs in both human and animal populations and the consequent development of anthelmintic resistance in STHs within the context of a One-Health framework is explored. This review provides an overview of the major human and animal STHs, treatment of the STHs, AR development and drug-related factors contributing towards AR, One-Health and STHs, and an outline of some One-Health strategies that may be used in combating AR.

Prevalence and Determinants of Geohelminthiasis among School-Age Children in Jimma City, Ethiopia

School-age children (SAC) are at a higher risk of geohelminth or soil-transmitted helminth (STH) infections due to their practice of walking and playing barefoot, lack of adequate sanitary facilities, and poor personal hygiene. In Ethiopia, periodic deworming has been implemented since 2013 with the aim of interrupting the transmission of STH in children by 2025. To evaluate the likely success of such a control program, it is crucial to monitor the transmission of STH, especially in peri-urban settings where environmental sanitation is modest. The aim of this study was to determine the prevalence and determinants of STH infections among SAC in peri-urban areas of Jimma City, Southwestern Ethiopia. A community-based cross-sectional study was conducted in five peri-urban Kebeles of Jimma City from July to September, 2021. Systematic random sampling was used to select 522 households with at least one child, and 478 children (5-15 years old) were recruited randomly from the households. Data on sociodemographic and potential risk factors were collected using a structured questionnaire. Stool samples from each study participant were collected and examined microscopically using the Kato-Katz technique. Multivariate logistic regression model was used to identify risk factors associated with STH infections. The prevalence of any STH among SAC was 23.4%, with Ascaris lumbricoides being the predominant STH species (15.7%), followed by Trichuris trichiura (9%) and hookworm (2.1%). Most (86.6%) of the STH-positive SAC had a single infection and a light infection intensity (88.2%), with a mean intensity of 367.4 eggs per gram. Location of Kebele (AOR = 2.73; 95% CI: 1.21-6.16, p=0.016), lack of hand washing after defecation (AOR = 6.39; 95% CI: 3.16-12.95, p < 0.001), untrimmed fingernails (AOR = 2.65; 95% CI: 1.56-4.51, p < 0.001), and lack of previous deworming (AOR = 2.90; 95% CI: 1.47-5.74, p=0.002) were significant predictors for STH infections among SAC. In conclusion, the study revealed that STH infections are significant health problem in the peri-urban areas of Jimma City. Strengthening periodic deworming and improving children's hygiene through health education are required to reduce the transmission.

Soil-transmitted helminths: A critical review of the impact of co-infections and implications for control and elimination

Researchers have raised the possibility that soil-transmitted helminth (STH) infections might modify the host's immune response against other systemic infections. STH infections can alter the immune response towards type 2 immunity that could then affect the likelihood and severity of other illnesses. However, the importance of co-infections is not completely understood, and the impact and direction of their effects vary considerably by infection. This review synthesizes evidence regarding the relevance of STH co-infections, the potential mechanisms that explain their effects, and how they might affect control and elimination efforts. According to the literature reviewed, there are both positive and negative effects associated with STH infections on other diseases such as malaria, human immunodeficiency virus (HIV), tuberculosis, gestational anemia, pediatric anemia, neglected tropical diseases (NTDs) like lymphatic filariasis, onchocerciasis, schistosomiasis, and trachoma, as well as Coronavirus Disease 2019 (COVID-19) and human papillomavirus (HPV). Studies typically describe how STHs can affect the immune system and promote increased susceptibility, survival, and persistence of the infection in the host by causing a TH2-dominated immune response. The co-infection of STH with other diseases has important implications for the development of treatment and control strategies. Eliminating parasites from a human host can be more challenging because the TH2-dominated immune response induced by STH infection can suppress the TH1 immune response required to control other infections, resulting in an increased pathogen load and more severe disease. Preventive chemotherapy and treatment are currently the most common approaches used for the control of STH infections, but these approaches alone may not be adequate to achieve elimination goals. Based on the conclusions drawn from this review, integrated approaches that combine drug administration with water, sanitation and hygiene (WASH) interventions, hygiene education, community engagement, and vaccines are most likely to succeed in interrupting the transmission of STH co-infections. Gaining a better understanding of the behavior and relevance of STH co-infections in the context of elimination efforts is an important intermediate step toward reducing the associated burden of disease.

Assessing the knowledge, attitudes, practices, and perspectives of stakeholders of the deworming program in rural Rwanda

BACKGROUND

Worm infections are among the most prevalent neglected tropical diseases worldwide. Schistosomiasis and soil-transmitted helminths infections, most common worm infections affecting Rwandan school-aged children, are addressed by the national deworming program since 2014. To date, no published studies have assessed the knowledge, attitudes, and practices of the key implementers of the national deworming program conducted at village and school level in Rwanda. This study aimed to assess key stakeholders' knowledge, attitudes, practices, and perspectives about the decentralized national deworming program.

METHODS/PRINCIPAL FINDINGS

We carried out a quantitative, cross-sectional study with complementary in-depth interviews in two districts of Rwanda in June 2021. From the 852 surveyed community health workers and teachers, 54.1% had a knowledge score considered good (≥80%). The mean knowledge score was 78.04%. From the multivariate analysis, lack of training was shown to increase the odds of having poor knowledge (OR 0.487, 95% CI: 0.328-0.722, p <0.001). The in-depths interviews revealed poor water access and hesitance from caregivers as perceived challenges to the success of the deworming program.

CONCLUSION

Our findings demonstrate the importance of training community health workers and schoolteachers on worm infections as they are the key implementers of the deworming program. This would enhance their capacity to provide health education and sensitization on misconceptions and misinformation towards deworming. Moreover, research is needed to assess the impact of poor access to water, sanitation and hygiene facilities on the prevalence of worm infections in Rwanda.

Association between altered cognition and Loa loa microfilaremia: First evidence from a cross-sectional study in a rural area of the Republic of Congo

BACKGROUND

Individuals with high Loa loa microfilarial densities are at risk of developing severe encephalopathy after administration of antiparasitic drugs. Apart from this finding, loiasis is considered benign with no effect on brain function. However, recent epidemiological data suggest an increased mortality and morbidity in L. loa infected individuals, underscoring the importance of studies on the possible neurological morbidity associated with loiasis.

METHODOLOGY

Using MoCA tests and neurological ultrasounds, we conducted a cross-sectional study to assess cognitive alteration in a population living in a rural area endemic for loiasis in the Republic of Congo. Fifty individuals with high microfilarial densities (MFD) were matched on sex, age and residency with 50 individuals with low MFD and 50 amicrofilaremic subjects. Analyses focused on individuals with MoCA scores indicating an altered cognition (i.e. < 23/30) and on the total MoCA score according to Loa loa MFD, sociodemographic characteristics and neurological ultrasound results.

PRINCIPAL FINDINGS

MoCA scores were very low in the studied population (mean of 15.6/30). Individuals with more than 15,000 microfilariae per milliliter of blood (mean predicted score:14.0/30) are more than twenty times more likely to have an altered cognition, compared to individuals with no microfilaremia (mean predicted score: 16.3/30). Years of schooling were strongly associated with better MoCA results. Extracranial and intracranial atheroma were not associated with L. loa MFD.

CONCLUSION/SIGNIFICANCE

Loaisis microfilaremia is probably involved in cognitive impairment, especially when the MFD are high. These results highlight the urgent need to better understand loaisis-induced morbidity. Further studies investigating neurological morbidity of loiasis are needed.

Impact of helminth-microbiome interactions on childhood health and development-A clinical perspective

Humans have co-existed with parasites for virtually the entirety of our existence as a species. Today, nearly one third of the human population is infected with at least one helminthic species, most of which reside in the intestinal tract, where they have co-evolved alongside the human gut microbiota (GM). Appreciation for the interconnected relationship between helminths and GM has increased in recent years. Here, we review the evidence of how helminths and GM can influence various aspects of childhood development and the onset of paediatric diseases. We discuss the emerging evidence of how many of the changes that parasitic worms inflict on their host is enacted through gut microbes. In this light, we argue that helminth-induced microbiota modifications are of great importance in both facing the global challenge of overcoming parasitic infections, and in replicating helminthic protective effects against inflammatory diseases. We propose that deepening our knowledge of helminth-microbiota interactions will uncover novel, safer and more effective therapeutic strategies in combatting an array of childhood disorders.

Red palm olein-enriched biscuit supplementation lowers Ascaris lumbricoides reinfection at 6-month after anthelmintic treatment among schoolchildren with vitamin A deficiency (VAD)

Notwithstanding the global efforts made to control intestinal parasitic infections, soil-transmitted helminth (STH) infections are still one of the most prevalent infections globally, especially in developing countries. A double-blinded, randomized controlled trial was conducted on 343 primary schoolchildren (8-12 years old) with vitamin A deficiency (VAD) in rural areas of Malaysia to investigate the effects of red palm olein (RPO)-enriched biscuits on STH reinfection rates and infection intensities. The effects of the RPO-enriched biscuits (experimental group, n = 153) and palm olein (PO)-enriched biscuits (control group, n = 190), were assessed at 3- and 6-month after the administration of complete triple-dose albendazole (one dose of 400 mg for three consecutive days). The overall STH infection rate at baseline was recorded at 65.6%. At 6-month, a significantly lower reinfection rate of A. lumbricoides was observed in the experimental group (35.3%) compared to the control group (60.0%) (P< 0.05), and a significant reduction in fecal egg count (epg) of A. lumbricoides was observed in the experimental group from baseline (P< 0.001), but no significant reduction was observed in the control group. No significant differences in the reduction of infection intensities of T. trichiura and hookworm were observed between experimental and control groups at 3- and 6-month (P>0.05). These findings suggest the potential beneficial effects of RPO-enriched biscuit supplementation on the reinfection of A. lumbricoides, which could be attributed to its high carotenoids content by enhancing host immune response and mucosal epithelium integrity. However, further studies are warranted to confirm whether RPO supplementation could result in similar parasite-specific beneficial effects in other community settings, as well as to explore the underlying mechanisms.

A review on innovative optical devices for the diagnosis of human soil-transmitted helminthiasis and schistosomiasis: from research and development to commercialization

Diagnosis of soil-transmitted helminth (STH) and schistosome infections relies largely on conventional microscopy which has limited sensitivity, requires highly trained personnel and is error-prone. Rapid advances in miniaturization of optical systems, sensors and processors have enhanced research and development of digital and automated microscopes suitable for the detection of these diseases in resource-limited settings. While some studies have reported proof-of-principle results, others have evaluated the performance of working prototypes in field settings. The extensive commercialization of these innovative devices has, however, not yet been achieved. This review provides an overview of recent publications (2010–2022) on innovative field applicable optical devices which can be used for the diagnosis of STH and schistosome infections. Using an adapted technology readiness level (TRL) scale taking into account the WHO target product profile (TPP) for these diseases, the developmental stages of the devices were ranked to determine the readiness for practical applications in field settings. From the reviewed 18 articles, 19 innovative optical devices were identified and ranked. Almost all of the devices (85%) were ranked with a TRL score below 8 indicating that, most of the devices are not ready for commercialization and field use. The potential limitations of these innovative devices were discussed. We believe that the outcome of this review can guide the end-to-end development of automated digital microscopes aligned with the WHO TPP for the diagnosis of STH and schistosome infections in resource-limited settings.

Prevalence of malaria-helminth co-infections among children living in a setting of high coverage of standard interventions for malaria and helminths: Two population-based studies in Senegal

Background

Concurrent infections of Plasmodium falciparum with Soil Transmitted Helminths (STH) and Schistosoma spp are still a major public health problem among children living in Sub-Saharan Africa. We conducted two prospective studies among children living in urban and rural settings of Senegal, where control programmes for malaria, STH and schistosomiasis have been sustained, to determine the prevalence of malaria-helminth co-infection.

Methods

We enrolled 910 children aged 1-14 years from Saraya and Diourbel districts of Senegal in June and November 2021, respectively. We collected finger-prick blood samples from the children for malaria parasite detection using microscopy and PCR methods. Stool samples were also collected and Kato-Katz and PCR methods were used to detect STH and S. mansoni; and Merthiolate-iodine-formalin (MIF) test for other intestinal protozoans. Urine samples were analyzed using a filtration test, Point of Care Circulating Cathodic Antigens (POC-CCA) and PCR methods for detection of S. haematobium. Statistical analyses were performed to compare the continuous and categorical variables across the two study sites and age groups, as well as using the adjusted Odds ratios (aOR) to explore risk factors for malaria-helminth co-infections.

Results

The overall prevalence of polyparasitism with P. falciparum, STH, S. haematobium and S. mansoni among children in the two study sites was 2.2% (20/910) while prevalence of P. falciparum-S. haematobium co-infection was 1.1% (10/910); P. falciparum-S. mansoni 0.7% (6/910) and P. falciparum with any intestinal protozoan 2.4% (22/910). Co-infection was slightly higher among 5-14 year old children (17/629, 2.7%; 95% CI: 1.43-3.97) than 1-4 years (3/281, 1.1%; 95% CI: -0.12-2.32) and, in boys (13/567, 2.3%; 95% CI: 1.27-3.96) than girls (7/343, 2.1%; 95% CI: 0.52-3.48). Children aged 5-14 years (aOR = 3.37; 95% CI: 0.82-13.77, p = 0.09), who were boys (aOR = 1.44; 95% CI: 0.48-4.36, p = 0.51) and lived in Saraya (aOR = 1.27; 95% CI: 0.24-6.69, p = 0.77) had a higher risk of malaria-helminth co-infection than other age group, in girls and those who lived in Diourbel. Living in houses with spaces between the walls and roofs as well as frequent contacts with water during swimming were statistically significant risk factors for malaria-helminth co-infection.

Conclusions

The prevalence of malaria-helminth co-infection is low in two districts in Senegal, possibly due to sustained implementation of effective control measures for malaria and NTDs. These findings could help to develop and implement strategies that would lead to elimination of malaria and helminths in the study areas.

Micronutrients deficiencies and its correlation with the soil-transmitted helminthic infections among children and non-pregnant women in Nepal: findings from Nepal national micronutrient status survey

Despite having a high risk of soil-transmitted helminths (STHs) infection, no national level study has been conducted to assess incidence and correlates of STHs in Nepal. Thus, we hypothesized that micronutrients and social status are linked with incidence of STHs infection among 6-59 months children and 15-49 years non-pregnant women in Nepal and Kato-Katz technique was adopted to measure the type and intensity of STHs infections using fresh stool specimens and venous blood was used to examine micronutrients biomarkers. Anthropometric measurements such as height and weight, sociodemographic and health status were determined using structured questionnaire. Logistic regression was used to assess unadjusted and adjusted odds ratio (AOR) and the 95% CIs of ORs. The bivariate association of STHs was assessed with the covariates variables. Overall, 12% children and 19% non-pregnant women had STHs infection; A. lumbricoides was the predominant helminth in both study participants. In multivariate model; age, ethnicity, anaemia and zinc deficiency were associated with STHs infections in children. Similarly, higher odds of STHs occurrence was observed among non-pregnant women with vitamin A deficiency. Findings from this study suggest that high-risk population, with a focus on those of lower socioeconomic status should be on priority of deworming program, nutrition intervention, and mass administration of preventive chemotherapy and sanitation champions supplement to reduce the STHs infections in Nepal.

School water, sanitation, and hygiene (WaSH) intervention to improve malnutrition, dehydration, health literacy, and handwashing: a cluster-randomised controlled trial in Metro Manila, Philippines

BACKGROUND

The impacts of multicomponent school water, sanitation, and hygiene (WaSH) interventions on children's health are unclear. We conducted a cluster-randomized controlled trial to test the effects of a school WaSH intervention on children's malnutrition, dehydration, health literacy (HL), and handwashing (HW) in Metro Manila, Philippines.

METHODS

The trial lasted from June 2017 to March 2018 and included children, in grades 5, 6, 7, and 10, from 15 schools. At baseline 756 children were enrolled. Seventy-eight children in two clusters were purposively assigned to the control group (CG); 13 clusters were randomly assigned to one of three intervention groups: low-intensity health education (LIHE; two schools, n = 116 children), medium-intensity health education (MIHE; seven schools, n = 356 children), and high-intensity health education (HIHE; four schools, n = 206 children). The intervention consisted of health education (HE), WaSH policy workshops, provision of hygiene supplies, and WaSH facilities repairs. Outcomes were: height-for-age and body mass index-for-age Z scores (HAZ, BAZ); stunting, undernutrition, overnutrition, dehydration prevalence; HL and HW scores. We used anthropometry to measure children's physical growth, urine test strips to measure dehydration, questionnaires to measure HL, and observation to measure HW practice. The same measurements were used during baseline and endline. We used multilevel mixed-effects logistic and linear regression models to assess intervention effects.

RESULTS

None of the interventions reduced undernutrition prevalence or improved HAZ, BAZ, or overall HL scores. Low-intensity HE reduced stunting (adjusted odds ratio [aOR] 0.95; 95% CI 0.93 to 0.96), while low- (aOR 0.57; 95% CI 0.34 to 0.96) and high-intensity HE (aOR 0.63; 95% CI 0.42 to 0.93) reduced overnutrition. Medium- (adjusted incidence rate ratio [aIRR] 0.02; 95% CI 0.01 to 0.04) and high-intensity HE (aIRR 0.01; 95% CI 0.00 to 0.16) reduced severe dehydration. Medium- (aOR 3.18; 95% CI 1.34 to 7.55) and high-intensity HE (aOR 3.89; 95% CI 3.74 to 4.05) increased observed HW after using the toilet/urinal.

CONCLUSION

Increasing the intensity of HE reduced prevalence of stunting, overnutrition, and severe dehydration and increased prevalence of observed HW. Data may be relevant for school WaSH interventions in the Global South. Interventions may have been more effective if adherence was higher, exposure to interventions longer, parents/caregivers were more involved, or household WaSH was addressed.

TRIAL REGISTRATION NUMBER

DRKS00021623.

Effect of Schistosoma haematobium infection on the cognitive functions of preschool age children and benefits of treatment from an endemic area in Zimbabwe

Background

Schistosomiasis is known to affect the cognitive functions of children, however, but there is paucity of information on its impact on early childhood development in developing countries where the disease is endemic. This study aimed at determining the effects of schistosomiasis due to Schistosoma haematobium on early childhood development in children below 5 years old from Murewa District, Zimbabwe, including the benefits of treatment.

Methods

Preschool age children (PSAC) under the age of 5 years were screened at baseline and at 6 months post-treatment for S. haematobium infections diagnosed using the urine filtration method. Cognitive domains were assessed using the Griffith Mental Developmental Scales III on 136 PSAC. Multivariate logistic regression was used to determine the level of association between S. haematobium infection and performance in the cognitive domains adjusting for confounding factors (i.e. nutrition, hemoglobin levels, gender and age). Median Development Quotient scores of each cognitive domain at baseline and at 6 months post-treatment were compared and quantified.

Results

After adjusting for confounding factors, PSAC infected with S. haematobium had greater odds of having lower scores in the Foundation of Learning Domain (OR = 3.9, p = 0.008), Language and Communication Domain (OR = 3.2, p = 0.017), Eye-Hand Coordination Domains (OR = 10.7, p = 0.001), Personal-Social-Emotional Domain (19.3, p = 0.001) and in the Overall General Development Domain (7.2, p = 0.011). Improvement of cognitive performance was observed at 6 months post treatment in the following Domains; Language and Communication Domain (p = 0.003), Eye-Hand Coordination Domain (p = 0.02) and General Development Domain (p = 0.006).

Conclusion

The study showed that S. haematobium infection in PSAC is associated with lower cognitive scores in the Foundation of Learning, Language and Communication, Eye-Hand Coordination, Personal-Social-Emotional and in the Overall General Development domains. Our results strengthen the call for inclusion of PSAC in routine deworming programs for the control of urinary schistosomiasis and the need to develop locally validated tools to monitor early child development in endemic areas where resources are limited.

Prevalence and intensity of soil-transmitted helminth infections and associated risk factors among household heads living in the peri-urban areas of Jimma town, Oromia, Ethiopia: A community-based cross-sectional study

Background

Ethiopia has set national targets for eliminating soil-transmitted helminths (STH) as public health problems by 2020 and for breaking their transmission by 2025 using periodic mass treatment of children in endemic areas. However, the status of STH infection among the adults living in the same communities remains unknown. The aim of this study, therefore, was to determine the prevalence and intensity of STH infections and associated factors among the household heads in the peri-urban areas of Jimma town, Oromia, Ethiopia.

Methods

A community-based cross-sectional study was conducted in five peri-urban kebeles (smallest administrative unit in Ethiopia) of Jimma town from May to July 2021. A semi-structured questionnaire was used to collect data on socio-demographic and predisposing factors. The Kato-Katz concentration technique was utilized to detect and quantify the STH in stool samples. Both bivariate and multivariate analyses were done. P-value <0.05 was considered statistically significant.

Results

A total of 376 household heads (19.9% women and 80.1% men) from peri-urban areas were included in the study. The overall STH prevalence was 18.1% (95% CI: 14.6–22.1) with A. lumbricoides being the predominant species (11.4%) followed by T. trichiura (7.2%) and hookworm (2.1%). Most of the STH positive household heads had single infections (85.3%) and light-intensity infections (88.5%). Wealth status (AOR = 2.7; 95% CI: 1.31–5.50, P = 0.007), hand washing habits before meals (AOR = 7.07; 95% CI: 1.79–27.88, p = 0.005), fingernails status (AOR = 2.99; 95% CI: 1.59–5.65, p = 0.001), and toilet facility type (AOR = 2.06; 95% CI: 1.13–3.76, p = 0.017) were found to have statistically significant associations with the STH infection.

Conclusion

The findings of this study showed a nearly moderate level of STH prevalence among household heads in the peri-urban community. This could serve as an important reservoir for reinfection of the treated children and other at-risk groups in the community.

Schistosoma mansoni and soil-transmitted helminths among schoolchildren in An-Nadirah District, Ibb Governorate, Yemen after a decade of preventive chemotherapy

The Ministry of Public Health in Yemen continues the implementation of school and community–based preventive chemotherapy with praziquantel and albendazole for the control and elimination of schistosomiasis and soil-transmitted helminths (STH). The latest remapping to update the distribution of schistosomiasis and STH was conducted seven years ago. This study aimed to estimate the prevalence, intensity and associated risk factors of Schistosoma mansoni and STH among schoolchildren in An-Nadirah District, Ibb Governorate, Yemen. A cross-sectional study was carried out among schoolchildren aged 6–15 years in four selected schools. Biological, demographic, socioeconomic and environmental data were collected using a pre-tested questionnaire. S. mansoni and STH eggs were detected and counted by the microscopic examination of Kato-Katz fecal smears. Out of 417 schoolchildren, 17.0% were infected with at least one intestinal helminth. Prevalence of S. mansoni and STH were 6.5% and 9.1%, respectively. The most prevalent parasite among STH was Ascaris lumbricoides (8.4%). Unemployed fathers (Adjusted Odds Ratio (AOR) = 3.2; 95% Confidence interval (CI): 1.23, 8.52; P = 0.018), eating exposed food (AOR: 2.9; 95%CI = 1.24, 6.89; P = 0.014), not washing hands before eating and after defecation (AOR: 4.8; 95%CI = 1.77, 12.81; P = 0.002), and schools located close to water stream (AOR: 22.1; 95%CI = 5.12, 95.46; P <0.001) were independent risk factors of ascariasis. Swimming in ponds/stream (AOR: 3.9; 95%CI = 1.63, 9.55; P = 0.002), and schools close to the stream (AOR: 24.7; 95%CI = 3.05, 200.07; P = 0.003) were independent risk factors of intestinal schistosomiasis. The present study does not indicate a reduction in the prevalence of intestinal schistosomiasis in this rural area since the latest remapping conducted in 2014, although ascariasis was reduced by half. The prevalence of the two parasites was highly focal in areas close to the valley, suggesting a significant role of the stream in sustaining and accelerating the parasitic infection. Children practicing swimming and having poor hygienic practices were at high exposure to S. mansoni and A. lumbricoides, respectively. Water, Sanitation and Hygiene intervention, school–based health education, and snail control, in addition to mass drug administration, will help in the interruption of transmission of schistosomiasis and STH.

Efficacy of triple dose albendazole treatment for soil-transmitted helminth infections

In Malaysia, soil-transmitted helminth (STH) infections still persist among indigenous communities. In the past, local studies have focused mostly on epidemiologic aspects of STH infections with a scarcity of information on the efficacy of deworming treatment. The present study consisted of 2 phases: a cross-sectional phase on current epidemiological status and risk factors of STH infections and a longitudinal study over 6 weeks on triple dose albendazole efficacy against STH infections. A total of 253 participants were recruited at baseline and a pre-tested questionnaire was administered to obtain information on socio-demographics, environmental and behavioural risk factors. Stool samples were evaluated using a modified Kato-Katz technique. Cure rate (CR) and egg reduction rate (ERR) were assessed at 3 weeks following a 3-day course of 400mg albendazole treatment and infection status were observed again at 6 weeks. Baseline positivity of trichuriasis, ascariasis and hookworm infections were 56.1%, 11.9% and 20.2%, respectively. Multivariate analysis showed age below 18 years old (P = 0.004), without latrine in house (P = 0.042) and indiscriminate defecation (P = 0.032) were associated with STH infections. In the longitudinal study (N = 89), CR for trichuriasis was 64.6%, while CR of 100% was observed for both ascariasis and hookworm. ERR was above 90% for all three STH species. A rapid increased of Trichuris trichiura egg output was observed at 6 weeks. In conclusion, STH infections are highly prevalent among indigenous communities. Children and teenagers, poor sanitation and hygiene behaviour were determinants for STH infections. Triple dose albendazole is found to be efficacious against Ascaris lumbricoides and hookworm infections but has moderate curative effect with high ERR against T. trichiura. Although triple dose albendazole regimen has logistic challenges and may not be a routine option, consideration of this treatment regime may still be necessary in selective communities to reduce high intensity of T. trichiura infection.

Safety of Praziquantel and Albendazole Coadministration for the Control and Elimination of Schistosomiasis and Soil-Transmitted Helminths Among Children in Rwanda: An Active Surveillance Study

Introduction

School-based preventive chemotherapy (Deworming) with praziquantel and albendazole to control and eliminate schistosomiasis and soil-transmitted helminths as public health problems is recommended by the World Health Organization (WHO). Safety monitoring during mass drug administration (MDA) is imperative but data from sub-Saharan Africa are scarce.

Objective

The aim of this active safety surveillance study was to identify the incidence, type, severity, and risk factors for adverse events (AEs) following mass administration of praziquantel and albendazole.

Methods

Overall, 8037 school children aged 5–15 years in Rwanda were enrolled. Baseline sociodemographic, medical history and any pre-existing clinical symptoms were recorded. Participants received a single dose of praziquantel and albendazole during MDA. AEs were actively monitored on days 1, 2, and 7 post MDA.

Results

Overall, 3196 AEs were reported by 1658 children; 91.3%, 8.4%, and 0.3% of the AEs were mild, moderate, and severe, respectively, and most resolved within 3 days. Headache (21%), dizziness or fainting (15.2 %), nausea (12.8%) and stomach pain (12.2%) were the most common AEs. The overall cumulative incidence of experiencing at least one type of AE was 20.6% (95% confidence interval [CI] 19.7–21.5%), being significantly higher (p < 0.001) in children with pre-MDA clinical events (27.5%, 95% CI 25.4–29.6%) than those without (18.7%, 95% CI 17.7–19.7%). Females, older age, having pre-MDA events, types of food taken before MDA and taking two or more praziquantel tablets were significant predictors of AEs.

Conclusions

Praziquantel and albendazole MDA is safe and well-tolerated; however, one in five children experience transient mild to moderate, and in few cases severe, AEs. The incidence of AEs varies significantly between sex and age groups. Pharmacovigilance in the MDA program is recommended for timely detection and management of AEs.

Intestinal Helminth Infection, Anemia, Undernutrition and Academic Performance among School Children in Northwestern Ethiopia

This study examined the prevalence and intensity of intestinal helminth infections and their association with anemia, undernutrition, and academic performance among school children in Maksegnit, northwestern Ethiopia. A total of 1205 school children, who attended Maksegnit Number Two Elementary School between May and July 2021, participated in this study. To determine helminth infection status, two thick Kato–Katz slides were examined for each child. Hemoglobin level was measured using a HemoCue machine. Academic performance was assessed using the mean score of all subjects children have taken for the Spring 2020/2021 academic term. Out of 1205 children examined, 45.4% were infected with at least one helminth species, 7.9% were anemic, and 35.8% were undernourished. The means for hemoglobin level and z-scores of weight for age, height for age, body mass index for age, and academic scores were lower among helminth-infected children than the uninfected. Children infected with intestinal helminths showed higher odds of anemia than those uninfected with helminths. In conclusion, there was a moderate prevalence of intestinal helminth infection and undernutrition among school children in Maksegnit. Intestinal helminth infection could increase the risk of anemia, undernutrition, and poor academic performance.

Evaluation of a Physical Activity and Multi-Micronutrient Intervention on Cognitive and Academic Performance in South African Primary Schoolchildren

Executive functions (EFs) are essential for optimal academic development. Appropriate nutrition and physical activity (PA) have been shown to facilitate optimal cognitive development. Therefore, this study examined whether a 12-week school-based PA and multi-micronutrient supplementation (MMNS) intervention would improve cognitive and academic performance. A cluster-randomized controlled trial (RCT) was conducted. Children from four schools located in a peri-urban area of South Africa were randomly assigned to (i) PA + MMNS, (ii) PA + placebo, (iii) MMNS or (iv) placebo. Information processing and inhibitory control were measured with a computerized Flanker task. End-of-year results provided insight into academic achievement. Anthropometric measures were used to determine nutritional status. Data were analyzed with linear mixed-models, adjusting for baseline scores, school classes and age; 932 children (458 girls (49.1%), M_age (mean age) = 8.42 ± 1.94 years) completed baseline and post-intervention assessments. Cognitive performance improved among all four groups, with no significant group × time effects. For academic achievement, there was no significant interaction effect between the combined intervention group and placebo. We encourage future studies in this neglected area in order to determine the most optimal design of school-based nutrition and PA programs to enhance overall cognitive performance.

Evidence of reduced academic performance among schoolchildren with helminth infection

Background

Soil-transmitted helminths (STHs) pose a formidable health risk to school-age children in resource-limited settings. Unfortunately, mass deworming campaigns have been derailed since the onset of the coronavirus disease 2019 pandemic. The present study assessed the cross-sectional associations between STHs, nutritional status and academic performance of schoolchildren in the Banda District of Ghana.

Methods

Schoolchildren (5–16 y of age; n=275) were recruited through both school and household visits by community health workers using a multistage cluster sampling technique. In addition to school microscopy, anthropometric records were also taken.

Results

The prevalence of geohelminthiasis was 40.4% (95% confidence interval 34.6 to 46.2). STHs targeted for elimination by the World Health Organization and national programmes were detected among schoolchildren. Children with intestinal parasite infection (53.7 [standard deviation {SD} 11.5]) had lower mean academic scores compared with uninfected children (59.6 [SD 16.9]) (p=0.034). In multiple regression analysis, intestinal parasite infection status and z-scores for weight-for-age showed a collective significant effect on the academic score (F₁₁₁₇=8.169, p<0.001, R²=0.125).

Conclusions

Schoolchildren with STHs had poorer academic performance compared with uninfected children, despite their nutritional status. In addition to school feeding programmes, school-based mass drug administration campaigns may be critical for improving learning outcomes in young schoolchildren.

The Road to Elimination: Current State of Schistosomiasis Research and Progress Towards the End Game

The new WHO Roadmap for Neglected Tropical Diseases targets the global elimination of schistosomiasis as a public health problem. To date, control strategies have focused on effective diagnostics, mass drug administration, complementary and integrative public health interventions. Non-mammalian intermediate hosts and other vertebrates promote transmission of schistosomiasis and have been utilized as experimental model systems. Experimental animal models that recapitulate schistosomiasis immunology, disease progression, and pathology observed in humans are important in testing and validation of control interventions. We discuss the pivotal value of these models in contributing to elimination of schistosomiasis. Treatment of schistosomiasis relies heavily on mass drug administration of praziquantel whose efficacy is comprised due to re-infections and experimental systems have revealed the inability to kill juvenile schistosomes. In terms of diagnosis, nonhuman primate models have demonstrated the low sensitivity of the gold standard Kato Katz smear technique. Antibody assays are valuable tools for evaluating efficacy of candidate vaccines, and sera from graded infection experiments are useful for evaluating diagnostic sensitivity of different targets. Lastly, the presence of Schistosomes can compromise the efficacy of vaccines to other infectious diseases and its elimination will benefit control programs of the other diseases. As the focus moves towards schistosomiasis elimination, it will be critical to integrate treatment, diagnostics, novel research tools such as sequencing, improved understanding of disease pathogenesis and utilization of experimental models to assist with evaluating performance of new approaches.

Systematic review to evaluate a potential association between helminth infection and physical stunting in children

Background

Despite considerable public health efforts over the past 20 years, childhood stunting (physical and/or cognitive) levels globally remain unacceptably high—at 22% amongst children under 5 years old in 2020. The aetiology of stunting is complex and still largely unknown. Helminths can cause significant mortality and morbidity and have often been cited as major causative agents for stunting, although their actual role in childhood stunting remains unclear. Our aim was to systematically review the current evidence to help support or refute the hypothesis that helminths cause physical stunting in children.

Methods

Inclusion criteria were as follows: infected with (and/or exposed to) helminths (soil-transmitted helminths, schistosomes or food-borne trematodes), children, pregnant or breastfeeding women as study participants (children included infants 0–1 year old, preschool-age children 1–5 years and school-age children > 5 years old), anthelmintic treatment intervention, stunting-related variables reported (e.g. height, height-for-age z-score, birth weight), helminth infection reported in relation to stunting, any geographic location, any date, peer-reviewed literature only. Exclusion criteria were: non-primary research, study protocols, studies with no new data, non-English language papers and animal (non-human) helminth studies. Seven databases were searched on 28 May 2021. Risk of bias was assessed for included studies and GRADE was used for studies included in RCT subgroup meta-analyses (in preschool-age children and pregnant women). This systematic review was registered with PROSPERO (CRD42021256201).

Results

Eighty studies were included in the analyses. No significant overall evidence was found in support of the hypothesis that helminths cause physical stunting in children, although there was some association with wasting.

Conclusions

Whilst analyses of the available literature to date failed to support a direct association between helminth infection and childhood stunting, there was significant heterogeneity between studies, and many had follow-up periods which may have been too short to detect impacts on growth. Most apparent was a lack of available data from key demographic groups wherein one may predict the greatest association of helminth infection with stunting—notably that of infants, preschool-age children, and pregnant or nursing women. Thus this review highlights the urgent need for further targeted empirical research amongst these potentially most vulnerable demographic groups.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05235-5.

The effect of schistosomiasis and soil-transmitted helminths on expressive language skills among African preschool children

Background

Schistosomiasis and soil transmitted helminths (STH) have been associated with compromised child development. We determined the effect of schistosomiasis and STH on expressive language skills among isiZulu speaking preschool children focusing on the variables: age, gender, school and stunting.

Methods

We quantitatively compared the performance of a cohort of infected and non-infected children using a 2 phased approach. In phase 1 infected children were treated with praziquantel and matched with non-infected children and both groups were tested for expressive language performance. In phase 2 both groups of children were re-tested for expressive language skills using a similar but modified test. The participants were 106 preschool children between the age of 4 and 6 years, 11 months. The Developmental Language Test was adapted as a linguistically and culturally appropriate tool for assessing isiZulu expressive language skills.

Results

The overall performance of the children in phases 1 and 2 were statistically similar. There was significant Pearson’s correlation of expressive language skills to age (0.002, P < 0.01), schistosomiasis i.e. vocabulary 1 (0.024, P < 0.05) and narrative skills (0.001, P < 0.01) and soil-transmitted helminths i.e. vocabulary 1 (0.006, P < 0.05), colours (0.029, P < 0.05) and narrative skills (0.001, P < 0.01) in phase 2 with small to high Cohen’s d effect size for various language subtests.

Conclusion

We concluded that even mild schistosomiasis and STH may compromise the performance of preschool children on expressive language. However poor ability in following instructions may have contributed to general poor performance across the two groups tested. Diet, school effect and stunting did not influence the performance of the children on expressive language.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07260-2.

Screening for parasites in migrant children

BACKGROUND

Globalization has pushed population movements in the last decades, turning imported diseases into the focus. Due to behavioral habits, children are at higher risk of acquiring iparasitosis. This study aims to investigate the prevalence of parasites in migrant children and factors associated with parasitic diseases.

METHOD

Retrospective cross-sectional study (2014-2018) including children diagnosed with parasitosis. The diagnosis was based on serology and/or microscopic stool-sample evaluation. Epidemiological and clinical data were recorded.

RESULTS

Out of 813 migrant children screened, 241 (29.6%) presented at least one parasite, and 89 (10.9%) more than one. The median age was 6.6 years (IQR: 3.1-11.9) and 58.9% were males. Most cases were referred for a health exam; only 52.3% of children were symptomatic, but 43.6% had eosinophilia. The most common diagnosis were giardiasis (35.3%), schistosomiasis (19.1%), toxocariasis (15.4%), and strongyloidiasis (9.1%). After the multivariate analysis, African origin and presenting with eosinophilia were the main risk factors for parasitism.

CONCLUSIONS

parasitosis are frequent among migrant children. Children are often asymptomatic, and thus active screening for parasitosis should be considered among high-risk populations. Eosinophilia can be useful to guide complimentary tests, as well as geographical origin, but normal eosinophil count does not exclude parasitosis.

Eosinophilia in Migrant Children: How Should We Proceed?

BACKGROUND

The diagnostic approach to eosinophilia is complex, given the numerous reported etiologies. Intestinal parasites (especially helminths) are a concern in children from high-burden settings. We describe the diagnostic approach and clinical management of eosinophilia in a cohort of migrant children.

METHODS

We conducted a retrospective observational study that included children diagnosed with eosinophilia at a reference center for pediatric tropical diseases from 2014 to 2018. All patients were screened according to a unified protocol, including direct microbiologic and serologic tests.

RESULTS

A total of 163 children presented with eosinophilia during the study period [median age, 7.7 years (4.1-12.2); 57.1% boys], mostly from Asia (27.6%) and South America (22.1%). Most were internationally adopted children (43.6%) or migrants (26.4%). Only 34.4% of the children were symptomatic, and the main etiology for eosinophilia was helminths (56.4%). After a sequential diagnostic approach, no etiology was found for 40.5% of the patients. The independent risk factors for an unexplained etiology were younger age (≤2 years: odds ratio, 3.6; 95% CI, 1.3-10.2; P = 0.015), absence of symptoms (odds ratio, 4.8; 95% CI, 1.8-12.5; P = 0.001) and mild eosinophilia (<1000/µL: odds ratio, 4.2; 95% CI, 4.5-11.7; P = 0.005). Only 6 children were treated empirically. In those children with an identified cause and in those treated empirically, the eosinophilia resolved in 52% in a median of 7 months (5-9).

CONCLUSIONS

Helminths are the main cause of eosinophilia in migrant children and need to be hunted, especially in older children with eosinophil counts >1000 eosinophils/µL.

Helminth-Induced Human Gastrointestinal Dysbiosis: a Systematic Review and Meta-Analysis Reveals Insights into Altered Taxon Diversity and Microbial Gradient Collapse

High-throughput 16S rRNA sequencing has allowed the characterization of helminth-uninfected (HU) and helminth-infected (HI) gut microbiomes, revealing distinct profiles. However, there have been no qualitative or quantitative syntheses of these studies, which show marked variation in participant age, diet, pathogen of interest, and study location. A predefined minimally biased search strategy identified 23 studies in humans. For each of these studies, we qualitatively addressed the effects of helminth infection on within-individual (alpha) and between-individual (beta) fecal microbiome diversity, infection-associated microbial taxa, the effect of helminth clearance on microbiome composition, microbiome composition as a predictor of infection status or treatment outcome, and treatment-specific effects on the fecal microbiome. Concomitantly, we performed a meta-analysis on a subset of 7 of these studies containing raw, paired-end 16S reads and individual-level metadata, comprising 424 pretreatment or untreated HI individuals and 497 HU controls. After reducing the batch effect and adjusting for age, our data demonstrated that intestinal helminth parasites can alter the host gut microbiome by increasing alpha diversity and promoting taxonomic reassortment and gradient collapse. Most strongly influencing the microbiome composition were the helminths found in the large intestine, Enterobius vermicularis and Trichuris trichiura, suggesting that this influence appears to be specific to soil-transmitted helminths (STH) species and host anatomical niche. In summary, using a large and diverse sample set captured in the meta-analysis, we were able to evaluate the influence of individual helminth species as well as species-species interactions, each of which explained a significant portion of the variation in the microbiome.

Status of Intestinal Helminth Infection in Schools Implementing the Home-Grown School Feeding Program and the Impact of the Program on Pupils in Anambra State, Nigeria

PURPOSE

Intestinal helminthiasis among pupils is a major impediment to their well-being and development. This 2-year study determined how home-grown school feeding programme (HGSFP) impacted on pupils' school attendance and created opportunity for more children to assess interventions geared towards the prevention and possible elimination of intestinal helminthiasis.

METHODS

Faecal samples were collected from 1677 consented pupils and examined for helminths using Kato-Katz technique. Pupils were treated with 40 mg Levamisole (anti-helminthic) and re-examined. Structured questionnaires and focus group discussions were used to determine anthropometric indices and risk factors.

RESULTS

A 6% prevalence rate which was not significant with respect to sex or age was observed. Helminth parasites observed were Ascaris lumbricoides (4.4%), Trichuris trichiura (0.8%), Hookworm spp. (0.2%), and Taenia spp. (0.5%). Two pupils (1.98%) recorded high intensity of infection (epg) while 98.02% had light infection. Ascaris lumbricoides voided following treatment were 290. The Body Mass Index (BMI) indicated that infected pupils had lower values (14.6317) compared to uninfected pupils (19.2003). The HGSFP significantly improved school attendance by 30%. Lack of knowledge about transmission (P = 0.0004), hand hygiene (P = 0.01) and usage of toilet (P = 0.01) were risk factors observed.

CONCLUSION/SIGNIFICANCE

Intestinal helminthiasis remains a public health problem among pupils because environmental and behavioural risk factors persist. HGSFP improved school attendance and created opportunity for more inclusive participation of school-aged children for deworming. This has great potential in fast-tracking the elimination of intestinal helminthiasis. The present study consequently advocates the need to sustain HGSFP in schools.

A historical and systematic overview of Ascaris vaccine development

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

Un-‘Egg’-Plored: Characterisation of Embryonation in the Whipworm Model Organism Trichuris muris

Trichuris muris, is the murine parasite and widely deployed model for the human whipworm Trichuris trichiura, a parasite that infects around 500 million people globally. Trichuriasis is a classical disease of poverty with a cycle of re-infection due to the continual exposure of humans, particularly children, to infective eggs, which contaminate the soil in endemic areas. Indeed, modelling studies of trichuriasis have demonstrated that the low efficacy rate of current anthelmintics combined with the high possibility of re-infection from the reservoir of infective eggs within the environment, mean that the elimination of morbidity due to trichuriasis is unlikely to occur. Despite the importance of the infective egg stage in the perpetuation of infections, understanding the biology of the Trichuris ova has been neglected for decades. Here we perform experiments to assess the impact of temperature on the embryonation process of T. muris eggs and describe in detail the stages of larval development within these eggs. In keeping with the early works performed in the early 1900s, we show that the embryonation of T. muris is accelerated by an elevation in temperature, up to 37°C above which eggs do not fully develop and become degenerate. We extend these data to provide a detailed description of T. muris egg development with clear images depicting the various stages of development. To the best of our knowledge we have, for the first time, described the presence of birefringent granules within egg-stage larvae, as well as providing a qualitative and quantitative description of a motile larval stage prior to quiescence within the egg. These experiments are the first step towards a better understanding of the basic biology which underlies the process of egg embryonation. With the threat of elevation in global temperatures, the accelerated embryonation rate we observe at higher temperatures may have important consequences for parasite transmission rates and prospective modelling studies. In addition, a deeper understanding of the Trichuris ova may allow the development of novel control strategies targeting the egg stage of Trichuris in the environment as an adjunct to MDA.

The Influence of Helminth Immune Regulation on COVID-19 Clinical Outcomes: Is it Beneficial or Detrimental?

Immunologically, chronic worm infections prevent themselves from strong immune responses by skewing the host response towards a T helper 2 (Th2) type. The regulatory response initiated by helminth infections is supposed to temper responses to non-helminth antigens including viral infections which will, in turn, alter the clinical outcomes of infections. In view of this, recent reports highlighted the possible negative associations of severe COVID-19 and helminth co-infections in helminth-endemic regions. As the pathology of COVID-19 is primarily mediated by an excessive immune response and subsequent cytokine storm, which contributes to the poor prognosis of COVID-19, helminth-driven immune modulation will hypothetically contribute to the less severe outcomes of COVID-19. Nevertheless, emerging reports also stated that COVID-19 and helminth co-infections may have more hidden outcomes than predictable ones. Herein, the current knowledge on the interaction of COVID-19 and helminth co-infections will be discussed.

The prevalence of soil transmitted helminth infections in minority indigenous populations of South-East Asia and the Western Pacific Region: A systematic review and meta-analysis

INTRODUCTION

Soil transmitted helminth (STH) infections cause one of the most prevalent diseases in man. STHs disproportionately impact socio-economically disadvantaged communities including minority indigenous populations. This systematic review aimed to quantify the prevalence of STH infection within minority indigenous populations of the South-East Asia and Western Pacific Regions.

METHODS

The systematic review was conducted in accordance with The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines following a published protocol. A random effects meta-analysis was used to estimate the pooled prevalence of STH infection, and meta-regression analysis was used to quantify associations with study characteristics. Where comparative data were available, sub-group analysis was conducted to evaluate the risk of STH infection in minority indigenous people relative to other population groups. The heterogeneity between studies was evaluated visually using Forest plots and was assessed quantitatively by the index of heterogeneity (I2) and Cochran Q-statistics.

RESULTS

From 1,366 unique studies that were identified, 81 were included in the final analysis. The pooled prevalence of infection within minority indigenous populations was 61.4% (95% CI 50.8, 71.4) for overall STH infection; 32.3% (95% CI 25.7, 39.3) for Ascaris.lumbricoides; 43.6% (95% CI 32.6, 54.8) for Trichuris.trichiura; 19.9% (95% CI 15.7, 24.5) for hookworm and 6.3% (95% CI 3.2, 10.2) for Strongyloides.stercoralis. A significant increase in T. trichiura prevalence was observed over time. The stratified analysis showed that the prevalence of infection for STH overall and for each STH species were not significantly different in minority indigenous participants compared to other populations groups.

CONCLUSION

The prevalence of STH infection is high within minority indigenous populations across countries at very different levels of socio-economic development. The increasing prevalence of T. trichiura calls for the implementation of more effective therapies and control strategies.

Helminth extracellular vesicles: Interactions with the host immune system

As long-lived parasites, helminths depend upon immunomodulation of their hosts for survival. The release of excretory-secretory (ES) products, including proteins, lipids and RNAs is how successful host manipulation is achieved. It has recently been discovered that the ES products of helminths contain extracellular vesicles (EVs), with every species investigated found to secrete these lipid-bound structures. EVs are perfect for packaging and delivering immune modulators to target cell types. This review outlines the research carried out on helminth EVs and their constituents thus far, as well as their interaction with components of the mammalian immune system. We discuss how targeting EVs will aid treatment of helminth infection and consider how EVs and their immunomodulatory cargo could be used as therapeutics as we progress through this exciting era.

Neurocognitive outcomes in Malawian children exposed to malaria during pregnancy: An observational birth cohort study

BACKGROUND

Annually 125 million pregnancies are at risk of malaria infection. However, the impact of exposure to malaria in pregnancy on neurodevelopment in children is not well understood. We hypothesized that malaria in pregnancy and associated maternal immune activation result in neurodevelopmental delay in exposed offspring.

METHODS AND FINDINGS

Between April 2014 and April 2015, we followed 421 Malawian mother-baby dyads (median [IQR] maternal age: 21 [19, 28] years) who were previously enrolled (median [IQR] gestational age at enrollment: 19.7 [17.9, 22.1] weeks) in a randomized controlled malaria prevention trial with 5 or 6 scheduled assessments of antenatal malaria infection by PCR. Children were evaluated at 12, 18, and/or 24 months of age with cognitive tests previously validated in Malawi: the Malawi Developmental Assessment Tool (MDAT) and the MacArthur-Bates Communicative Development Inventories (MCAB-CDI). We assessed the impact of antenatal malaria (n [%] positive: 240 [57.3]), placental malaria (n [%] positive: 112 [29.6]), and maternal immune activation on neurocognitive development in children. Linear mixed-effects analysis showed that children exposed to antenatal malaria between 33 and 37 weeks gestation had delayed language development across the 2-year follow-up, as measured by MCAB-CDI (adjusted beta estimate [95% CI], -7.53 [-13.04, -2.02], p = 0.008). Maternal immune activation, characterized by increased maternal sTNFRII concentration, between 33 and 37 weeks was associated with lower MCAB-CDI language score (adjusted beta estimate [95% CI], -8.57 [-13.09, -4.06], p < 0.001). Main limitations of this study include a relatively short length of follow-up and a potential for residual confounding that is characteristic of observational studies.

CONCLUSIONS

This mother-baby cohort presents evidence of a relationship between malaria in pregnancy and neurodevelopmental delay in offspring. Malaria in pregnancy may be a modifiable risk factor for neurodevelopmental injury independent of birth weight or prematurity. Successful interventions to prevent malaria during pregnancy may reduce the risk of neurocognitive delay in children.

Diagnostic Techniques for Soil-Transmitted Helminths - Recent Advances

Soil-transmitted helminth (STH) infections (hookworms, Trichuris, Ascaris) and Strongyloides spp. are associated with a substantial global burden and high morbidity. Sensitive and specific methods for diagnosis of these infections are essential for mapping the burden in communities, accurate assessment of infection levels, to guide interventions and monitoring the success of STH control programs. Despite considerable progress to control STH over several decades, we are still far from identifying a fully adequate diagnostic test. Conventional microscopy-based methods such as direct Kato–Katz smear or mounts after stool centrifugation/flotation-based concentration techniques have been the mainstay of diagnosis, especially in resource-poor countries where these infections abound. However, recently, these are being adapted to closed, easy to perform, digital formats, thereby improving the sensitivity as well as applicability in a remote, resource-limited setting. The use of image analysis systems to identify and quantify helminth eggs, with potential adaptation to smartphones, is also promising. Antibody detection tests have a limited role mostly in the case of Strongyloides hyperinfection. Coproantigen detection tests have been developed and used in veterinary practice for detection of STH, but these have not been evaluated for use in humans. More sensitive molecular diagnostics, including assays developed with new bioinformatic tools and techniques such as polymerase chain reaction (PCR), quantitative PCR (qPCR) and loop-mediated amplification assay, can help in the clear and precise assessment of STH burden during elimination phase and are of immense value for diagnosis in areas with low endemicity and in travelers to endemic regions. Moreover, the molecular techniques will help detect new species that may emerge. Sample preservation and efficient DNA extraction are critical and significantly affect the efficiency of molecular diagnostic tests. In addition to the diagnosis of clinical or asymptomatic infection in humans, detection of STH eggs in environmental samples is imperative to boost STH control efforts. Overall the diagnostic performance, cost-effectiveness, ease of performance, rapidity and in-field applicability of any test should be considered when choosing from the various diagnostic assays in areas with different endemicity, in addition to striving towards the development of novel technologies and optimization of existing methods.

Assessing early child development and its association with stunting and schistosome infections in rural Zimbabwean children using the Griffiths Scales of Child Development

There is a paucity of reference early childhood development (ECD) data at community level in rural Africa. Our objective was to conduct a comprehensive assessment of ECD in rural Zimbabwe and determine the impact of stunting and schistosome infections on ECD. Using the Griffiths Scales of Child Development, we conducted a cross sectional assessment of Eye and Hand Coordination (EHC), Personal-Social-Emotional (PSE), Language and Communication (LC), Foundations of Learning (FL) and Gross Motor (GM) domains and the summary General Development (GD) in 166 children aged 6-72 months. The effects of stunting, malnutrition and Schistosoma haematobium infection on ECD was determined. The impact of praziquantel curative treatment of schistosome infection on the developmental scores was determined through a longitudinal follow up at 6 and 12 months. From an initial 166 children, 11 were found to have developmental deficits warranting further investigation. Of the remaining 155, 58.7% recorded a good (≥ average) score for the overall General Development (GD). Proportions of children scoring above the cut-off (≥ average) for each domain were GM (84.5%), PSE (80.6%), EHC (61.9%), FL (43.9%) and LC (44.5%). The prevalence of stunting was 26.8% (95% CI = 20.1%-34.8%) Scores for stunted children were significantly lower for EHC (p = 0.0042), GM (p = 0.0099), and GD (p = 0.0014) with the fraction of lower scores attributable to stunting being GM = 63.4%, GD = 46.6%, EHC = 45%, and LC = 21%. S. haematobium infection prevalence was 39.7% and mean infection intensity was 5.4 eggs/10 ml urine. Infected children had poorer cognitive performance scores for the FL (p = 0.0005) with 30.8% of poor FL attributable to the infection. Performance in all domains improved to the expected normal or above reference levels at 6 and 12 months post curative treatment of schistosome infections. Our study documented reference values for ECD in rural Zimbabwean children. The study detected deficiencies in the FL domain, which were more pronounced in children, infected with schistosomes, highlighting the need for provision of cognitive stimulation tools and access to early childhood foundation education. There is also need for improved child nutrition and treatment of schistosome infections to improve child development outcomes.

Field evaluation of the gut microbiome composition of pre-school and school-aged children in Tha Song Yang, Thailand, following oral MDA for STH infections

Soil-transmitted helminths, such as roundworms (Ascaris lumbricoides), whipworms (Trichuris trichiura) and hookworms (Necator americanus and Ancylostoma spp.), are gastrointestinal parasites that occur predominantly in low- to middle-income countries worldwide and disproportionally impact children. Depending on the STH species, health status of the host and infection intensity, direct impacts of these parasites include malnutrition, anaemia, diarrhoea and physical and cognitive stunting. The indirect consequences of these infections are less well understood. Specifically, gastrointestinal infections may exert acute or chronic impacts on the natural gut microfauna, leading to increased risk of post-infectious gastrointestinal disorders, and reduced gut and overall health through immunomodulating mechanisms. To date a small number of preliminary studies have assessed the impact of helminths on the gut microbiome, but these studies are conflicting. Here, we assessed STH burden in 273 pre-school and school-aged children in Tha Song Yang district, Tak province, Thailand receiving annual oral mebendazole treatment. Ascaris lumbricoides (107/273) and Trichuris trichiura (100/273) were the most prevalent species and often occurred as co-infections (66/273). Ancylostoma ceylanicum was detected in a small number of children as well (n = 3). All of these infections were of low intensity (<4,999 or 999 eggs per gram for Ascaris and Trichuris respectively). Using this information, we characterised the baseline gut microbiome profile and investigated acute STH-induced alterations, comparing infected with uninfected children at the time of sampling. We found no difference between these groups in bacterial alpha-diversity, but did observe differences in beta-diversity and specific differentially abundant OTUs, including increased Akkermansia muciniphila and Bacteroides coprophilus, and reduced Bifidobacterium adolescentis, each of which have been previously implicated in STH-associated changes in the gut microfauna.

Soil-transmitted helminth infections exhibit a significant negative impact on population health worldwide. In particular in endemic regions sub-groups such as children suffer disproportionally from infection due to impoverished living conditions. Yet many of these regions have no or limited availability of infection prevalence data to inform intervention strategies. Application of low sensitivity diagnostic tools such as microscopy exacerbate this issue. Moving towards molecular tools is key in order to establish a more accurate and complete epidemiological profile that can serve as a reference standard for future studies. Recently, a number of studies investigated the microbiota as an important factor determining overall patient health. The gut microbiota can be altered through medication, lifestyle factors and co-inhabitation of the same environmental niche with STHs. However, these microbiota studies often lack a characterised baseline. The current study provides baseline epidemiology data for a cohort of pre-school and school-age Thai children using a molecular diagnostic technique. We estimate the STH infection prevalence and intensity and characterise the host gut microbiota profile at a single cross-sectional timepoint comparing infected with uninfected children. This data can serve as a starting point for future studies investigating the impact of environmental factors and parasitic infections on patient health.

Evaluating Equity and Coverage in Mass Drug Administration for Soil-Transmitted Helminth Infections among School-Age Children in the Hard-to-Reach Setting of Southern Ethiopia

BACKGROUND

Soil-transmitted helminth (STH) infections are prevalent in most developing countries, including Ethiopia, with school-age children (SAC) at high risk of infection. In Ethiopia, despite substantial progress being made on mass drug administration (MDA) coverage for STH infections, its implementation is facing challenges in hard-to-reach areas. This study thus aimed at assessing equity and coverage in MDA and identifying factors associated with drug coverage for STH infections among SAC in the hard-to-reach setting of southern Ethiopia.

METHODS

A community-based cross-sectional survey was conducted in the North Ari district, South Omo Zone in July 2019. Sample size was estimated following WHO drug-coverage evaluation guidelines. Factors associated with drug uptake for STH infections were identified using multivariate logistic regression.

RESULTS

Of 956 SAC participating in this study, the overall MDA coverage for STH was found to be 27.5% (95% CI 24.7%-30.5%). The odds of having taken drugs were highest among school-enrolled children and in those who knew the purpose of MDA: about about double their counterparts. In contrast, the odds of drug uptake were lower by 69% among those who had got informed only when the drugs delivered and by 92% among those who needed to travel >30 minutes to reach drug-distribution points than their counterparts.

CONCLUSION

Achieving effective and equitable MDA coverage is facing serious challenges in the hard-to-reach setting of southern Ethiopia. The very low (27.5%) and inequitable MDA coverage found in this study are associated with school nonenrollment, inaccessibility, and lack of information, awareness, and mobilization. Social mobilization should be scaled up to inform and create awareness in the community ahead of MDA. Further, school-based deworming in settings with low school enrollment needs a modified strategy to reach those in need of drugs.

Prevalence of Stunting and Relationship between Stunting and Associated Risk Factors with Academic Achievement and Cognitive Function: A Cross-Sectional Study with South African Primary School Children

Childhood stunting can have negative long-term consequences on cognitive development, academic achievement, and economic productivity later in life. We determined the prevalence of stunting and examined whether stunting and associated risk factors (low dietary diversity, insufficient hemoglobin, food insecurity, and soil-transmitted helminth (STH) infections) are associated with academic achievement and cognitive function among South African children living in marginalized communities. A cross-sectional sample of 1277 children (aged 5–12 years) was analyzed. Stunting was defined according to 2007 WHO growth references. Cognitive functioning was measured with the computerized Flanker task and academic performance via school grades. Blood and stool samples were collected to obtain hemoglobin level and STH infection. Dietary diversity was assessed by a food frequency questionnaire. Associations were examined via mixed linear regression (with school class as a random intercept). Nine percent of the children were stunted (95% CI: 7.6–10.8%). Low dietary diversity (β = 0.13, p = 0.004), food insecurity (β = −0.12, p = 0.034), and stunting (β = −0.13, p = 0.031) were associated with poorer end of the year results among girls. No such associations were found among boys. No significant associations were found for socioeconomic status and hemoglobin levels. The prevalence of stunting and STH infections were low in the present sample. Risk factors seem differently associated with girls’ and boys’ academic achievement. Promoting nutrition may help to promote academic achievement among girls living in low- and middle-income countries.

Peripheral Taenia infection increases immunoglobulins in the central nervous system

Human cysticercosis is a disease caused by larvae of the cestode Taenia solium. It is an important common cause of adult-onset seizures world-wide where it exacts a debilitating toll on the health and well-being of affected communities. It is commonly assumed that the major symptoms associated with cysticercosis are a result of the direct presence of larvae in the brain. As a result, the possible effects of peripherally located larvae on the central nervous system are not well understood. To address this question, we utilised the Taenia crassiceps intra-peritoneal murine model of cysticercosis, where larvae are restricted to the peritoneal cavity. In this model, previous research has observed behavioural changes in rodents but not the development of seizures. Here we used ELISAs, immunoblotting and the Evans Blue test for blood-brain barrier permeability to explore the central effects of peripheral infection of mice with T. crassiceps. We identified high levels of parasite-targeting immunoglobulins in the sera of T. crassiceps-infected mice. We show that the T. crassciceps larvae themselves also contain and release host immunoglobulins over time. Additionally, we describe, for the first known time, significantly increased levels of IgG within the hippocampi of infected mice, which are accompanied by changes in blood-brain barrier permeability. However, these T. crassiceps-induced changes were not accompanied by alterations to the levels of proinflammatory, pro-seizure cytokines in the hippocampus. These findings contribute to the understanding of systemic and neuroimmune responses in the T. crassiceps model of cysticercosis, with implications for the pathogenesis of human cysticercosis.

Effectiveness of Deworming with Single-Dose Albendazole for Preschool-Aged Children in the Dominican Republic

Background. The World Health Organization recommends biannual deworming with single-dose albendazole for all children over 1 year in regions where soil-transmitted helminths (STH) are endemic. There are limited data from the Dominican Republic (DR) on the effectiveness of deworming programs. Methods. Between January and June 2019, we enrolled 63 preschool-aged children at a community clinic in the DR. Participants received albendazole at enrollment. Stool samples were collected and examined for parasites at enrollment, 2 to 4 and 12 to 16 weeks post-albendazole. Caregivers were surveyed on home hygiene practices and children’s symptoms. Findings. At enrollment, 1 or more parasites were noted in 89% of samples. Ascaris lumbricoides (68%) was the most common species, followed by Entamoeba histolytica (35%) and Giardia intestinalis (8%). Two-to-four weeks post-albendazole, fewer than half of those with A. lumbricoides infections at baseline had cleared the infection. STH symptoms significantly improved between enrollment and 2 to 4 weeks. By 12 to 16 weeks after treatment, A. lumbricoides infections were as high as baseline. Interpretation. Although limited by size and available technology, our study contributes data on STH in the DR. Single-dose deworming with albendazole did not reduce Ascaris lumbricoides infections in our sample. As STH are the most common neglected tropical diseases and negatively impact children’s health globally, further studies on both effective deworming programs and interventions to prevent STH are needed.

Soil-transmitted helminth infection in pregnancy and long-term child neurocognitive and behavioral development: A prospective mother-child cohort in Benin

Background

An estimated 30% of women in Sub-Saharan Africa suffer from soil-transmitted helminth infection during pregnancy (SHIP), which has been shown to increase risk of pre-term birth, low birth weight, and maternal anemia. A previous study in Benin found that SHIP was associated with impaired cognitive and gross motor development scores in 635 one-year-old children. The objective of the present study was to follow children prospectively to investigate whether the association between SHIP and child neurocognitive and behavioral development persisted at age six.

Principal findings

Our prospective child cohort included 487 live-born singletons of pregnant women enrolled in the Malaria in Pregnancy Preventive Alternative Drugs clinical trial in Allada, Benin. SHIP was assessed at three antenatal visits (ANVs) through collection and testing of stool samples. Neurocognitive and behavioral development was assessed in six-year-old children by trained investigators using the Kaufman Assessment Battery for Children 2^nd edition and the parent-reported Strengths and Difficulties Questionnaire (SDQ). Multiple linear regression models generated coefficients and 95% confidence intervals and potential mediating factors were tested. Prevalence of SHIP was 13% at the 1^st ANV, 9% at the 2^nd ANV, and 1% at delivery. SHIP was not associated with low neurocognitive scores in children at six years. Higher SDQ internalizing scores, indicating increased emotional impairments in children, were associated with helminth infection at the 2^nd ANV/delivery 1.07 (95% CI 0.15, 2.00) and at least once during pregnancy 0.79 (95% CI 0.12, 1.46) in adjusted models. Mediation analysis did not reveal significant indirect effects of several mediators on this association.

Conclusions

Our study shows that while SHIP is not associated with impaired long-term neurocognitive development, infections may have significant negative impacts on emotional development in six-year-old children. SHIP remains a critical public health issue, and adequate prevention and treatment protocols should be enforced in low- and middle-income countries.

Soil-transmitted helminth infections impact 1.5 billion individuals, primarily in low- and middle- income countries, each year and contribute to malnutrition, anemia, and impaired neurocognitive development in children. However, these infections in pregnancy and their impact on offspring have been less studied. One previous study found associations between soil-transmitted helminth infection during pregnancy and impaired cognitive functioning in offspring one year after birth. The current study aimed to follow these children prospectively until six years in order to confirm whether these associations persisted or not. Infections during pregnancy were no longer associated with cognitive or motor functioning in children; however, infections were associated with impaired behavioral development. Animal-based models have hypothesized maternal inflammation and poor birth outcomes to be the mechanisms behind this relationship; however, our findings did not support these mechanisms. This is one of very few prospective cohort studies in Sub-Saharan Africa to investigate these associations, and more research is needed to corroborate results. Limitations include limited power and the possibility that results are due to chance from multiple statistical tests. Adequate and accessible prevention and treatment efforts in pregnancy and childhood should be provided to populations in low- and middle- income countries at high risk of infection.

Malaria and helminth co-infections in children living in endemic countries: A systematic review with meta-analysis

Background

Current knowledge on the burden of, and interactions between malaria and helminth co-infections, as well as the impact of the dual infections on anaemia, remains inconclusive. We have conducted a systematic review with meta-analysis to update current knowledge as a first step towards developing and deploying coordinated approaches to the control and, ultimately, elimination of malaria-helminth co-infections among children living in endemic countries.

Methodology/Principal findings

We searched Medline, Embase, Global Health and Web of Science from each database inception until 16 March 2020, for peer-reviewed articles reporting malaria-helminth co-infections in children living in endemic countries. No language restriction was applied. Following removal of duplicates, two reviewers independently screened the studies for eligibility. We used the summary odds ratio (OR) and 95% confidence intervals (CI) as a measure of association (random-effects model). We also performed Chi-square heterogeneity test based on Cochrane’s Q and evaluated the severity of heterogeneity using I² statistics. The included studies were examined for publication bias using a funnel plot and statistical significance was assessed using Egger’s test (bias if p<0.1).

Fifty-five of the 3,507 citations screened were eligible, 28 of which had sufficient data for meta-analysis. The 28 studies enrolled 22, 114 children in 13 countries across sub-Saharan Africa, Southeast Asia and South America. Overall, the pooled estimates showed a prevalence of Plasmodium-helminth co-infections of 17.7% (95% CI 12.7–23.2%). Summary estimates from 14 studies showed a lower odds of P. falciparum infection in children co-infected with Schistosoma spp (OR: 0.65; 95%CI: 0.37–1.16). Similar lower odds of P. falciparum infection were observed from the summary estimates of 24 studies in children co-infected with soil transmitted helminths (STH) (OR: 0.42; 95%CI: 0.28–0.64).

When adjusted for age, gender, socio-economic status, nutritional status and geographic location of the children, the risk of P. falciparum infection in children co-infected with STH was higher compared with children who did not have STH infection (OR = 1.3; 95% CI 1.03–1.65).

A subset of 16 studies showed that the odds of anaemia were higher in children co-infected with Plasmodium and STH than in children with Plasmodium infection alone (OR = 1.20; 95% CI: 0.59–2.45), and were almost equal in children co-infected with Plasmodium-Schistosoma spp or Plasmodium infection alone (OR = 0.97, 95% CI: 0.30–3.14).

Conclusions/Significance

The current review suggests that prevalence of malaria-helminth co-infection is high in children living in endemic countries. The nature of the interactions between malaria and helminth infection and the impact of the co-infection on anaemia remain inconclusive and may be modulated by the immune responses of the affected children.

Updated evidence is needed to guide the planning and implementation of appropriate interventions for control of mixed infections involving malaria and worms affecting children living in endemic countries. We performed a systematic review and meta-analysis to update current knowledge on the magnitude of the burden of dual infections with malaria and worms in children in the developing world. We searched all published articles available in Medline, Embase, Global Health and Web of Science from the database inception until 16 March 2020, without any language restriction. We found 55 eligible studies, and 28 of these studies were included in the meta-analysis. A summary of the evidence synthesis showed that the burden of dual infections involving malaria and worm parasites is high in children and varies significantly across endemic countries. There was a lower risk of P. falciparum infection in children infected with soil transmitted helminths (STH) or S. haematobium or S.mansoni. Conversely, the odds of anaemia were higher in children who had dual infections with Plasmodium and STH parasites than in children with a Plasmodium infection alone while the odds of anaemia were almost equal in children who were co-infected with Plasmodium-Schistosoma compared to those with a Plasmodium infection alone. These findings underscore the need to further understand the epidemiology of malaria-helminth co-infections in order to support implementation of appropriate interventions for control and, ultimately, elimination of the dual infections in children living in endemic countries, especially low and middle-income countries (LMIC).

Prevalence, Infection Intensity and Associated Factors of Soil-Transmitted Helminthiasis Among School-Aged Children from Selected Districts in Northwest Ethiopia

Background

Globally, soil-transmitted helminths affect beyond a billion people and cause 1.9 million disability-adjusted life years worldwide. It affects children disproportionately due to their unaware activities like walking barefoot, playing with dirty objects that might be contaminated with feces. The control of soil-transmitted helminths principally relies on periodic deworming using either a single dose of albendazole/mebendazole. To assure the effectiveness of this measure, performing continuous parasitological survey is necessary. Herein, the prevalence, intensity and associated factors of soil-transmitted helminth infections were assessed among school-aged children in northwest Ethiopia.

Methods

A cross-sectional study design was conducted among school-aged children (6–14 years old) from January 21st to February 21st/2019. Multistage sampling technique was employed. A Kato-Katz concentration technique was utilized to detect STHs in stool samples. Moreover, risk factors for STH infections were assessed using well-structured questionnaire. Bivariate and multivariate analyses were used to assess the association between explanatory and the outcome variables. The magnitude of the association was measured using the adjusted odds ratio (AOR) and 95% confidence interval (CI). A P-value <0.05 was considered statistically significant.

Results

The overall STHs prevalence in this study was 32.3% (95% CI: 29–35.6%) with Ascaris lumbricoides being the predominant species (24.3%) followed by hookworm (8.9%) and Trichuris trichiura (1%). Most (80.3%) of the infected school-aged children had light-intensity infections. Age of 11 years and above (AOR, 12.9, 95% CI, 1.6–103.6, P=0.004), being residing in Chuahit district (AOR, 3.9, 95% CI, 2.3–6.5, P<0.001), and untreated water supply (AOR, 1.7, 95% CI, 1.1–2.7, P=0.018) were identified as predictors for the overall STH prevalence.

Conclusion

Our findings revealed STH infections are considerable health problems in the study areas. Thus, public health interventions such as provision of safe water supply, health education, and de-worming programs should be regularly implemented in the study areas.