Impact of Health Education on Soil-Transmitted Helminth Infections in Schoolchildren of the Peruvian Amazon: A Cluster-Randomized Controlled Trial

Background: To control soil-transmitted helminth (STH) infections, the World Health Organization recommends school-based deworming programs with a health hygiene education component. The effect of such health hygiene interventions, however, has not been adequately studied. The objective of the present study was to determine the effectiveness of a health hygiene education intervention on the occurrence of STH re-infection four months post-de-worming. Methodology/Principal Findings An open-label pair-matched cluster-randomized trial was conducted in Grade 5 schoolchildren of 18 primary schools (9 intervention and 9 control) in the Peruvian Amazon. Baseline assessment included interview with a pre-tested questionnaire and collection of single stool specimens that were examined using the single Kato-Katz thick smear. All schoolchildren were then treated with single-dose albendazole (400 mg). Schoolchildren in intervention schools then received 1) an initial one hour in-class activity on health hygiene and sanitation and 30-minute refresher activities every two weeks over four months; and 2) a half-day workshop for teachers and principals, while children in control schools did not. Four months later, STH infection was re-assessed in all schools by laboratory technologists blinded to intervention status. From April 21–October 20, 2010, a total of 1,089 schoolchildren (518 and 571 from intervention and control schools, respectively) participated in this study. Intervention children scored significantly higher on all aspects of a test of STH-related knowledge compared with control children (aOR = 18·4; 95% CI: 12·7 to 26·6). The intensity of Ascaris lumbricoides infection at follow-up was statistically significantly lower (by 58%) in children in intervention schools compared with children in control schools (aIRR = 0·42; 95% CI = 0·21 to 0·85). No significant changes in hookworm or Trichuris trichiura intensity were observed. Conclusions/Significance: A school-based health hygiene education intervention was effective in increasing STH knowledge and in reducing Ascaris lumbricoides infection. The benefits of school-based periodic deworming programs are likely to be enhanced when a sustained health hygiene education intervention is integrated into school curricula

Effects of a Post-Deworming Health Hygiene Education Intervention on Absenteeism in School-Age Children of the Peruvian Amazon

Soil-transmitted helminth (STH) infections are a leading cause of disability and disease burden in school-age children of worm-endemic regions. Their effect on school absenteeism, however, remains unclear. The World Health Organization currently recommends delivering mass deworming and health hygiene education through school-based programs, in an effort to control STH-related morbidity. In this cluster-RCT, the impact of a health hygiene education intervention on absenteeism was measured. From April to June 2010, all Grade 5 students at 18 schools in a worm-endemic region of the Peruvian Amazon were dewormed. Immediately following deworming, nine schools were randomly assigned to the intervention arm of the trial using a matched-pair design. The Grade 5 students attending intervention schools (N = 517) received four months of health hygiene education aimed at increasing knowledge of STH prevention. Grade 5 students from the other nine schools (N = 571) served as controls. Absenteeism was measured daily through teachers' attendance logs. After four months of follow-up, overall absenteeism rates at intervention and control schools were not statistically significantly different. However, post-trial non-randomized analyses have shown that students with moderate-to-heavy Ascaris infections and light hookworm infections four months after deworming had, respectively, missed 2.4% (95% CI: 0.1%, 4.7%) and 4.6% (95% CI: 1.9%, 7.4%) more schooldays during the follow-up period than their uninfected counterparts. These results provide empirical evidence of a direct effect of STH infections on absenteeism in school-age children

Risk Factors Associated with Malnutrition in One-Year-Old Children Living in the Peruvian Amazon

Background: Children under two years of age are in the most critical window for growth and development. As mobility increases, this time period also coincides with first exposure to soil-transmitted helminth (STH) infections in tropical and sub-tropical environments. The association between malnutrition and STH infection, however, has been understudied in this vulnerable age group. Methodology/Principal Findings A nested cross-sectional survey was conducted in 12 and 13-month old children participating in a deworming trial in Iquitos, an STH-endemic area of the Peruvian Amazon. An extensive socio-demo-epi questionnaire was administered to the child's parent. Length and weight were measured, and the Bayley Scales of Infant and Toddler Development were administered to measure cognition, language, and fine motor development. Stool specimens were collected to determine the presence of STH. The association between malnutrition (i.e. stunting and underweight) and STH infection, and other child, maternal, and household characteristics, was analyzed using multivariable Poisson regression. A total of 1760 children were recruited between September 2011 and June 2012. Baseline data showed a prevalence of stunting and underweight of 24.2% and 8.6%, respectively. In a subgroup of 880 randomly-allocated children whose specimens were analyzed by the Kato-Katz method, the prevalence of any STH infection was 14.5%. Risk factors for stunting in these 880 children included infection with at least one STH species (aRR = 1.37; 95% CI 1.01, 1.86) and a lower development score (aRR = 0.97; 95% CI: 0.95, 0.99). A lower development score was also a significant risk factor for underweight (aRR = 0.92; 95% CI: 0.89, 0.95). Conclusions: The high prevalence of malnutrition, particularly stunting, and its association with STH infection and lower developmental attainment in early preschool-age children is of concern. Emphasis should be placed on determining the most cost-effective, integrated interventions to reduce disease and malnutrition burdens in this vulnerable age group

A double-blind randomized controlled trial of maternal postpartum deworming to improve infant weight gain in the Peruvian Amazon

Background : Nutritional interventions targeting the critical growth and development period before two years of age can have the greatest impact on health trajectories over the life course. Compelling evidence has demonstrated that interventions investing in maternal health in the first 1000 days of life are beneficial for both mothers and their children. One such potential intervention is deworming integrated into maternal postpartum care in areas where soil-transmitted helminth (STH) infections are endemic. Methodology/Principal Findings : From February to August 2014, 1010 mother-infant pairs were recruited into a trial aimed at assessing the effectiveness of maternal postpartum deworming on infant and maternal health outcomes. Following delivery, mothers were randomly assigned to receive either single-dose 400 mg albendazole or placebo. Participants were followed-up at 1 and 6 months postpartum. There was no statistically significant difference in mean weight gain between infants in the experimental and control groups (mean difference: -0.02; 95% CI: -0.1, 0.08) at 6 months of age. Further, deworming had no effect on measured infant morbidity indicators. However, ad hoc analyses restricted to mothers who tested positive for STHs at baseline suggest that infants of mothers in the experimental group had greater mean length gain in cm (mean difference: 0.8; 95% CI: 0.1, 1.4) and length-for-age z-score (mean difference: 0.5; 95% CI: 0.2, 0.8) at 6 months of age. Conclusions/Significance : In a study population composed of both STH-infected and uninfected mothers, maternal postpartum deworming was insufficient to impact infant growth and morbidity indicators up to 6 months postpartum. Among STH-infected mothers, however, important improvements in infant length gain and length-for-age were observed. The benefits of maternal postpartum deworming should be further investigated in study populations having higher overall prevalences and intensities of STH infections and, in particular, where whipworm and hookworm infections are of public health concern

The effect of timing of umbilical cord clamping on newborn anemia: implications for clinical practice in the Peruvian Amazon

Delayed umbilical cord clamping has been shown to decrease the risk of infant anemia. A pre-post study design was used to determine the effectiveness of a two-component intervention (workshop and directive) in delaying cord clamping. Women were recruited from the labour room of Hospital Iquitos in Iquitos Peru pre (N=112) and post intervention (N=112). Maternal hemoglobin was assessed before delivery; time-to-cord clamping was recorded at delivery and infant hemoglobin was measured at four months of age. Time-to-clamp increased significantly by 113 seconds following the intervention (βadjusted = 113.2 seconds, 95% CI: 96.6, 129.9). Maternal anemia was identified as an effect modifier on the relationship between time-to-clamp and infant anemia. In infants born to anemic women, the odds ratio of developing anemia is 0.59 for every one minute delay in cord clamping. These findings add to the mounting support for delayed cord clamping as a means to decrease infant anemia.Des études ont démontré que retarder la coupure du cordon ombilical pourrait réduire les risques d'anémie infantile. Un plan d'étude pré/post a été utilisé pour déterminer l'efficacité d'une intervention visant à retarder la coupure du cordon. Des femmes ont été recrutées à l'Hôpital Iquitos (Pérou) pré- (N=112) et post-intervention (N=112). Le statut hématologique des mères a été quantifié, le moment où le cordon est coupée a été chronométré et le niveau d'hémoglobine des enfants à été mesuré. La coupure du cordon a été retardée de manière significative de 113 secondes suite à l'intervention (βajusté=113.2 secondes; 95% IC =96.6-129.9). L'anémie maternelle a été identifiée comme un facteur modifiant. Chez les enfants nés d'une mère anémique, le rapport de cotes pour l'anémie est de 0.59 pour chaque minute où la coupure du cordon est retardée. Ces résultats supportent le retardement de la coupure du cordon comme mesure pouvant réduire l'anémie infantile

Interrelationships between soil-transmitted helminth infections, hemoglobin levels and child development: a longitudinal cohort study

Background: Soil-transmitted helminth (STH) infections are intestinal parasites that cause important disease burden primarily through intestinal bleeding, anemia, and competition for micronutrients. It has been proposed that STH infections affect child development, potentially due to mediation by iron levels. Limited research has been conducted on this topic in preschool children and the need to understand if STH infections affect child development has recently been emphasized. The overall objective of the current thesis, therefore, was to determine if, and how, STH infections affect child development in preschool children.Methods: A longitudinal cohort study was conducted in Iquitos, Peru between September 2011 and July 2016. Children, originally recruited at one year of age into a randomized controlled trial, were followed-up annually to five years of age. STH infection was measured at all study visits and child development was assessed annually in 880 children. Anthropometry was measured at all study visits and hemoglobin levels were measured at the three to five years of age time points. Linear regression models were used to determine the effect of the number of detected STH infections between one and five years of age on IQ scores at five years of age. Hierarchical models were used to determine the effect of STH infections between one and two years of age on repeated measures of verbal and cognitive abilities at two to five years of age. Natural direct and indirect effects were estimated to determine if the association between Ascaris infection and child development was mediated by mean hemoglobin levels and malnutrition. Bayesian latent class analysis was used throughout to adjust for STH infection misclassification.Results: A total of 781 (88.8%) children were included in the analyses. In multivariable analysis, adjusted for STH infection misclassification, increasing numbers of Ascaris, Trichuris, hookworm and any STH infections between one and five years of age were associated with lower IQ scores at five years of age (between group differences in verbal IQ scores (95% Credible Interval (CrI)) for being infected with Ascaris infection two, three and four or five times compared to zero or one infection, were: -8.27 (-13.85, -3.10), -6.69 (-12.05, -2.05), and, -5.06 (-10.75, 0.05), respectively). Furthermore, children found infected with Ascaris infection and any STH infection between one and two years of age had lower cognitive and verbal scores between two and five years of age (between group cognitive score differences (95% CrI) for being infected with any STH once, and infected two or three times, compared to never infected, were: -4.31 (-10.64, -0.14) and -3.70 (-10.11, -0.11), respectively). The mediation analysis results suggest that the association between Ascaris infection between one and five years of age and total IQ score at five years of age is importantly mediated by hemoglobin levels (natural direct effects (95% CrI) and natural indirect effects (95% CrI), compared to 0 or 1 infection, were: -0.91 (-4.63, 2.82) and -4.25 (-6.92, -1.59) for the effect of 2 infections, respectively; -1.41 (-3.79, 0.98) and -1.17 (-1.95, -0.43) for the effect of 3 infections, respectively; and, -0.39 (-3.21, 2.41) and -2.65 (-4.32, -0.99) for the effect of 4 or 5 infections, respectively).Conclusion: These results document the adverse impact of STH infection at a young age on child development. The results also suggest that this effect is importantly mediated by hemoglobin levels. Adjusting for STH infection misclassification was essential in obtaining an accurate estimation of the magnitude of this impact. Future research should take this adjustment into consideration. STH control in combination with iron-enhancing nutritional interventions targeted to preschool children as of one year of age may contribute to lowering the disease burden associated with poor child development in STH-endemic countries.Mise en contexte: Les géohelminthiases sont des parasites intestinaux qui posent une charge de morbidité importante. Il a été proposé que les géohelminthiases affectent le développement de l'enfant, par un mécanisme susceptible d'être lié aux taux de fer. Des recherches limitées ont été entreprises sur ce sujet chez les enfants d'âge préscolaire et la nécessité de développer une meilleure compréhension du lien entre les géohelminthiases et le développement de l'enfant a récemment été soulignée. L'objectif général était de déterminer si, et comment, les géohelminthiases affectent le développement de l'enfant chez les enfants d'âge préscolaire.Méthodes: Une étude longitudinale de cohorte a été réalisée à Iquitos, au Pérou, entre septembre 2011 et juillet 2016. Les enfants, recrutés à l'origine pour un essai contrôlé randomisé à l'âge d'un an, ont été suivis sur une base annuelle jusqu'à l'âge de cinq ans. Les géohelminthiases ont été mesurées à chacune des visites et le développement de l'enfant a été évalué annuellement chez 880 enfants. Des modèles de régression linéaire ont été employés pour quantifier l'effet du nombre d'helminthiases détecté entre les âges de un et cinq ans sur les scores de QI obtenus à l'âge de cinq ans. Des effets naturels directs et indirects ont été estimés afin de déterminer si l'association entre l'infection à Ascaris et le développement de l'enfant avait été influencée par les taux moyens d'hémoglobine et la malnutrition. Une analyse de structure latente bayésienne a été effectuée tout au long de l'étude afin de corriger pour les erreurs de classification des géohelminthiases.Résultats: Au total, 781 (88.8%) enfants ont été inclus dans les analyses. Une analyse multi-variables, corrigée en fonction des erreurs de classification des géohelminthiases, a démontré une association entre un nombre croissant d'infections à Ascaris, Trichuris, ankylostomes et toute géohelminthiase entre les âges de un et cinq ans et des scores de QI inférieurs à l'âge de cinq ans (les différences entre groupes des scores QI verbaux (Interval crédible (ICr) à 95%) pour deux, trois, et quatre ou cinq infections à Ascaris, par rapport à zéro ou une seule infection, étaient: -8.27 (-13.85, -3.10), -6.69 (-12.05, -2.05), et -5.06 (-10.75, 0.05), respectivement). De plus, les enfants reconnus comme ayant été atteints d'infections à Ascaris et toute géohelminthiase entre les âges d'un et de deux ans ont obtenus des scores cognitifs et verbaux inférieurs entre les âges de deux et de cinq ans. Les résultats de l'analyse de médiation suggèrent que l'association entre l'infection à Ascaris entre les âges d'un et cinq ans et le score QI global obtenu à l'âge cinq ans est largement influencée par les taux d'hémoglobine (les effets naturels directs (ICr à 95%) et effets naturels indirects (ICR à 95%), par rapport à 0 ou 1 infection, étaient: -0.91 (-4.63, 2.82) et -4.25 (-6.92, -1.59) pour l'effet de deux infections, respectivement; -1.41 (-3.79, 0.98) et -1.17 (-1.95, -0.43) pour l'effet de trois infections, respectivement; et -0.39 (-3.21, 2.41) et -2.65 (-4.32, -0.99) pour l'effet de 4 ou 5 infections, respectivement.Conclusion: Ces résultats documentent l'impact négatif des géohelminthiases à un âge précoce sur le développement de l'enfant. Ces résultats suggèrent également que cet impact est largement influencé par les taux d'hémoglobine. L'application d'une correction pour les erreurs de classification des géohelminthiases s'est avérée essentielle afin d'obtenir une estimation précise de l'ampleur de cet impact. Les recherches futures devraient tenir compte de cette correction. Le contrôle des géohelminthiases couplé à des interventions nutritionnelles axées sur l'augmentation des taux de fer et ciblant les enfants d'âge préscolaire dès l'âge d'un an pourraient ainsi contribuer à réduire la charge de morbidité associée au sous-développement de l'enfant dans les pays où les géohelminthiases sont endémiques

Impact of Health Education on Soil-Transmitted Helminth Infections in Schoolchildren of the Peruvian Amazon: A Cluster-Randomized Controlled Trial

The World Health Organization (WHO) recommends including a health hygiene education component into school-based deworming programs to reduce intestinal worm re-infection in treated children; however, the effect of these types of educational interventions has not been adequately studied. In this study, we investigated the effect of a health hygiene education intervention within a deworming program targeting Grade 5 schoolchildren in Bélen, Peru, a highly worm-endemic area. Following baseline assessment, all children in 18 primary schools received deworming

Sustaining a hygiene education intervention to prevent and control geohelminth infections at schools in the Peruvian Amazon

The World Health Organization currently recommends that school-based deworming programs include health hygiene education as a complementary measure. However, the sustainability and long-term impact of such hygiene education had yet to be assessed. In July 2012, this cross-sectional study was conducted in 18 primary schools in the Peruvian Amazon to gauge continuing adherence to a health hygiene education intervention introduced 2 years earlier to reduce soil-transmitted helminth infections. Due in large part to high teacher turn-over, only 9 of 47 (19.1%) teachers were still implementing the intervention. Health hygiene education interventions must, therefore, be designed to ensure sustainability in order to contribute to the overall effectiveness of school-based deworming programs

Eficacia del albendazol en dosis única sobre las infecciones por helmintos transmitidos por el suelo en escolares de una comunidad de Iquitos, Perú

Objectives. To determine the efficacy of single-dose albendazole (400 mg) for soil-transmitted helminth infections (STH) in schoolchildren living in one community of the city of Iquitos, Perú. Materials and methods. Within the context of a randomized controlled trial performed in a peri-urban community of limited resources located in Iquitos in the Peruvian Amazon, stool specimens were collected from Grade 5 schoolchildren in 18 schools and analysed for STH prevalence and intensity. A total of 1,193 school-age children were then dewormed with single-dose albendazole (400 mg). Of the 909 children who were found positive with at least one STH infection, a random sample of 385 was followed two weeks later when a second stool specimen was collected and analyzed. Results. The efficacy of albendazole was satisfactory: for Ascaris lumbricoides, with an egg reduction rate (ERR) of 99.8%; (95% CI: 99.3-100); for hookworm, with an ERR of 93.6 %; (95% CI: 88.2-96.6) and, for Trichuris trichiura, with an ERR of 72.7 %; (95% CI: 58.5-79.1). Conclusions. These results are consistent with previous data published on the efficacy of albendazole and the directives of the World Health Organization. Future research should focus on improving the efficacy of the treatment strategies for Trichuris trichiura infection.Objetivos. Determinar la eficacia en dosis única del albendazol sobre las infecciones por helmintos transmitidos por el suelo (HTS) en escolares de una comunidad de la ciudad de Iquitos en Perú. Materiales y métodos. Dentro del contexto de un ensayo controlado aleatorizado realizado en una comunidad periurbana de escasos recursos, situada en Iquitos, en la Amazonía de Perú, se obtuvieron muestras de heces de escolares del quinto grado de primaria en 18 escuelas y se analizó la prevalencia y la intensidad de HTS. Un total de 1193 escolares fueron desparasitados con albendazol en dosis única (400 mg). De los 909 escolares que fueron encontrados positivos con al menos una infección por HTS, una muestra aleatoria de 385 fue seguida dos semanas más tarde, cuando se recolectó y analizó una segunda muestra de heces. Resultados. La eficacia del albendazol fue satisfactoria para las infecciones por Ascaris lumbricoides con una tasa de reducción de huevos (TRH) de 99,8%; IC 95: 99,3-100 y por anquilostomideos con una TRH de 93,6%, IC 95%: 88,2- 96,6 y por Trichuris trichiura con una TRH de 72,7%, IC 95: 58,5-79,1. Conclusiones. Estos resultados son indicativos de niveles satisfactorios de eficacia y son congruentes con datos publicados sobre la eficacia del albendazol y directivas de la Organización Mundial de la Salud. Futuras investigaciones deben centrarse en mejorar la eficacia de las estrategias de tratamiento para la infección por Trichuris trichiura

A longitudinal cohort study of soil-transmitted helminth infections during the second year of life and associations with reduced long-term cognitive and verbal abilities

<div><p>Background</p><p>Soil-transmitted helminth (STH) infection leads to malnutrition and anemia, and has been linked to impaired child development. Previous research on this topic is limited and mostly conducted in school-age children. The goal of this study was to determine the effect of the number of detected STH infections between one and two years of age on subsequent cognitive and verbal abilities, in a cohort of preschool children.</p><p>Methodology/Principal findings</p><p>A longitudinal cohort study was conducted in 880 children in Iquitos, Peru between September 2011 and July 2016. Children were recruited at one year of age and followed up at 18 months and then annually between two and five years of age. STH infection was measured with the Kato-Katz technique or the direct smear technique. Child development was measured with the Bayley Scales of Infant and Toddler Development-III at the one to three-year visits and with the Wechsler Preschool and Primary Scale of Intelligence-III at the four and five-year visits. Hierarchical multivariable linear regression models were used to account for the repeated outcome measures for each child and Bayesian latent class analysis was used to adjust for STH misclassification. Children found infected with any STH infection between one and two years of age had lower cognitive scores between two and five years of age (between group score differences (95% credible intervals) for infected once, and infected two or three times, compared to never infected: -4.31 (-10.64, -0.14) and -3.70 (-10.11, -0.11), respectively). Similar results were found for <i>Ascaris</i> infection and for verbal scores.</p><p>Conclusions/Significance</p><p>An association was found between having been infected with <i>Ascaris</i> or any STH between one and two years of age and lower cognitive and verbal abilities later in childhood. These results suggest that targeting children for STH control as of one year of age is particularly important.</p></div