A randomized controlled trial of the effect of antihelminthic treatment and micronutrient fortification on health status and school performance of rural primary school children

Effects of Iron-Fortified Foods on the Nutritional Status of Children Residing in Regions Vulnerable to Parasitic Diseases: A Systematic Review

Parasitic infections (PIs) remain a public health concern among school-age children living in areas of greater socioeconomic vulnerability, especially in Brazil, Russia, India, China, and South Africa. PIs can promote nutritional deficiencies, increasing the risk of anemia and impaired physical and cognitive development. Thus, fortified foods have been considered as a promising strategy for improving the nutritional status of children and preventing PI complications. This systematic review aimed to present the effects of iron-fortified foods for deworming and improving blood parameters in schoolchildren residing in areas that are vulnerable to PIs. This review is based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines of randomized clinical trials addressing the use of fortified foods and micronutrients in children living in areas endemic for PIs. The PubMed, LILACS, Scopus, and Cochrane databases were searched to identify articles published between 2000 and 2020. A total of 153 records were retrieved from the databases, 10 of which were considered eligible for this study. On the basis of our analysis, most of the selected studies showed that the inclusion of fortified foods in the diet improved blood and infectious parameters. Therefore, fortified foods can be used as an important tool for controlling the adverse outcomes of PIs among children living in areas of greater vulnerability. However, more studies on this topic are needed to provide more evidence and consolidate strategies using iron-fortified food.

Interventions for Neglected Tropical Diseases Among Children and Adolescents: A Meta-analysis

BACKGROUND

Neglected tropical diseases (NTDs) are a group of communicable diseases affecting the poorest populations around the world.

OBJECTIVE

To assess the effectiveness of interventions, including mass drug administration (MDA), water, sanitation, and hygiene (WASH), vector control, health education, and micronutrients supplementation, for NTDs among children and adolescents.

METHODS

We conducted a literature search on the Cochrane Controlled Trials Register, Medline, and other databases until December 2020. We included randomized controlled trials and quasi-experimental studies conducted among children and adolescents. Two authors independently screened studies for relevance. Two authors independently extracted data, assessed the risk of bias, performed metaanalysis, and rated the quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation.

RESULTS

We included 155 studies (231 articles) involving 262 299 participants. For soil-transmitted helminthiasis, MDA may reduce the prevalence of Ascaris, Trichuris, and hookworm by 58%, 36%, and 57%, respectively. We are uncertain of the effect of health education, WASH, and iron supplementation on soil-transmitted helminthiasis prevalence. For Schistosomiasis, health education probably reduces the intensity and prevalence of S. mansoni, whereas micronutrient supplementation may reduce anemia prevalence and the infection intensity of S. hematobium compared with no supplementation. We are uncertain of the effect of MDA and vector control on Schistosomiasis outcomes. For trachoma, health education probably reduces the prevalence of active Trachoma, whereas we are uncertain of the effect of MDA, WASH, and vector control on Trachoma outcomes. There is limited data on the effectiveness of interventions for NTDs targeting children and adolescents.

CONCLUSION

Future studies are needed to evaluate the relative effectiveness and cost-effectiveness of various interventions specifically targeting children and adolescents.

Food fortification with multiple micronutrients: impact on health outcomes in general population

BACKGROUND

Vitamins and minerals are essential for growth and maintenance of a healthy body, and have a role in the functioning of almost every organ. Multiple interventions have been designed to improve micronutrient deficiency, and food fortification is one of them.

OBJECTIVES

To assess the impact of food fortification with multiple micronutrients on health outcomes in the general population, including men, women and children.

SEARCH METHODS

We searched electronic databases up to 29 August 2018, including the Cochrane Central Register of Controlled Trial (CENTRAL), the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register and Cochrane Public Health Specialised Register; MEDLINE; Embase, and 20 other databases, including clinical trial registries. There were no date or language restrictions. We checked reference lists of included studies and relevant systematic reviews for additional papers to be considered for inclusion.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster-RCTs, quasi-randomised trials, controlled before-after (CBA) studies and interrupted time series (ITS) studies that assessed the impact of food fortification with multiple micronutrients (MMNs). Primary outcomes included anaemia, micronutrient deficiencies, anthropometric measures, morbidity, all-cause mortality and cause-specific mortality. Secondary outcomes included potential adverse outcomes, serum concentration of specific micronutrients, serum haemoglobin levels and neurodevelopmental and cognitive outcomes. We included food fortification studies from both high-income and low- and middle-income countries (LMICs).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened, extracted and quality-appraised the data from eligible studies. We carried out statistical analysis using Review Manager 5 software. We used random-effects meta-analysis for combining data, as the characteristics of study participants and interventions differed significantly. We set out the main findings of the review in 'Summary of findings' tables, using the GRADE approach.

MAIN RESULTS

We identified 127 studies as relevant through title/abstract screening, and included 43 studies (48 papers) with 19,585 participants (17,878 children) in the review. All the included studies except three compared MMN fortification with placebo/no intervention. Two studies compared MMN fortification versus iodised salt and one study compared MMN fortification versus calcium fortification alone. Thirty-six studies targeted children; 20 studies were conducted in LMICs. Food vehicles used included staple foods, such as rice and flour; dairy products, including milk and yogurt; non-dairy beverages; biscuits; spreads; and salt. Fourteen of the studies were fully commercially funded, 13 had partial-commercial funding, 14 had non-commercial funding and two studies did not specify the source of funding. We rated all the evidence as of low to very low quality due to study limitations, imprecision, high heterogeneity and small sample size. When compared with placebo/no intervention, MMN fortification may reduce anaemia by 32% (risk ratio (RR) 0.68, 95% confidence interval (CI) 0.56 to 0.84; 11 studies, 3746 participants; low-quality evidence), iron deficiency anaemia by 72% (RR 0.28, 95% CI 0.19 to 0.39; 6 studies, 2189 participants; low-quality evidence), iron deficiency by 56% (RR 0.44, 95% CI 0.32 to 0.60; 11 studies, 3289 participants; low-quality evidence); vitamin A deficiency by 58% (RR 0.42, 95% CI 0.28 to 0.62; 6 studies, 1482 participants; low-quality evidence), vitamin B2 deficiency by 64% (RR 0.36, 95% CI 0.19 to 0.68; 1 study, 296 participants; low-quality evidence), vitamin B6 deficiency by 91% (RR 0.09, 95% CI 0.02 to 0.38; 2 studies, 301 participants; low-quality evidence), vitamin B12 deficiency by 58% (RR 0.42, 95% CI 0.25 to 0.71; 3 studies, 728 participants; low-quality evidence), weight-for-age z-scores (WAZ) (mean difference (MD) 0.1, 95% CI 0.02 to 0.17; 8 studies, 2889 participants; low-quality evidence) and weight-for-height/length z-score (WHZ/WLZ) (MD 0.1, 95% CI 0.02 to 0.18; 6 studies, 1758 participants; low-quality evidence). We are uncertain about the effect of MMN fortification on zinc deficiency (RR 0.84, 95% CI 0.65 to 1.08; 5 studies, 1490 participants; low-quality evidence) and height/length-for-age z-score (HAZ/LAZ) (MD 0.09, 95% CI 0.01 to 0.18; 8 studies, 2889 participants; low-quality evidence). Most of the studies in this comparison were conducted in children. Subgroup analyses of funding sources (commercial versus non-commercial) and duration of intervention did not demonstrate any difference in effects, although this was a relatively small number of studies and the possible association between commercial funding and increased effect estimates has been demonstrated in the wider health literature. We could not conduct subgroup analysis by food vehicle and funding; since there were too few studies in each subgroup to draw any meaningful conclusions. When we compared MMNs versus iodised salt, we are uncertain about the effect of MMN fortification on anaemia (R 0.86, 95% CI 0.37 to 2.01; 1 study, 88 participants; very low-quality evidence), iron deficiency anaemia (RR 0.40, 95% CI 0.09 to 1.83; 2 studies, 245 participants; very low-quality evidence), iron deficiency (RR 0.98, 95% CI 0.82 to 1.17; 1 study, 88 participants; very low-quality evidence) and vitamin A deficiency (RR 0.19, 95% CI 0.07 to 0.55; 2 studies, 363 participants; very low-quality evidence). Both of the studies were conducted in children. Only one study conducted in children compared MMN fortification versus calcium fortification. None of the primary outcomes were reported in the study. None of the included studies reported on morbidity, adverse events, all-cause or cause-specific mortality.

AUTHORS' CONCLUSIONS

The evidence from this review suggests that MMN fortification when compared to placebo/no intervention may reduce anaemia, iron deficiency anaemia and micronutrient deficiencies (iron, vitamin A, vitamin B2 and vitamin B6). We are uncertain of the effect of MMN fortification on anthropometric measures (HAZ/LAZ, WAZ and WHZ/WLZ). There are no data to suggest possible adverse effects of MMN fortification, and we could not draw reliable conclusions from various subgroup analyses due to a limited number of studies in each subgroup. We remain cautious about the level of commercial funding in this field, and the possibility that this may be associated with higher effect estimates, although subgroup analysis in this review did not demonstrate any impact of commercial funding. These findings are subject to study limitations, imprecision, high heterogeneity and small sample sizes, and we rated most of the evidence low to very low quality. and hence no concrete conclusions could be drawn from the findings of this review.

Mass deworming for improving health and cognition of children in endemic helminth areas: A systematic review and individual participant data network meta-analysis

Background

Soil transmitted (or intestinal) helminths and schistosomes affect millions of children worldwide.

Objectives

To use individual participant data network meta-analysis (NMA) to explore the effects of different types and frequency of deworming drugs on anaemia, cognition and growth across potential effect modifiers.

Search Methods

We developed a search strategy with an information scientist to search MEDLINE, CINAHL, LILACS, Embase, the Cochrane Library, Econlit, Internet Documents in Economics Access Service (IDEAS), Public Affairs Information Service (PAIS), Social Services Abstracts, Global Health CABI and CAB Abstracts up to March 27, 2018. We also searched grey literature, websites, contacted authors and screened references of relevant systematic reviews.

Selection Criteria

We included randomised and quasirandomised deworming trials in children for deworming compared to placebo or other interventions with data on baseline infection.

Data Collection and Analysis

We conducted NMA with individual participant data (IPD), using a frequentist approach for random-effects NMA. The covariates were: age, sex, weight, height, haemoglobin and infection intensity. The effect estimate chosen was the mean difference for the continuous outcome of interest.

Results

We received data from 19 randomized controlled trials with 31,945 participants. Overall risk of bias was low. There were no statistically significant subgroup effects across any of the potential effect modifiers. However, analyses showed that there may be greater effects on weight for moderate to heavily infected children (very low certainty evidence).

Authors' Conclusions

This analysis reinforces the case against mass deworming at a population-level, finding little effect on nutritional status or cognition. However, children with heavier intensity infections may benefit more. We urge the global community to adopt calls to make data available in open repositories to facilitate IPD analyses such as this, which aim to assess effects for the most vulnerable individuals.

Public health deworming programmes for soil-transmitted helminths in children living in endemic areas

BACKGROUND

The World Health Organization (WHO) recommends treating all school children at regular intervals with deworming drugs in areas where helminth infection is common. Global advocacy organizations claim routine deworming has substantive health and societal effects beyond the removal of worms. In this update of the 2015 edition we included six new trials, additional data from included trials, and addressed comments and criticisms.

OBJECTIVES

To summarize the effects of public health programmes to regularly treat all children with deworming drugs on child growth, haemoglobin, cognition, school attendance, school performance, physical fitness, and mortality.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; Embase; LILACS; the metaRegister of Controlled Trials (mRCT); reference lists; and registers of ongoing and completed trials up to 19 September 2018.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs that compared deworming drugs for soil-transmitted helminths (STHs) with placebo or no treatment in children aged 16 years or less, reporting on weight, height, haemoglobin, and formal tests of cognition. We also sought data on other measures of growth, school attendance, school performance, physical fitness, and mortality.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed the trials for inclusion, risk of bias, and extracted data. We analysed continuous data using the mean difference (MD) with 95% confidence intervals (CIs). Where data were missing, we contacted trial authors. We stratified the analysis based on the background burden of STH infection. We used outcomes at time of longest follow-up. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We identified 51 trials, including 10 cluster-RCTs, that met the inclusion criteria. One trial evaluating mortality included over one million children, and the remaining 50 trials included a total of 84,336 participants. Twenty-four trials were in populations categorized as high burden, including nine trials in children selected because they were helminth-stool positive; 18 with intermediate burden; and nine as low burden.First or single dose of deworming drugsFourteen trials reported on weight after a single dose of deworming drugs (4970 participants, 14 RCTs). The effects were variable. There was little or no effect in studies conducted in low and intermediate worm burden groups. In the high-burden group, there was little or no effect in most studies, except for a large effect detected from one study area in Kenya reported in two trials carried out over 30 years ago. These trials result in qualitative heterogeneity and uncertainty in the meta-analysis across all studies (I2 statistic = 90%), with GRADE assessment assessed as very low-certainty, which means we do not know if a first dose or single dose of deworming impacts on weight.For height, most studies showed little or no effect after a single dose, with one of the two trials in Kenya from 30 years ago showing a large average difference (2621 participants, 10 trials, low-certainty evidence). Single dose probably had no effect on average haemoglobin (MD 0.10 g/dL, 95% CI 0.03 lower to 0.22 higher; 1252 participants, five trials, moderate-certainty evidence), or on average cognition (1596 participants, five trials, low-certainty evidence). The data are insufficient to know if there is an effect on school attendance and performance (304 participants, one trial, low-certainty evidence), or on physical fitness (280 participants, three trials, very low-certainty evidence). No trials reported on mortality.Multiple doses of deworming drugsThe effect of regularly treating children with deworming drugs given every three to six months on weight was reported in 18 trials, with follow-up times of between six months and three years; there was little or no effect on average weight in all but two trials, irrespective of worm prevalence-intensity. The two trials with large average weight gain included one in the high burden area in Kenya carried out over 30 years ago, and one study from India in a low prevalence area where subsequent studies in the same area did not show an effect. This heterogeneity causes uncertainty in any meta-analysis (I2 = 78%). Post-hoc analysis excluding trials published prior to 2000 gave an estimate of average difference in weight gain of 0.02 kg (95%CI from 0.04 kg loss to 0.08 gain, I2 = 0%). Thus we conclude that we do not know if repeated doses of deworming drugs impact on average weight, with a fewer older studies showing large gains, and studies since 2000 showing little or no average gain.Regular treatment probably had little or no effect on the following parameters: average height (MD 0.02 cm higher, 95% CI 0.09 lower to 0.13 cm higher; 13,700 participants, 13 trials, moderate-certainty evidence); average haemoglobin (MD 0.01 g/dL lower; 95% CI 0.05 g/dL lower to 0.07 g/dL higher; 5498 participants, nine trials, moderate-certainty evidence); formal tests of cognition (35,394 participants, 8 trials, moderate-certainty evidence); school performance (34,967 participants, four trials, moderate-certainty evidence). The evidence assessing an effect on school attendance is inconsistent, and at risk of bias (mean attendance 2% higher, 95% CI 5% lower to 8% higher; 20,650 participants, three trials, very low-certainty evidence). No trials reported on physical fitness. No effect was shown on mortality (1,005,135 participants, three trials, low-certainty evidence).

AUTHORS' CONCLUSIONS

Public health programmes to regularly treat all children with deworming drugs do not appear to improve height, haemoglobin, cognition, school performance, or mortality. We do not know if there is an effect on school attendance, since the evidence is inconsistent and at risk of bias, and there is insufficient data on physical fitness. Studies conducted in two settings over 20 years ago showed large effects on weight gain, but this is not a finding in more recent, larger studies. We would caution against selecting only the evidence from these older studies as a rationale for contemporary mass treatment programmes as this ignores the recent studies that have not shown benefit.The conclusions of the 2015 edition have not changed in this update.

Health and educational achievement of school-aged children: The impact of anaemia and iron status on learning

BACKGROUND

Anaemia is a common blood disorder in children and is known to cause complications such as lethargy and stress on bodily organs. Children from disadvantaged communities often fail to achieve their age-related potential with iron deficiency anaemia stated as a risk factor through causing inattentiveness and learning problems. Limited evidence exists for the adverse effects of iron deficiency anaemia on the developing child's brain from South African studies.

AIM

The objective of this study was to determine the local prevalence of anaemia and iron deficiency and to examine their association with psychomotor development and school performance in school-aged children.

SETTING

This study was conducted in a peri-urban disadvantaged community from KwaZulu-Natal, South Africa.

METHODS

Children aged 6 to 8 years from KwaZulu-Natal were enrolled (n = 184). Three parameters of assessment were used: clinical data, biochemical data (haemoglobin levels and iron studies) and school performance (interviews with caregivers, teachers and the children). Anaemia presence and iron deficiency were the hypothesised mediating variables through which growth, development and school performance were influenced.

RESULTS

A high point prevalence of anaemia (23.4%), iron deficiency anaemia (4.9%) and helminth infection (27.1%) was identified. Impaired cognitive assessment scores (20.7%) were prevalent in the children sampled. Behavioural problems (4.3%), poor memory function (4.3%) and impaired attention (1.1%) were of low prevalence. Anaemia and iron deficiency were both associated with impaired fine motor skills (p < 0.05). Anaemia was significantly associated with low cognitive scores (p = 0.01). Neither anaemia, iron status nor helminth infection significantly predicted school performance in the children sampled.

CONCLUSIONS

The point prevalence of anaemia and iron deficiency among the sampled children was higher than the national prevalence. The sample size was however inadequate for drawing statistical conclusions about psychomotor development and school performance because of the low prevalence of the different outcomes that were examined. Practical challenges faced in conducting this investigation in rural South African schools were discussed.

Fortification of staple foods with vitamin A for vitamin A deficiency

BACKGROUND

Vitamin A deficiency is a significant public health problem in many low- and middle-income countries, especially affecting young children, women of reproductive age, and pregnant women. Fortification of staple foods with vitamin A has been used to increase vitamin A consumption among these groups.

OBJECTIVES

To assess the effects of fortifying staple foods with vitamin A for reducing vitamin A deficiency and improving health-related outcomes in the general population older than two years of age.

SEARCH METHODS

We searched the following international databases with no language or date restrictions: Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 6) in the Cochrane Library; MEDLINE and MEDLINE In Process OVID; Embase OVID; CINAHL Ebsco; Web of Science (ISI) SCI, SSCI, CPCI-exp and CPCI-SSH; BIOSIS (ISI); POPLINE; Bibliomap; TRoPHI; ASSIA (Proquest); IBECS; SCIELO; Global Index Medicus - AFRO and EMRO; LILACS; PAHO; WHOLIS; WPRO; IMSEAR; IndMED; and Native Health Research Database. We also searched clinicaltrials.gov and the International Clinical Trials Registry Platform to identify ongoing and unpublished studies. The date of the last search was 19 July 2018.

SELECTION CRITERIA

We included individually or cluster-randomised controlled trials (RCTs) in this review. The intervention included fortification of staple foods (sugar, edible oils, edible fats, maize flour or corn meal, wheat flour, milk and dairy products, and condiments and seasonings) with vitamin A alone or in combination with other vitamins and minerals. We included the general population older than two years of age (including pregnant and lactating women) from any country.

DATA COLLECTION AND ANALYSIS

Two authors independently screened and assessed eligibility of studies for inclusion, extracted data from included studies and assessed their risk of bias. We used standard Cochrane methodology to carry out the review.

MAIN RESULTS

We included 10 randomised controlled trials involving 4455 participants. All the studies were conducted in low- and upper-middle income countries where vitamin A deficiency was a public health issue. One of the included trials did not contribute data to the outcomes of interest.Three trials compared provision of staple foods fortified with vitamin A versus unfortified staple food, five trials compared provision of staple foods fortified with vitamin A plus other micronutrients versus unfortified staple foods, and two trials compared provision of staple foods fortified with vitamin A plus other micronutrients versus no intervention. No studies compared staple foods fortified with vitamin A alone versus no intervention.The duration of interventions ranged from three to nine months. We assessed six studies at high risk of bias overall. Government organisations, non-governmental organisations, the private sector, and academic institutions funded the included studies; funding source does not appear to have distorted the results.Staple food fortified with vitamin A versus unfortified staple food We are uncertain whether fortifying staple foods with vitamin A alone makes little or no difference for serum retinol concentration (mean difference (MD) 0.03 μmol/L, 95% CI -0.06 to 0.12; 3 studies, 1829 participants; I² = 90%, very low-certainty evidence). It is uncertain whether vitamin A alone reduces the risk of subclinical vitamin A deficiency (risk ratio (RR) 0.45, 95% CI 0.19 to 1.05; 2 studies; 993 participants; I² = 33%, very low-certainty evidence). The certainty of the evidence was mainly affected by risk of bias, imprecision and inconsistency.It is uncertain whether vitamin A fortification reduces clinical vitamin A deficiency, defined as night blindness (RR 0.11, 95% CI 0.01 to 1.98; 1 study, 581 participants, very low-certainty evidence). The certainty of the evidence was mainly affected by imprecision, inconsistency, and risk of bias.Staple foods fortified with vitamin A versus no intervention No studies provided data for this comparison.Staple foods fortified with vitamin A plus other micronutrients versus same unfortified staple foods Fortifying staple foods with vitamin A plus other micronutrients may not increase the serum retinol concentration (MD 0.08 μmol/L, 95% CI -0.06 to 0.22; 4 studies; 1009 participants; I² = 95%, low-certainty evidence). The certainty of the evidence was mainly affected by serious inconsistency and risk of bias.In comparison to unfortified staple foods, fortification with vitamin A plus other micronutrients probably reduces the risk of subclinical vitamin A deficiency (RR 0.27, 95% CI 0.16 to 0.49; 3 studies; 923 participants; I² = 0%; moderate-certainty evidence). The certainty of the evidence was mainly affected by serious risk of bias.Staple foods fortified with vitamin A plus other micronutrients versus no interventionFortification of staple foods with vitamin A plus other micronutrients may increase serum retinol concentration (MD 0.22 μmol/L, 95% CI 0.15 to 0.30; 2 studies; 318 participants; I² = 0%; low-certainty evidence). When compared to no intervention, it is uncertain whether the intervention reduces the risk of subclinical vitamin A deficiency (RR 0.71, 95% CI 0.52 to 0.98; 2 studies; 318 participants; I² = 0%; very low-certainty evidence) . The certainty of the evidence was affected mainly by serious imprecision and risk of bias.No trials reported on the outcomes of all-cause morbidity, all-cause mortality, adverse effects, food intake, congenital anomalies (for pregnant women), or breast milk concentration (for lactating women).

AUTHORS' CONCLUSIONS

Fortifying staple foods with vitamin A alone may make little or no difference to serum retinol concentrations or the risk of subclinical vitamin A deficiency. In comparison with provision of unfortified foods, provision of staple foods fortified with vitamin A plus other micronutrients may not increase serum retinol concentration but probably reduces the risk of subclinical vitamin A deficiency.Compared to no intervention, staple foods fortified with vitamin A plus other micronutrients may increase serum retinol concentration, although it is uncertain whether the intervention reduces the risk of subclinical vitamin A deficiency as the certainty of the evidence has been assessed as very low.It was not possible to estimate the effect of staple food fortification on outcomes such as mortality, morbidity, adverse effects, congenital anomalies, or breast milk vitamin A, as no trials included these outcomes.The type of funding source for the studies did not appear to distort the results from the analysis.

Evaluating the impact of integrated development: are we asking the right questions? A systematic review

Background: Emerging global transformations - including a new Sustainable Development Agenda - are revealing increasingly interrelated goals and challenges, poised to be addressed by similarly integrated, multi-faceted solutions. Research to date has focused on determining the effectiveness of these approaches, yet a key question remains: are synergistic effects produced by integrating two or more sectors?  We systematically reviewed impact evaluations on integrated development interventions to assess whether synergistic, amplified impacts are being measured and evaluated.

Methods: The International Initiative for Impact Evaluation’s (3ie) Impact Evaluation Repository comprised our sampling frame (n = 4,339). Following PRISMA guidelines, we employed a three-stage screening and review process.

Results: We identified 601 journal articles that evaluated integrated interventions. Seventy percent used a randomized design to assess impact with regard to whether the intervention achieved its desired outcomes. Only 26 of these evaluations, however, used a full factorial design to statistically detect any synergistic effects produced by integrating sectors. Of those, seven showed synergistic effects.

Conclusions: To date, evaluations of integrated development approaches have demonstrated positive impacts in numerous contexts, but gaps remain with regard to documenting whether integrated programming produces synergistic, amplified outcomes. Research on these program models needs to extend beyond impact only, and more explicitly examine and measure the synergies and efficiencies associated with linking two or more sectors. Doing so will be critical for identifying effective integrated development strategies that will help achieve the multi-sector SDG agenda.

Evaluating integrated development: are we asking the right questions? A systematic review

Background: Emerging global transformations - including a new Sustainable Development Agenda - are revealing increasingly interrelated goals and challenges, poised to be addressed by similarly integrated, multi-faceted solutions. Research to date has focused on determining the effectiveness of these approaches, yet a key question remains: are synergistic effects produced by integrating two or more sectors?  We systematically reviewed impact evaluations on integrated development interventions to assess whether synergistic, amplified impacts are being measured and evaluated. Methods: The International Initiative for Impact Evaluation’s (3ie) Impact Evaluation Repository comprised our sampling frame (n = 4,339). Following PRISMA guidelines, we employed a three-stage screening and review process. Results: We identified 601 journal articles that evaluated integrated interventions. Seventy percent used a randomized design to assess impact with regard to whether the intervention achieved its desired outcomes. Only 26 of these evaluations, however, used a full factorial design, the only design capable of statistically detecting synergistic effects produced by integrating sectors. Of those, seven showed synergistic effects. Conclusions: To date, evaluations of integrated development approaches have demonstrated positive impacts in numerous contexts, but gaps remain with regard to documenting whether integrated programming produces synergistic, amplified outcomes. Research on these program models needs to extend beyond impact only, and more explicitly examine and measure the synergies and efficiencies associated with linking two or more sectors. Doing so will be critical for identifying effective integrated development strategies that will help achieve the multi-sector SDG agenda.

Measuring the Effect of Soil-Transmitted Helminth Infections on Cognitive Function in Children: Systematic Review and Critical Appraisal of Evidence

Recently the role of soil-transmitted helminth (STH) infections in children's cognitive developmental impairment has been under scrutiny. We conducted a systematic review of the evidence for associations between STH infections and cognitive function of children using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. We aimed to identify the domains of cognitive function in three age strata (<24months, 24-59months and ≥60months) and critically appraise the general design protocol of the studies, with a focus on the cognitive function measurement tools used. A total of 42 papers fulfilled the inclusion criteria, including 10 studies from a recent Cochrane review. Our findings demonstrate variation in tested domains, lack of consistency in the use of measurement tools and analysis of results. Cognitive function measures in children aged under 59months have been mainly limited to domains of gross motor, fine motor and language skills, whereas in children aged 60months and above most studies tested domains such as memory and processing speed. Even within the same age group the results on the association between STH infections and measures of cognitive development were often conflicting. The current study highlights the need for methodological consensus in the use of measurement tools and data analysis protocols if the effect of STH infections on cognitive function domains in children is to be correctly established. This will be an imperative next step to generate conclusive evidence of the role of STH infections in cognitive development in children.

Deworming drugs for soil-transmitted intestinal worms in children: effects on nutritional indicators, haemoglobin, and school performance

BACKGROUND

The World Health Organization (WHO) recommends treating all school children at regular intervals with deworming drugs in areas where helminth infection is common. As the intervention is often claimed to have important health, nutrition, and societal effects beyond the removal of worms, we critically evaluated the evidence on benefits.

OBJECTIVES

To summarize the effects of giving deworming drugs to children to treat soil-transmitted helminths on weight, haemoglobin, and cognition; and the evidence of impact on physical well-being, school attendance, school performance, and mortality.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register (14 April 2015); Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library (2015, Issue 4); MEDLINE (2000 to 14 April 2015); EMBASE (2000 to 14 April 2015); LILACS (2000 to 14 April 2015); the metaRegister of Controlled Trials (mRCT); and reference lists, and registers of ongoing and completed trials up to 14 April 2015.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs comparing deworming drugs for soil-transmitted helminths with placebo or no treatment in children aged 16 years or less, reporting on weight, haemoglobin, and formal tests of intellectual development. We also sought data on school attendance, school performance, and mortality. We included trials that combined health education with deworming programmes.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed the trials, evaluated risk of bias, and extracted data. We analysed continuous data using the mean difference (MD) with 95% confidence intervals (CIs). Where data were missing, we contacted trial authors. We used outcomes at time of longest follow-up. The evidence quality was assessed using GRADE. This edition of the Cochrane Review adds the DEVTA trial from India, and draws on an independent analytical replication of a trial from Kenya.

MAIN RESULTS

We identified 45 trials, including nine cluster-RCTs, that met the inclusion criteria. One trial evaluating mortality included over one million children, and the remaining 44 trials included a total of 67,672 participants. Eight trials were in children known to be infected, and 37 trials were carried out in endemic areas, including areas of high (15 trials), moderate (12 trials), and low prevalence (10 trials). Treating children known to be infectedTreating children known to be infected with a single dose of deworming drugs (selected by screening, or living in areas where all children are infected) may increase weight gain over the next one to six months (627 participants, five trials, low quality evidence). The effect size varied across trials from an additional 0.2 kg gain to 1.3 kg. There is currently insufficient evidence to know whether treatment has additional effects on haemoglobin (247 participants, two trials, very low quality evidence); school attendance (0 trials); cognitive functioning (103 participants, two trials, very low quality evidence), or physical well-being (280 participants, three trials, very low quality evidence). Community deworming programmesTreating all children living in endemic areas with a dose of deworming drugs probably has little or no effect on average weight gain (MD 0.04 kg less, 95% CI 0.11 kg less to 0.04 kg more; trials 2719 participants, seven trials, moderate quality evidence), even in settings with high prevalence of infection (290 participants, two trials). A single dose also probably has no effect on average haemoglobin (MD 0.06 g/dL, 95% CI -0.05 lower to 0.17 higher; 1005 participants, three trials, moderate quality evidence), or average cognition (1361 participants, two trials, low quality evidence).Similiarly, regularly treating all children in endemic areas with deworming drugs, given every three to six months, may have little or no effect on average weight gain (MD 0.08 kg, 95% CI 0.11 kg less to 0.27 kg more; 38,392 participants, 10 trials, low quality evidence). The effects were variable across trials; one trial from a low prevalence setting carried out in 1995 found an increase in weight, but nine trials carried out since then found no effect, including five from moderate and high prevalence areas.There is also reasonable evidence that regular treatment probably has no effect on average height (MD 0.02 cm higher, 95% CI 0.14 lower to 0.17 cm higher; 7057 participants, seven trials, moderate quality evidence); average haemoglobin (MD 0.02 g/dL lower; 95% CI 0.08 g/dL lower to 0.04 g/dL higher; 3595 participants, seven trials, low quality evidence); formal tests of cognition (32,486 participants, five trials, moderate quality evidence); exam performance (32,659 participants, two trials, moderate quality evidence); or mortality (1,005,135 participants, three trials, low quality evidence). There is very limited evidence assessing an effect on school attendance and the findings are inconsistent, and at risk of bias (mean attendance 2% higher, 95% CI 4% lower to 8% higher; 20,243 participants, two trials, very low quality evidence).In a sensitivity analysis that only included trials with adequate allocation concealment, there was no evidence of any effect for the main outcomes.

AUTHORS' CONCLUSIONS

Treating children known to have worm infection may have some nutritional benefits for the individual. However, in mass treatment of all children in endemic areas, there is now substantial evidence that this does not improve average nutritional status, haemoglobin, cognition, school performance, or survival.

Soil-Transmitted Helminths in Southwestern China: A Cross-Sectional Study of Links to Cognitive Ability, Nutrition, and School Performance among Children

Background

Empirical evidence suggests that the prevalence of soil-transmitted helminth (STH) infections in remote and poor rural areas is still high among children, the most vulnerable to infection. There is concern that STH infections may detrimentally affect children’s healthy development, including their cognitive ability, nutritional status, and school performance. Medical studies have not yet identified the exact nature of the impact STH infections have on children. The objective of this study is to examine the relationship between STH infections and developmental outcomes among a primary school-aged population in rural China.

Methodology/Principal Findings

We conducted a large-scale survey in Guizhou province in southwest China in May 2013. A total of 2,179 children aged 9-11 years living in seven nationally-designated poverty counties in rural China served as our study sample. Overall, 42 percent of the sample’s elementary school-aged children were infected with one or more of the three types of STH—Ascaris lumbricoides (ascaris), Trichuris trichuria (whipworm) and the hookworms Ancylostoma duodenale or Necator americanus. After controlling for socioeconomic status, we observed that infection with one or more STHs is associated with worse cognitive ability, worse nutritional status, and worse school performance than no infection. This study also presents evidence that children with Trichuris infection, either infection with Trichuris only or co-infected with Trichuris and Ascaris, experience worse cognitive, nutritional and schooling outcomes than their uninfected peers or children infected with only Ascaris.

Conclusions/Significance

We find that STH infection still poses a significant health challenge among children living in poor, rural, ethnic areas of southwest China. Given the important linkages we find between STH infection and a number of important child health and educational outcomes, we believe that our results will contribute positively to the debate surrounding the recent Cochrane report.

Empirical evidence suggests that the prevalence of soil-transmitted helminth (STH) infections in remote and poor rural areas is still high among children, the most vulnerable to infection. There is concern that STH infections may detrimentally affect children’s healthy development, including their cognitive ability, nutritional status, and school performance. Medical studies have not yet identified the exact nature of the impact STH infections have on children. The objective of this study is to examine the relationship between STH infections and developmental outcomes among a primary school-aged population in rural China. We conducted a large-scale survey in Guizhou province in southwest China in May, 2013. Overall, 42 percent of elementary school-aged children were infected with one or more of the three types of STH—Ascaris lumbricoides (ascaris), Trichuris trichuria (whipworm) and the hookworms Ancylostoma duodenale or Necator americanus. After controlling for socioeconomic status, we observed that children infected with one or more STHs have worse cognitive ability, worse nutritional status, and worse school performance than their uninfected peers. While not causal, this study also presents evidence that children with Trichuris infection, either infection with Trichuris only or co-infected with Trichuris and Ascaris, have worse cognitive, nutritional and schooling outcomes than their uninfected peers or children infected with only Ascaris. Given these important linkages, we hope that our results will contribute positively to the debate surrounding the recent Cochrane report.

Helminth infections and micronutrients in school-age children: a systematic review and meta-analysis

BACKGROUND

Helminth infections and micronutrient deficiencies are highly prevalent in developing countries. Neither condition typically causes overt disease, but they do lead to indirect morbidity such as impaired physical and cognitive development.

OBJECTIVE

We aimed to systematically review current evidence on the relation of helminth infections with micronutrient status in school-age children worldwide.

DESIGN

We included both observational studies and randomized controlled trials (RCTs). We applied a random-effects meta-analysis to estimate 1) cross-sectional associations between helminths and micronutrient status, 2) effects of anthelminthic treatment on micronutrient status, and 3) effects of micronutrient supplementation on helminth infection and reinfection.

RESULTS

Meta-analyses of observational studies showed an association between helminth infections and serum retinol [standardized mean difference (SMD): -0.30; 95% CI: -0.48, -0.13] but not serum ferritin (SMD: 0.00; 95% CI: -0.7, 0.7). Conversely, meta-analyses of anthelminthic treatment RCTs showed a positive effect on ferritin (SMD: 0.16; 95% CI: 0.09, 0.22) but not retinol (SMD: 0.04; 95% CI: -0.06, 0.14). The number of studies on micronutrients other than ferritin and retinol was not sufficient for pooling. Meta-analyses of micronutrient-supplementation RCTs showed only a modest protective effect for multimicronutrient interventions on helminth infection and reinfection rates (OR: 0.77; 95% CI: 0.61, 0.97).

CONCLUSIONS

In this review, we show evidence of distinct associations between helminth infections and micronutrients in school-age children. More studies are needed on micronutrients other than iron and vitamin A and on possible helminth species-specific effects. A thorough comprehension of the interplay between helminth infections and micronutrients will help guide integrated and sustainable intervention strategies in affected children worldwide.

Micronutrient fortification of food and its impact on woman and child health: a systematic review

BACKGROUND

Vitamins and minerals are essential for growth and metabolism. The World Health Organization estimates that more than 2 billion people are deficient in key vitamins and minerals. Groups most vulnerable to these micronutrient deficiencies are pregnant and lactating women and young children, given their increased demands. Food fortification is one of the strategies that has been used safely and effectively to prevent vitamin and mineral deficiencies.

METHODS

A comprehensive search was done to identify all available evidence for the impact of fortification interventions. Studies were included if food was fortified with a single, dual or multiple micronutrients and impact of fortification was analyzed on the health outcomes and relevant biochemical indicators of women and children. We performed a meta-analysis of outcomes using Review Manager Software version 5.1.

RESULTS

Our systematic review identified 201 studies that we reviewed for outcomes of relevance. Fortification for children showed significant impacts on increasing serum micronutrient concentrations. Hematologic markers also improved, including hemoglobin concentrations, which showed a significant rise when food was fortified with vitamin A, iron and multiple micronutrients. Fortification with zinc had no significant adverse impact on hemoglobin levels. Multiple micronutrient fortification showed non-significant impacts on height for age, weight for age and weight for height Z-scores, although they showed positive trends. The results for fortification in women showed that calcium and vitamin D fortification had significant impacts in the post-menopausal age group. Iron fortification led to a significant increase in serum ferritin and hemoglobin levels in women of reproductive age and pregnant women. Folate fortification significantly reduced the incidence of congenital abnormalities like neural tube defects without increasing the incidence of twinning. The number of studies pooled for zinc and multiple micronutrients for women were few, though the evidence suggested benefit. There was a dearth of evidence for the impact of fortification strategies on morbidity and mortality outcomes in women and children.

CONCLUSION

Fortification is potentially an effective strategy but evidence from the developing world is scarce. Programs need to assess the direct impact of fortification on morbidity and mortality.

Deworming drugs for soil-transmitted intestinal worms in children: effects on nutritional indicators, haemoglobin and school performance

BACKGROUND

The World Health Organization (WHO) recommends treating all school children at regular intervals with deworming drugs in areas where helminth infection is common. The WHO state this will improve nutritional status, haemoglobin, and cognition and thus will improve health, intellect, and school attendance. Consequently, it is claimed that school performance will improve, child mortality will decline, and economic productivity will increase. Given the important health and societal benefits attributed to this intervention, we sought to determine whether they are based on reliable evidence.

OBJECTIVES

To summarize the effects of giving deworming drugs to children to treat soil-transmitted intestinal worms (nematode geohelminths) on weight, haemoglobin, and cognition; and the evidence of impact on physical well being, school attendance, school performance, and mortality.

SEARCH METHODS

In February 2012, we searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, EMBASE, LILACS, mRCT, and reference lists, and registers of ongoing and completed trials.

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) and quasi-RCTs comparing deworming drugs for geohelminth worms with placebo or no treatment in children aged 16 years or less, reporting on weight, haemoglobin, and formal test of intellectual development. In cluster-RCTs treating communities or schools, we also sought data on school attendance, school performance, and mortality. We included trials that included health education with deworming.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed the trials, evaluated risk of bias, and extracted data. Continuous data were analysed using the mean difference (MD) with 95% confidence intervals (CI). Where data were missing, we contacted trial authors. We used GRADE to assess evidence quality, and this is reflected in the wording we used: high quality ("deworming improves...."); moderate quality ("deworming probably improves..."); low quality ("deworming may improve...."); and very low quality ("we don't know if deworming improves....").

MAIN RESULTS

We identified 42 trials, including eight cluster trials, that met the inclusion criteria. Excluding one trial where data are awaited, the 41 trials include 65,168 participants.Screening then treatingFor children known to be infected with worms (by screening), a single dose of deworming drugs may increase weight (0.58 kg, 95% CI 0.40 to 0.76, three trials, 139 participants; low quality evidence) and may increase haemoglobin (0.37 g/dL, 95% CI 0.1 to 0.64, two trials, 108 participants; low quality evidence), but we do not know if there is an effect on cognitive functioning (two trials, very low quality evidence).Single dose deworming for all childrenIn trials treating all children, a single dose of deworming drugs gave mixed effects on weight, with no effects evident in seven trials, but large effects in two (nine trials, 3058 participants, very low quality evidence). The two trials with a positive effect were from the same very high prevalence setting and may not be easily generalised elsewhere. Single dose deworming probably made little or no effect on haemoglobin (mean difference (MD) 0.06 g/dL, 95% CI -0.06 to 0.17, three trials, 1005 participants; moderate evidence), and may have little or no effect on cognition (two trials, low quality evidence).Mulitple dose deworming for all childrenOver the first year of follow up, multiple doses of deworming drugs given to all children may have little or no effect on weight (MD 0.06 kg, 95% CI -0.17 to 0.30; seven trials, 2460 participants; low quality evidence); haemoglobin, (mean 0.01 g/dL lower; 95% CI 0.14 lower to 0.13 higher; four trials, 807 participants; low quality evidence); cognition (three trials, 30,571 participants, low quality evidence); or school attendance (4% higher attendance; 95% CI -6 to 14; two trials, 30,243 participants; low quality evidence);For time periods beyond a year, there were five trials with weight measures. One cluster-RCT of 3712 children in a low prevalence area showed a large effect (average gain of 0.98 kg), whilst the other four trials did not show an effect, including a cluster-RCT of 27,995 children in a moderate prevalence area (five trials, 37,306 participants; low quality evidence). For height, we are uncertain whether there is an effect of deworming (-0.26 cm; 95% CI -0.84 to 0.31, three trials, 6652 participants; very low quality evidence). Deworming may have little or no effect on haemoglobin (0.00 g/dL, 95%CI -0.08 to 0.08, two trials, 1365 participants, low quality evidence); cognition (two trials, 3720 participants; moderate quality evidence). For school attendance, we are uncertain if there is an effect (mean attendance 5% higher, 95% CI -0.5 to 10.5, approximately 20,000 participants, very low quality evidence).Stratified analysis to seek subgroup effects into low, medium and high helminth endemicity areas did not demonstrate any pattern of effect. In a sensitivity analysis that only included trials with adequate allocation concealment, we detected no significant effects for any primary outcomes.One million children were randomized in a deworming trial from India with mortality as the primary outcome. This was completed in 2005 but the authors have not published the results.

AUTHORS' CONCLUSIONS

Screening children for intestinal helminths and then treating infected children appears promising, but the evidence base is small. Routine deworming drugs given to school children has been more extensively investigated, and has not shown benefit on weight in most studies, except for substantial weight changes in three trials conducted 15 years ago or more. Two of these trials were carried out in the same high prevalence setting. For haemoglobin and cognition, community deworming seems to have little or no effect, and the evidence in relation to school attendance, and school performance is generally poor, with no obvious or consistent effect. Our interpretation of this data is that it is probably misleading to justify contemporary deworming programmes based on evidence of consistent benefit on nutrition, haemoglobin, school attendance or school performance as there is simply insufficient reliable information to know whether this is so.

Effect of iron-fortified foods on hematologic and biological outcomes: systematic review of randomized controlled trials

BACKGROUND

The utility of iron fortification of food to improve iron deficiency, anemia, and biological outcomes is not proven unequivocally.

OBJECTIVES

The objectives were to evaluate 1) the effect of iron fortification on hemoglobin and serum ferritin and the prevalence of iron deficiency and anemia, 2) the possible predictors of a positive hemoglobin response, 3) the effect of iron fortification on zinc and iron status, and 4) the effect of iron-fortified foods on mental and motor development, anthropometric measures, and infections.

DESIGN

Randomized and pseudorandomized controlled trials that included food fortification or biofortification with iron were included.

RESULTS

Data from 60 trials showed that iron fortification of foods resulted in a significant increase in hemoglobin (0.42 g/dL; 95% CI: 0.28, 0.56; P < 0.001) and serum ferritin (1.36 μg/L; 95% CI: 1.23, 1.52; P < 0.001), a reduced risk of anemia (RR: 0.59; 95% CI: 0.48, 0.71; P < 0.001) and iron deficiency (RR: 0.48; 95% CI: 0.38, 0.62; P < 0.001), improvement in other indicators of iron nutriture, and no effect on serum zinc concentrations, infections, physical growth, and mental and motor development. Significant heterogeneity was observed for most of the evaluated outcomes. Sensitivity analyses and meta-regression for hemoglobin suggested a higher response with lower trial quality (suboptimal allocation concealment and blinding), use of condiments, and sodium iron edetate and a lower response when adults were included.

CONCLUSION

Consumption of iron-fortified foods results in an improvement in hemoglobin, serum ferritin, and iron nutriture and a reduced risk of remaining anemic and iron deficient.

Deworming drugs for soil-transmitted intestinal worms in children: effects on nutritional indicators, haemoglobin and school performance

BACKGROUND

The World Health Organization (WHO) recommends treating all school children at regular intervals with deworming drugs in areas where helminth infection is common. The WHO state this will improve nutritional status, haemoglobin, and cognition and thus will improve health, intellect, and school attendance. Consequently, it is claimed that school performance will improve, child mortality will decline, and economic productivity will increase. Given the important health and societal benefits attributed to this intervention, we sought to determine whether they are based on reliable evidence.

OBJECTIVES

To summarize the effects of giving deworming drugs to children to treat soil-transmitted intestinal worms (nematode geohelminths) on weight, haemoglobin, and cognition; and the evidence of impact on physical well being, school attendance, school performance, and mortality.

SEARCH METHODS

In February 2012, we searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, EMBASE, LILACS, mRCT, and reference lists, and registers of ongoing and completed trials.

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) and quasi-RCTs comparing deworming drugs for geohelminth worms with placebo or no treatment in children aged 16 years or less, reporting on weight, haemoglobin, and formal test of intellectual development. In cluster-RCTs treating communities or schools, we also sought data on school attendance, school performance, and mortality. We included trials that included health education with deworming.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed the trials, evaluated risk of bias, and extracted data. Continuous data were analysed using the mean difference (MD) with 95% confidence intervals (CI). Where data were missing, we contacted trial authors. We used GRADE to assess evidence quality, and this is reflected in the wording we used: high quality ("deworming improves...."); moderate quality ("deworming probably improves..."); low quality ("deworming may improve...."); and very low quality ("we don't know if deworming improves....").

MAIN RESULTS

We identified 42 trials, including eight cluster trials, that met the inclusion criteria. Excluding one trial where data are awaited, the 41 trials include 65,168 participants.For programmes that treat only children detected as infected (by screening), a single dose of deworming drugs probably increased weight (0.58 kg, 95% CI 0.40 to 0.76, three trials, 139 participants; moderate quality evidence) and may have increased haemoglobin (0.37 g/dL, 95% CI 0.1 to 0.64, two trials, 108 participants; low quality evidence), but we do not know if there is an effect on cognitive functioning (two trials, very low quality evidence).For a single dose of deworming drugs given to all children in endemic areas, there were mixed effects on weight, with no effects evident in seven trials, but large effects in two. Overall our analysis indicated that we are uncertain whether there was an effect on weight (nine trials, 3058 participants; very low quality evidence). For haemoglobin, deworming made little or no difference (0.02 g/dL, 95% CI -0.05 to 0.09, four trials, 1992 participants; low quality evidence), and we don't know if it improves cognition (one trial, very low quality evidence).For multiple doses of deworming drugs with follow up for up to one year given to all children in endemic areas, we are uncertain if there is an effect on weight (0.06 kg, 95% CI -0.17 to 0.30; seven trials, 2460 participants; very low quality evidence); cognition (three trials, very low quality evidence); or school attendance (4% higher attendance; 95% CI -6 to 14; two trials, 75 clusters and 143 individually randomized participants, very low quality evidence). For haemoglobin, the intervention may have little or no effect (mean 0.01 g/dL lower; 95% CI 0.14 lower to 0.13 higher; four trials, 807 participants; low quality evidence).For multiple doses of deworming drugs with follow up beyond one year given to all children in endemic areas there were five trials with weight measures. One cluster-RCT of 3712 children in a low prevalence area showed a large effect (average gain of 0.98kg), whilst the other four trials did not show an effect, including a cluster-RCT of 27,995 children in a moderate prevalence area. Overall, we are uncertain if there is an effect for weight (five trials, 302 clusters and 1045 individually randomized participants; very low quality evidence). For other outcomes, we are uncertain whether deworming affects height (-0.26 cm; 95%CI -0.84 to 0.31, three trials, 1219 participants); haemoglobin (0.02 g/dL, 95%CI 0.3 to 0.27, two trials, 1365 participants); cognition (two trials), or school attendance (mean attendance 5% higher, 95% CI -0.5 to 10.5, one trial, 50 clusters).Stratified analysis to seek subgroup effects into low, medium and high helminth endemicity areas did not demonstrate any pattern of effect. We did not detect any significant effects for any primary outcomes in a sensitivity analysis only including trials with adequate allocation concealment.One million children were randomized in a deworming trial from India with mortality as the primary outcome. This was completed in 2005 but the authors have not published the results.

AUTHORS' CONCLUSIONS

Screening children for intestinal helminths and then treating infected children appears promising, but the evidence base is small. Routine deworming drugs given to school children has been more extensively investigated, and has not shown benefit on weight in most studies, except for substantial weight changes in three trials conducted 15 years ago or more. Two of these trials were carried out in the same high prevalence setting. For haemoglobin, community deworming seems to have little or no effect, and the evidence in relation to cognition, school attendance, and school performance is generally poor, with no obvious or consistent effect. Our interpretation of this data is that it is probably misleading to justify contemporary deworming programmes based on evidence of consistent benefit on nutrition, haemoglobin, school attendance or school performance as there is simply insufficient reliable information to know whether this is so.

Treatment for Schistosoma japonicum, reduction of intestinal parasite load, and cognitive test score improvements in school-aged children

Background

To determine whether treatment of intestinal parasitic infections improves cognitive function in school-aged children, we examined changes in cognitive testscores over 18 months in relation to: (i) treatment-related Schistosoma japonicum intensity decline, (ii) spontaneous reduction of single soil-transmitted helminth (STH) species, and (iii) ≥2 STH infections among 253 S. japonicum-infected children.

Methodology

Helminth infections were assessed at baseline and quarterly by the Kato-Katz method. S. japonicum infection was treated at baseline using praziquantel. An intensity-based indicator of lower vs. no change/higher infection was defined separately for each helminth species and joint intensity declines of ≥2 STH species. In addition, S. japonicum infection-free duration was defined in four categories based on time of schistosome re-infection: >18 (i.e. cured), >12 to ≤18, 6 to ≤12 and ≤6 (persistently infected) months. There was no baseline treatment for STHs but their intensity varied possibly due to spontaneous infection clearance/acquisition. Four cognitive tests were administered at baseline, 6, 12, and 18 months following S. japonicum treatment: learning and memory domains of Wide Range Assessment of Memory and Learning (WRAML), verbal fluency (VF), and Philippine nonverbal intelligence test (PNIT). Linear regression models were used to relate changes in respective infections to test performance with adjustment for sociodemographic confounders and coincident helminth infections.

Principal Findings

Children cured (β = 5.8; P = 0.02) and those schistosome-free for >12 months (β = 1.5; P = 0.03) scored higher in WRAML memory and VF tests compared to persistently infected children independent of STH infections. A decline vs. no change/increase of any individual STH species (β:11.5–14.5; all P<0.01) and the joint decline of ≥2 STH (β = 13.1; P = 0.01) species were associated with higher scores in WRAML learning test independent of schistosome infection. Hookworm and Trichuris trichiura declines were independently associated with improvements in WRAML memory scores as was the joint decline in ≥2 STH species. Baseline coinfection by ≥2 STH species was associated with low PNIT scores (β = −1.9; P = 0.04).

Conclusion/Significance

Children cured/S. japonicum-free for >12 months post-treatment and those who experienced declines of ≥2 STH species scored higher in three of four cognitive tests. Our result suggests that sustained deworming and simultaneous control for schistosome and STH infections could improve children's ability to take advantage of educational opportunities in helminth-endemic regions.

Parasitic worm infections are associated with cognitive impairment and lower academic achievement for infected relative to uninfected children. However, it is unclear whether curing or reducing worm infection intensity improves child cognitive function. We examined the independent associations between: (i) Schistosoma japonicum infection-free duration, (ii) declines in single helminth species, and (iii) joint declines of ≥2 soil-transmitted helminth (STH) infections and improvements in four cognitive tests during18 months of follow-up. Enrolled were schistosome-infected school-aged children among whom coinfection with STH was common. All children were treated for schistosome infection only at enrolment with praziquantel. Children cured or schistosome-free for >12 months scored higher in memory and verbal fluency tests compared to persistently infected children. Likewise, declines of single and polyparasitic STH infections predicted higher scores in three of four tests. We conclude that reducing the intensity of certain helminth species and the frequency of multi-species STH infections may have long-term benefits for affected children's cognitive performance. The rapidity of schistosome re-infection and the ubiquity of concurrent multi-species infection highlight the importance of sustained deworming for both schistosome and STH infections to enhance the learning and educational attainment of children in helminth-endemic settings.

Multiple micronutrient supplementation for improving cognitive performance in children: systematic review of randomized controlled trials

BACKGROUND

Although multiple micronutrient interventions have been shown to benefit children's intellectual development, a thorough evaluation of the totality of evidence is currently lacking to direct public health policy.

OBJECTIVE

This study aimed to systematically review the present literature and to quantify the effect of multiple micronutrients on cognitive performance in schoolchildren.

METHODS

The Institute for Scientific Information Web of Knowledge and local medical databases were searched for trials published from 1970 to 2008. Randomized controlled trials that investigated the effect of > or =3 micronutrients compared with placebo on cognition in healthy children aged 0-18 y were included following protocol. Data were extracted by 2 independent researchers. The cognitive tests used in the trials were grouped into several cognitive domains (eg, fluid and crystallized intelligence), and pooled effect size estimates were calculated per domain. Heterogeneity was explored through sensitivity and meta-regression techniques.

RESULTS

Three trials were retrieved in children aged <5 y, and 17 trials were retrieved in children aged 5-16 y. For the older children, pooled random-effect estimates for intervention were 0.14 SD (95% CI: -0.02, 0.29; P = 0.083) for fluid intelligence and -0.03 SD (95% CI: -0.21, 0.15; P = 0.74) for crystallized intelligence, both of which were based on 12 trials. Four trials yielded an overall effect of 0.30 SD (95% CI: 0.01, 0.58; P = 0.044) for academic performance. For other cognitive domains, no significant effects were found.

CONCLUSIONS

Multiple micronutrient supplementation may be associated with a marginal increase in fluid intelligence and academic performance in healthy schoolchildren but not with crystallized intelligence. More research is required, however, before public health recommendations can be given.

Effect of fortification with multiple micronutrients and n-3 fatty acids on growth and cognitive performance in Indian schoolchildren: the CHAMPION (Children's Health and Mental Performance Influenced by Optimal Nutrition) Study

BACKGROUND

Fortification with multiple micronutrients has been shown to improve growth and cognitive performance among children in developing countries, but it is unknown whether higher concentrations are more effective than lower concentrations.

OBJECTIVE

We compared the effect of 2 different concentrations of a combination of micronutrients and n-3 (omega-3) fatty acids on indicators of growth and cognitive performance in low-income, marginally nourished schoolchildren in Bangalore, India.

DESIGN

In a 2-by-2 factorial, double-blind, randomized controlled trial, 598 children aged 6-10 y were individually allocated to 1 of 4 intervention groups to receive foods fortified with either 100% or 15% of the Recommended Dietary Allowance of micronutrients in combination with either 900 mg alpha-linolenic acid plus 100 mg docosahexaenoic acid or 140 mg alpha-linolenic acid for 12 mo. Anthropometric and biochemical assessments were performed at baseline and 12 mo. Cognitive performance was measured at baseline and at 6 and 12 mo.

RESULTS

The high micronutrient treatment significantly improved linear growth at 12 mo (0.19 cm; 0.01, 0.36) and short-term memory at 6 mo (0.11 SD; 0.01, 0.20) and was less beneficial on fluid reasoning at 6 (-0.10 SD; -0.17, -0.03) and 12 (-0.12 SD; -0.20, -0.04) mo than was the low micronutrient treatment, whereas no differences were observed on weight, retrieval ability, cognitive speediness, and overall cognitive performance. No significant differences were found between the n-3 treatments.

CONCLUSIONS

The high micronutrient treatment was more beneficial for linear growth than was the low micronutrient treatment. However, with some small differential effects, higher micronutrient concentrations were as effective as lower concentrations on cognitive performance. This trial was registered at clinicaltrials.gov as NCT00467909.

Effect of combining multiple micronutrients with iron supplementation on Hb response in children: systematic review of randomized controlled trials

OBJECTIVES

To study the effect of combining multiple (two or more) micronutrients with Fe supplementation on Hb response, when compared with placebo and with Fe supplementation, in children.

DATA SOURCES

Electronic databases, personal files, hand search of reviews, bibliographies of books, and abstracts and proceedings of international conferences.

REVIEW METHODS

Randomized controlled trials evaluating change in Hb levels with interventions that included Fe and multiple-micronutrient supplementation in comparison to placebo alone or Fe alone were analysed in two systematic reviews.

RESULTS

Twenty-five trials were included in the review comparing Fe and micronutrient supplementation with placebo. The pooled estimate (random effects model) for change in Hb with Fe and micronutrient supplementation (weighted mean difference) was 0.65 g/dl (95 % CI 0.50, 0.80, P < 0.001). Lower baseline Hb, lower height-for-age Z score, non-intake of 'other micronutrients' and malarial non-hyperendemic region were significant predictors of greater Hb response and heterogeneity. Thirteen trials were included in the review comparing Fe and micronutrient supplementation with Fe alone. The pooled estimate for change in Hb with Fe and micronutrient supplementation (weighted mean difference) was 0.14 g/dl (95 % CI 0.00, 0.28, P = 0.04). None of the variables were found to be significant predictors of Hb response.

CONCLUSIONS

Synthesized evidence indicates that addition of multiple micronutrients to Fe supplementation may only marginally improve Hb response compared with Fe supplementation alone. However, addition of 'other micronutrients' may have a negative effect. Routine addition of unselected multiple micronutrients to Fe therefore appears unjustified for nutritional anaemia control programmes.

A review and meta-analysis of the impact of intestinal worms on child growth and nutrition

More than a half of the world's population are infected with one or more species of intestinal worms of which the nematodes Ascaris lumbricoides, Trichuris trichiura and the hookworms are the most common and important in terms of child health. This paper: (1) introduces the main species of intestinal worms with particular attention to intestinal nematodes; (2) examines how such worms may affect child growth and nutrition; (3) reviews the biological and epidemiological factors that influence the effects that worms can have on the growth and nutrition of children; (4) considers the many factors that can affect the impact of treatment with anthelmintic drugs; (5) presents the results of a meta-analysis of studies of the effect of treating worm infections on child growth and nutrition; (6) discusses the results in terms of what is reasonable to expect that deworming alone can achieve; (7) describes some important characteristics of an ideal study of the effects of deworming; and (8) comments on the implications for programmes of recommendations concerning mass deworming.

Deworming drugs for treating soil-transmitted intestinal worms in children: effects on growth and school performance

BACKGROUND

In areas where intestinal worm infections occur, the World Health Organization recommends treating all school children at regular intervals with deworming drugs to improve growth and school performance. The evidence base for this policy needs to be established for countries to commit resources to implement these programmes.

OBJECTIVES

To summarize the effects of deworming drugs used to treat soil-transmitted intestinal worms (nematode geohelminths) on growth and school performance in children.

SEARCH STRATEGY

In May 2007, we searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (The Cochrane Library 2007, Issue 2), MEDLINE, EMBASE, LILACS, mRCT, and reference lists.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials (RCTs) comparing deworming drugs for geohelminth worms with placebo or no treatment in children aged 16 years or less, reporting on growth, nutritional status, school performance, or cognition tests.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the trials and evaluated methodological quality; one author extracted data, and another checked a sample. Continuous data were analysed using the weighted mean difference (WMD) with 95% confidence intervals (CI). The random-effects model (RE model) was used in the presence of statistically significant heterogeneity.

MAIN RESULTS

Thirty-four RCTs, including six cluster-RCTs, met the inclusion criteria. Four trials had adequate allocation concealment, and three cluster-RCTs failed to take design effects into account in their analysis. Weight increased after one dose of a deworming drug (WMD 0.34 kg, 95% CI 0.05 to 0.64, RE model; 2448 children, 9 trials); however, there was considerable heterogeneity between trials that was not explained by background intestinal worm infection or intensity. A meta-analysis of multiple dose trials reporting on outcomes within a year of starting treatment showed no significant difference in weight gain (1714 children, 6 trials); however, one cluster-RCT did show effects on weight at one year in a subgroup analysis. In the seven multiple dose trials with follow up beyond 12 months, only one showed a significant increase in weight. Six of seven trials reported clear data on cognitive tests and school performance: five reported no significant effects, and one showed some improvements in three out of 10 cognitive tests.

AUTHORS' CONCLUSIONS

Deworming drugs used in targeted community programmes may be effective in relation to weight gain in some circumstances but not in others. No effect on cognition or school performance has been demonstrated.

Effect of a 12-mo micronutrient intervention on learning and memory in well-nourished and marginally nourished school-aged children: 2 parallel, randomized, placebo-controlled studies in Australia and Indonesia

BACKGROUND

Little is known about the combined effect of micronutrients and essential fatty acids on cognitive function in school-aged children.

OBJECTIVE

We assessed the effect of micronutrients, long-chain n-3 fatty acids, or both on indicators of cognitive performance in well-nourished and marginally nourished school-aged children.

DESIGN

Two 2-by-2 factorial randomized controlled double-blind trials were performed home-based in Adelaide, South Australia, and at 6 primary schools in Jakarta, Indonesia. A total of 396 children (aged 6-10 y) in Australia and 384 children in Indonesia were randomly allocated to receive a drink with a micronutrient mix (iron, zinc, folate, and vitamins A, B-6, B-12, and C), with docosahexanoic acid (DHA, 88 mg/d) and eicosapentaenoic acid (EPA, 22 mg/d), or with both or placebo 6 d/wk for 12 mo. Biochemical indicators were determined at baseline and 12 mo. Cognitive performance was measured at baseline, 6 mo, and 12 mo.

RESULTS

The micronutrient treatment significantly improved plasma micronutrient concentrations in Australian and Indonesian children. DHA+EPA treatment increased plasma DHA and total plasma n-3 fatty acids in both countries. The micronutrient treatment resulted in significant increases in scores on tests representing verbal learning and memory in Australia (estimated effect size: 0.23; 95% CI: 0.01, 0.46). A similar effect was observed among Indonesian girls (estimated effect size: 0.32; 95% CI: -0.01, 0.64). No effects were found on tests measuring general intelligence or attention. No effects of DHA+EPA on the factors of cognitive tests were observed.

CONCLUSION

In well-nourished school-aged children, fortification with multiple micronutrients can result in improvements in verbal learning and memory.

WITHDRAWN: Anthelmintic drugs for treating worms in children: effects on growth and cognitive performance

BACKGROUND

In communities where helminth (worm) infections are common, they may contribute to poor nutritional status, anaemia, and impaired growth and learning in children. The World Health Organization, the World Bank and others recommend that children are routinely given deworming drugs in developing countries. This requires resources to deliver.

OBJECTIVES

To summarise the effects of anthelmintic drug treatment in children in relation to their growth and cognitive performance.

SEARCH STRATEGY

We searched the Cochrane Infectious Diseases Group Specialized Register (August 2004), CENTRAL) The Cochrane Library Issue 3, 2004), MEDLINE (1966 to August 2004), EMBASE (1980 to August 2004), and LILACS (August 2004). We contacted experts in the field.

SELECTION CRITERIA

Randomised and quasi-randomised trials of drug treatment compared with placebo or no drug treatment for intestinal helminths in children.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed and data were extracted independently by two reviewers. Study authors were contacted for additional information.

MAIN RESULTS

Thirty trials involving more than 1500 children were included. There was potential for bias from inadequate concealment of allocation. Studies varied in relation to target groups, drugs administered and treatment regimens. Compared to placebo or no drug treatment, drug treatment for helminths was associated with some positive effects on change in weight, height and skinfold thickness. However there was significant heterogeneity between the results of the trials. There were some positive effects on mean weight change in the trials reporting this outcome; after a single dose (any anthelminth) the pooled estimate was 0.17 kg, (95% CI 0.10 to 0.25; fixed effects model assumed); and 0.38 kg (95% CI 0.00 to 0.77; random effects model assumed). Results from trials giving multiple doses showed mean weight change under one year of follow up of 0.10 kg (95% CI 0.04 to 0.17; fixed effects assumed); or 0.15 (95% CI 0.00 to 0.30; random effects assumed). At more than one year of follow up, mean weight change was 0.12 kg (95% CI -0.02 to 0.26; fixed effects assumed) and 0.43 (95% CI -0.61 to 1.47; random effects model assumed). Results from studies of cognitive performance were mixed and inconclusive.

AUTHORS' CONCLUSIONS

There is some limited evidence that routine treatment of children in areas where helminths are common has small effects on weight gain, but this is not consistent between trials. There is insufficient evidence to know whether this intervention improves cognitive performance. Our interpretation of these results is that the current public health programme investments in this intervention, based on the expectation that there will be an improvement in growth and learning, are not based on consistent or reliable evidence.

Single Low-Dose Mebendazole Administered Quarterly for Ascaris Treatment

BACKGROUND

Intestinal parasites are difficult to eradicate in tropical climates where poor sanitation exists. In addition, pharmaceutical stability is poor making traditional three day dosing for the treatment of A. lumricoides challenging.

METHODS

Single 100 mg doses of mebendazole were administered to persons living along Amazon tributaries in Northeastern Peru. Directly-observed treatment was repeated at 3-month intervals over a 2-year period in a single treatment village. Treatment was repeated at 12-month intervals in the remaining (control) villages. Treatment was accompanied by a regimen of multivitamins with iron to be taken daily for 14 days after each treatment. Subjects were screened for ova and parasites prior to treatment and at 1-year intervals. In addition to A. lumbricoides, other parasites found on screening were recorded.

RESULTS

Treatment resulted in a 92.5% cure rate for A. lumbricoides at the 2-year assessment. Growth and development assessments demonstrated fewer individuals below the 3 percentile for age-adjusted measurements when treated quarterly.

CONCLUSIONS

Based on these limited data, single low-dose mebendazole administered quarterly appears to have a positive effect on the health of isolated village populations in the Amazon River basin.

Effect of iron supplementation on haemoglobin response in children: systematic review of randomised controlled trials

OBJECTIVE

To evaluate the effect of iron supplementation on haemoglobin (Hb) in children through a systematic review of randomised controlled trials.

MATERIALS AND METHODS

Electronic databases, personal files, hand search of reviews, bibliographies of books, and abstracts and proceedings of international conferences were reviewed. Randomised controlled trials evaluating change in Hb levels with interventions that included oral or parenteral iron supplementation or iron-fortified formula milk or cereals were analysed.

RESULTS

A total of 55 trials (56 cohorts) provided relevant information. Publication bias was evident (P < 0.001). The pooled estimate (random-effects model) for change in Hb with iron supplementation (weighted mean difference) was 0.74 g/dL (95% CI, 0.61-0.87; P < 0.001; P < 0.001 for heterogeneity). Lower baseline Hb level, oral medicinal iron supplementation, and malarial nonhyperendemic region were significant predictors of greater Hb response and heterogeneity. Projections suggested that, on average, between 37.9% and 62.3% of baseline anaemia (Hb <11 g/dL) was responsive to iron supplementation among children under 6 years of age; the corresponding range for malarial hyperendemic regions was 5.8% to 31.8%.

CONCLUSIONS

This systematic review indicates that iron supplementation increases Hb levels in children significantly but modestly. The increase is greater in subjects who are anaemic at the start of the trial and lower in malarial hyperendemic areas and in those consuming iron-fortified food. The projected reductions in prevalence of anaemia with iron supplementation alone highlight the need for additional area-specific interventions, particularly in malaria-prone regions.

Implications of the prevalence of stunting, overweight and obesity amongst South African primary school children: a possible nutritional transition?

OBJECTIVE

To investigate the relationship between stunting and levels of overweight/obesity among South African school children, using two definitions of overweight and obesity, based on the WHO and International Obesity Task Force (IOTF) criteria.

DESIGN

Cross-sectional descriptive analysis of the nutritional status of primary school children, using primary data from a rural community-based study undertaken in 1995 and secondary data from the South African National Primary Schools (SANPS) survey conducted in 1994. Stunting was measured according to the WHO definition of -2 Z scores height-for-age. Two sets of criteria were used to measure overweight and obesity-the WHO/NCHS standard based on the 85th and 95th centiles and the IOTF criteria.

SETTING

The primary data source was from a rural KwaZulu-Natal community based survey. The secondary data source SANPS consisted of data at National and Provincial level; for this study only data from the province of KwaZulu-Natal was considered.

SUBJECTS

Primary school children aged between 8 and 11 y of age; 802 from the primary data source and 24 391 from the secondary source.

RESULTS

Moderate stunting ranged from 2.9 to 40.2%, and mild stunting ranged from 31.4 to 75%. The prevalence of overweight ranged from 0.4 to 13.3% (WHO criteria) and from 0.4 to 11.9% using the IOTF criteria; while obesity ranged from 0.1 to 3.7% (WHO) and from 0.1 to 1.5% (IOTF criteria). The prevalence of overweight and obesity was observed to be higher using the WHO definition than that of IOTF (0.05<P<0.10). However, good kappa coefficient (kappa) levels of agreement were observed between the WHO and IOTF definitions of overweight and obesity (kappa>0.55, in all cases). The levels of agreement in all cases were less for obesity than overweight (both ranged from 0.55 to 1.0). Females were observed to have higher kappa levels than their male counterparts; they also had higher prevalence levels of overweight and obesity across age and geographical group. Uniformly high levels of both mild and moderate stunting were observed both nationally and provincially. However, no excess relative risk of being overweight if stunted was observed in this study (P>0.05).

CONCLUSIONS

Caution must be applied when using either definition for obesity. However, very high levels of agreement occur for overweight. There is no obvious relationship between overweight and stunting in this study, but high levels of mild stunting were observed. Regular clinical and epidemiological monitoring of nutritional status needs to be undertaken in South Africa to examine possible future trends of overweight/obesity and their relationship with stunting, and for comparisons with global trends.