Lower Height-for-age Z-scores Research Articles

Is detection of enteropathogens and human or animal faecal markers in the environment associated with subsequent child enteric infections and growth: an individual participant data meta-analysis

Quantifying contributions of environmental faecal contamination to child diarrhoea and growth faltering can illuminate causal mechanisms behind modest health benefits in recent water, sanitation, and hygiene (WASH) trials. We aimed to assess associations between environmental detection of enteropathogens and human or animal microbial source tracking markers (MSTM) and subsequent child health outcomes. In this individual participant data meta-analysis we searched we searched PubMed, Embase, CAB Direct Global Health, Agricultural and Environmental Science Database, Web of Science, and Scopus for WASH intervention studies with a prospective design and concurrent control that measured enteropathogens or MSTM in environmental samples, or both, and subsequently measured enteric infections, diarrhoea, or height-for-age Z-scores (HAZ) in children younger than 5 years. We excluded studies that only measured faecal indicator bacteria. The initial search was done on Jan 19, 2021, and updated on March 22, 2023. One reviewer (AM) screened abstracts, and two independent reviewers (AM and RT) examined the full texts of short-listed articles. All included studies include at least one author that also contributed as an author to the present Article. Our primary outcomes were the 7-day prevalence of caregiver-reported diarrhoea and HAZ in children. For specific enteropathogens in the environment, primary outcomes also included subsequent child infection with the same pathogen ascertained by stool testing. We estimated associations using covariate-adjusted regressions and pooled estimates across studies. Data from nine published reports from five interventions studies, which included 8603 children (4302 girls and 4301 boys), were included in the meta-analysis. Environmental pathogen detection was associated with increased infection prevalence with the same pathogen and lower HAZ (ΔHAZ -0·09 [95% CI -0·17 to -0·01]) but not diarrhoea (prevalence ratio 1·22 [95% CI 0·95 to 1·58]), except during wet seasons. Detection of MSTM was not associated with diarrhoea (no pooled estimate) or HAZ (ΔHAZ -0·01 [-0·13 to 0·11] for human markers and ΔHAZ -0·02 [-0·24 to 0·21] for animal markers). Soil, children's hands, and stored drinking water were major transmission pathways. Our findings support a causal chain from pathogens in the environment to infection to growth faltering, indicating that the lack of WASH intervention effects on child growth might stem from insufficient reductions in environmental pathogen prevalence. Studies measuring enteropathogens in the environment should subsequently measure the same pathogens in stool to further examine theories of change between WASH, faecal contamination, and health. Given that environmental pathogen detection was predictive of infection, programmes targeting specific pathogens (eg, vaccinations and elimination efforts) can environmentally monitor the pathogens of interest for population-level surveillance instead of collecting individual biospecimens. The Bill & Melinda Gates Foundation and the UK Foreign and Commonwealth Development Office.

Biomass smoke exposure and somatic growth among children: The RESPIRE and CRECER prospective cohort studies in rural Guatemala

BackgroundCooking-related biomass smoke is a major source of household air pollution (HAP) and an important health hazard. Prior studies identified associations between HAP exposure and childhood stunting; less is known for underweight and wasting. Few studies had personal HAP measurements. Methods557 households in rural Guatemala were enrolled in the CRECER study, the follow-up study of the RESPIRE randomized intervention trial. They were assigned to three groups that received chimney stoves at different ages of the study children. Multiple personal carbon monoxide (CO) exposure measurements were used as proxies for HAP exposures. Children’s heights and weights were measured from 24 to 60 months of age. Height-for-age z-score (HAZ), weight-for-age z-score (WAZ), and weight-for-height z-score (WHZ) were calculated based on the World Health Organization’s Multicentre Growth Reference Study. HAZ, WAZ, and WHZ below −2 were classified as stunting, underweight, and wasting, respectively. Generalized linear models and mixed effects models were applied. Results541 children had valid anthropometric data, among whom 488 (90.2 %) were stunted, 192 (35.5 %) were underweight, and 2 (0.3 %) were wasted. A 1 ppm higher average CO exposure was associated with a 0.21 lower HAZ (95 % CI: 0.17–0.25), a 0.13 lower WAZ (95 % CI: 0.10–0.17) and a 0.06 lower WHZ (95 % CI: 0.02–0.10).The associations for HAZ were stronger among boys (coefficient = −0.29, 95 % CI: −0.35 – −0.22) than among girls (coefficient = −0.15, 95 % CI: −0.20 – −0.10). A 1 ppm-year higher cumulative CO exposure was associated with a higher risk of moderate stunting among boys (OR = 1.27, 95 % CI: 1.05-1.59), but not among girls. DiscussionIn this rural Guatemalan population, higher HAP exposure was associated with lower HAZ and WAZ. The associations between HAP and HAZ/stunting were stronger among boys. Reducing HAP might benefit childhood somatic growth in rural populations of low-income countries.

Predictors of height in Romanian infants 6-23 months old: findings from a national representative sample.

The research explored the association between infants' height and various demographic factors in Romania, a country where such critical information has been lacking. This study was conducted on a nationally representative sample and used a family physicians database to determine a sample of 1532 children (713 girls and 819 boys) 6-23 months of age (M=14.26; SD=5.15). Infants' height-for-age z-scores (HAZ) were calculated using the World Health Organization's computing algorithm. A multiple regression analysis was conducted to investigate whether certain risk factors, such as infant mother's age, location, marital status, socioeconomic status (SES), as well as infant's term status at birth, age, anemia, minimum dietary diversity (MDD) and birth order, could significantly predict the HAZ. The study identified several significant predictors of height. Specifically, lower HAZ was associated with rural living, preterm birth, age 18-23 months, unmarried mothers, anemia, lack of MDD and being third or later born in the family. In contrast, higher HAZ was associated with medium or high maternal SES and older maternal age. The study underscores the importance of addressing these significant risk factors through distinct interventions to improve height outcomes in at-risk Romanian populations.

Evaluation of growth status of children with non-syndromic oral clefts.

To assess the growth status of children with non-syndromic oral clefts (NSOC) and explore potential influencing factors. The data of NSOC children aged ≤5 years hospitalized between December 2018 and June 2020 were retrieved and evaluated, including their height, weight, NSOC subtypes and demographic characteristics before reparative surgeries. The growth status of the children was assessed using height-for-age Z-score (HAZ), weight-for-age Z-score (WAZ) and weight-for-height Z-score (WHZ). In total, 504 NSOC children (271 females & 233 males) were included. The proportion of stunting (HAZ <-2), underweight (WAZ <-2) and wasting (WHZ <-2) was 4.96%, 5.16% and 3.97%, respectively. In addition, we observed that HAZ and WAZ decreased with increasing age (both p < 0.01). Moreover, non-syndromic cleft palate only (NSCP) and non-syndromic cleft lip and palate (NSCLP) were associated with lower HAZ and WAZ compared with non-syndromic cleft lip only (NSCL) (all p < 0.01), while NSCLP was associated with a lower WHZ compared with NSCL (p < 0.01). The growth retardation and low weight rate of NSOC children under 5 years old were higher than the national average level and differed by the age of NSOC children and disease subtypes. Further improvements are warranted to promote the growth status of the NSOC-affected children.

52 Underweight in the first 2 years of life and growth in later childhood

Abstract Background Underweight occurs when caloric intake is insufficient to maintain growth. While it has long been assumed that underweight in the first 2 years of life is associated with lower growth potential in later childhood, longer term growth outcomes in high income countries are unclear. Objectives The primary objective was to evaluate the relationship between underweight in the first 2 years of life and body mass index z-score (zBMI) in later childhood. Secondly, we examined the relationship between underweight in the first 2 years of life and weight-for-age z-score (WAZ) and height-for-age z-score (HAZ) in later childhood, and how sex and the zBMI growth trajectory in the first 2 years of life modify these associations. Design/Methods This was a prospective cohort study conducted through The Applied Research Group for Kids (TARGetKids!) practice-based research network. Healthy children 0-10 years of age were included. The primary exposure was underweight in the first 2 years of life using zBMI &amp;lt;-2 as per the World Health Organization (WHO). The primary outcome was zBMI, and secondary outcomes were WAZ and HAZ between 2 and 10 years of age. Linear mixed effects models were used for the primary and secondary analysis to take into account multiple growth measures over time. Interaction terms for sex, and the zBMI growth trajectory in the first 2 years of life were used to explore effect modification. Results Among the 5,803 children included in the primary analysis, the mean age was 4.07 months, and 52.2% were male at baseline. In adjusted models, underweight in the first 2 years of life was associated with lower zBMI, lower WAZ, and higher odds of underweight at 2, 5, and 10 years of age (p &amp;lt;0.0001). Underweight in the first 2 years was associated with a lower HAZ at 2 years of age (p&amp;lt;0.0001), but not 5 (p=0.08), or 10 years of age (p=0.8). Females with underweight had lower zBMI and WAZ at 5 and 10 years of age, and lower HAZ at 10 years of age compared to males with underweight (p&amp;lt;0.05). Children with underweight and lower growth trajectory in the first 2 years had lower zBMI, WAZ, HAZ, and higher odds of underweight at 2, 5, and 10 years of age compared to children who did not have underweight (p&amp;lt;0.05). Children with underweight and high growth trajectory in the first 2 years had similar zBMI, WAZ, higher HAZ and lower odds of overweight at 10 years of age (p&amp;lt;0.05), compared to children who did not have underweight. Conclusion Underweight in the first 2 years of life was associated with lower growth in later childhood. These relationships were amplified for females and children with underweight who had low growth trajectory in the first 2 years of life and were attenuated among children with underweight who had high growth trajectory in the first 2 years of life.

Growth and the pubertal growth spurt in South African adolescents living with perinatally-acquired HIV infection.

The majority children living with HIV infection now survive into adulthood because of effective antiretroviral therapy (ART), but few data exist on their growth during adolescent years. This study investigated growth patterns and evaluated factors associated with suboptimal growth in adolescents with perinatally-acquired HIV infection. This retrospective cohort study included HIV-infected adolescents, aged 13 to 18 years, with at least 5 years of ART follow-up at a large HIV clinic in the Gauteng Province, South Africa. Weight-for-age Z-scores (WAZ), height-for-age Z-scores (HAZ) and body mass index (BMI)-for-age Z-scores were calculated using World Health Organization (WHO) growth standards. Growth velocity graphs were generated utilising the mean height change calculated at 6-monthly intervals, using all available data after ART initiation, to calculate the annual change. Other collected data included WHO HIV disease staging, CD4%, HIV viral loads (VLs), ART regimens and tuberculosis co-infection. Included were 288 children with a median age of 6.5 years (IQR 4.2;8.6 years) at ART initiation, and 51.7% were male. At baseline the majority of children had severe disease (92% WHO stages 3&4) and were started on non-nucleoside reverse transcriptase inhibitor-based regimens (79.2%). The median CD4% was 13.5% (IQR 7.9;18.9) and median HIV viral load log 5.0 (IQR 4.4;5.5). Baseline stunting (HAZ <-2) was prevalent (55.9%), with a median HAZ of -2.2 (IQR -3.1;-1.3). The median WAZ was -1.5 (IQR -2.5;-0.8), with 29.2% being underweight-for-age (WAZ <-2). The peak height velocity (PHV) in adolescents with baseline stage 3 disease was higher than for those with stage 4 disease. Being older at ART start (p<0.001) and baseline stunting (p<0.001) were associated with poorer growth, resulting in a lower HAZ at study exit, with boys more significantly affected than girls (p<0.001). Suboptimal growth in adolescents with perinatally-acquired HIV infection is a significant health concern, especially in children who started ART later in terms of age and who had baseline stunting and is more pronounced in boys than in girls.

Growth patterns by sex and age among under-5 children from 87 low-income and middle-income countries

IntroductionAlthough boys tend to be more affected by linear growth faltering than girls, little is known about sex differences across distinct age groups. We aimed to compare sex differences in...

Maternal experience of domestic violence before and during pregnancy and children's linear growth at 15 years: Findings from MINIMat trial in rural Bangladesh.

Literature concerning negative impacts of domestic violence (DV) against women on their children's health is growing; however, little is known about the long‐term effect of maternal exposure to DV before and/or during pregnancy on their children's growth. Using data from the MINIMat cohort, we have evaluated the association between maternal lifetime experience of DV, measured in late pregnancy, with their children's linear growth at 15 years (n = 2240) in rural Bangladesh. A modified version of conflict tactic scale was used to record the maternal experience of physical, sexual, emotional DV and controlling behaviour. Children's height was measured by trained nurses during their clinical visits at 15‐year follow‐up. Compared to the women with no experience of DV, children of women with experience of any physical, sexual or emotional DV before and/or during pregnancy had the significantly lower height for age Z‐scores (HAZs) at the age of 15. No significant association between maternal experience of controlling behaviour and their children's linear growth was observed in terms of HAZ. Results from this study suggest that maternal experience of DV before and/or during pregnancy might be associated with impaired long‐term linear growth within their children.

Irrigation, drinking water quality, and child nutritional status in northern Ethiopia

Abstract In this paper, we investigate the relationship between household drinking water quality and irrigation and child nutrition using primary household survey data and microbiological water sample testings in two rural districts of Ethiopia. Anthropometric measures such as height-for-age z-scores (HAZ), weight-for-age z-scores (WAZ), and weight-for-height z-scores (WHZ) were used to measure stunting, underweight, and wasting, respectively. Our survey results show that 41% of the children are stunted, 26% underweight, and 8% wasted. More than 58% of household's stored drinking water samples were also contaminated with Escherichia coli bacteria. The multivariate regression results suggest that irrigation farming and on-premises water sources are significantly associated with lower HAZ, while uncontaminated household stored drinking water quality is correlated with higher WAZ. The results also reveal that dietary diversity score and the number of antenatal care visits by the primary caretaker are statistically significant predictors of child nutritional status. These findings, however, cast doubt on the hypothesis that irrigated agriculture exclusively has a positive effect on child nutrition outcomes.

Environmental exposure to metal mixtures and linear growth in healthy Ugandan children.

Stunting is an indicator of poor linear growth in children and is an important public health problem in many countries. Both nutritional deficits and toxic exposures can contribute to lower height-for-age Z-score (HAZ) and stunting (HAZ < -2). In a community-based cross-sectional sample of 97 healthy children ages 6-59 months in Kampala, Uganda, we examined whether exposure to Pb, As, Cd, Se, or Zn were associated with HAZ individually or as a mixture. Blood samples were analyzed for a mixture of metals, which represent both toxins and essential nutrients. The association between HAZ and metal exposure was tested using multivariable linear regression and Weighted Quantile Sum (WQS) regression, which uses mixtures of correlated exposures as a predictor. There were 22 stunted children in the sample, mean HAZ was -0.74 (SD = 1.84). Linear regression showed that Pb (β = -0.80, p = 0.021) and Se (β = 1.92, p = 0.005) were significantly associated with HAZ. The WQS models separated toxic elements with a presumed negative effect on HAZ (Pb, As, Cd) from essential nutrients with presumed positive effect on HAZ (Se and Zn). The toxic mixture was significantly associated with lower HAZ (β = -0.47, p = 0.03), with 62% of the effect from Pb. The nutrient WQS index did not reach statistical significance (β = -0.47, p = 0.16). Higher blood lead and lower blood selenium level were both associated with lower HAZ. The significant associations by linear regression were reinforced by the WQS models, although not all associations reached statistical significance. These findings suggest that healthy children in this neighborhood of Kampala, Uganda, who have a high burden of toxic exposures, may experience detrimental health effects associated with these exposures in an environment where exposure sources are not well characterized.

Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.

Objective:The aim of this study was to describe growth during puberty in young people with vertically acquired HIV.Design:Pooled data from 12 paediatric HIV cohorts in Europe and Thailand.Methods:One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1–10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters.Results:At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and −1.2 (IQR: −2.3 to −0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20–0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21–1.78) years later in those starting with HAZ less than −3 compared with HAZ at least −1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than −1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least −1, there was no association with age. Girls and boys who initiated ART with HAZ at least −1 maintained a similar height to the WHO reference mean.Conclusion:Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least −1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age.

Sex effect on growth faltering in an indigenous ethnic minority population of infants in Israel.

We examined sex effects on growth faltering in an indigenous population of Bedouin Arab infants born in Israel, an economically developed country. Retrospective cohort study. Height-for-age Z-score (HAZ) at age 6, 12, 18 and 24months was calculated for full-term, normal-birth-weight Bedouin infants born during years 2000-2009 and attending maternal and child health (MCH) clinics. Multivariate linear regression analysis (MLRA) was used to calculate the association between sex and HAZ, controlling for year of birth, birth weight (BW) and residence by type of settlement (established settlement (ES); non-established settlement (NES)). Bedouin are an indigenous poor community of semi-nomadic Arabs, with the highest infant mortality rate in Israel. Fifty per cent of Bedouin infants live in NES with inadequate access to running water, electricity, and rubbish and sewage disposal. All Bedouin receive free well-baby care in community-based MCH clinics. Full-term, normal Bedouin infants (n5426) born during 2000-2009 and attending computerized MCH clinics who had growth measurements at age 6, 12, 18 and 24months. At all ages, girls had significantly higher mean HAZ than boys (P < 0·05). Increasing birth year, residence in ES and increasing BW were positively associated with HAZ (P < 0·05) at all ages. In MLRA controlling for birth year, BW and type of settlement, sex still had a significant effect, with lower HAZ among boys at 6, 12, 18 and 24months of age (P < 0·001 at all ages). Our results indicated that sex effects on growth faltering can occur in an indigenous population with low socio-economic status within an economically developed country.

Associations between birth registration and early child growth and development: evidence from 31 low- and middle-income countries

BackgroundLack of legal identification documents can impose major challenges for children in low- and middle-income countries (LMICs). The aim of this study was to investigate the association between not having a birth certificate and young children’s physical growth and developmental outcomes in LMICs.MethodsWe combined nationally representative data from the Multiple Indicator Cluster Surveys in 31 LMICs. For our measure of birth registration, primary caregivers reported on whether the child had a birth certificate. Early child outcome measures focused on height-for-age z-scores (HAZ), weight-for-age z-scores (WAZ), weight-for-height z-scores (WHZ), and standardized scores of the Early Childhood Development Index (ECDI) for a subsample of children aged 36–59 months. We used linear regression models with country fixed effects to estimate the relationship between birth registration and child outcomes. In fully adjusted models, we controlled for a variety of child, caregiver, household, and access to child services covariates, including cluster-level fixed effects.ResultsIn the total sample, 34.7% of children aged 0–59 months did not possess a birth certificate. After controlling for covariates, not owning a birth certificate was associated with lower HAZ (β = − 0.18; 95% CI: -0.23, − 0.14), WAZ (β = − 0.10, 95% CI: -0.13, − 0.07), and ECDI z-scores (β = − 0.10; 95% CI: -0.13, − 0.07) among children aged 36–59 months.ConclusionOur findings document links between birth registration and children’s early growth and development outcomes. Efforts to increase birth registration may be promising for promoting early childhood development in LMICs.

Effect of low-dose versus higher-dose antenatal iron supplementation on child health outcomes at 36 months of age in Viet Nam: longitudinal follow-up of a cluster randomised controlled trial

IntroductionIntermittent iron-folic acid supplementation (IFA) is currently recommended for pregnant women in populations where anaemia prevalence among pregnant women is <20% or if daily iron is not acceptable. The effect...

The effect of maternal and child factors on stunting, wasting and underweight among preschool children in Northern Ghana

BackgroundUndernutrition among preschool children in Northern region is the highest in Ghana. However, there is scarcity of data on the factors that determine undernutrition in these children. This study investigated the effect of maternal and child factors on undernutrition among preschool children in Northern Ghana.MethodsThis study was a community based analytical cross-sectional survey on a sample of 425 mother- child pairs drawn from 25 clusters. A semi- structured questionnaire was used to collect data on maternal and child socio-demographic characteristics, feeding practices and anthropometry. Anthropometric indices of Height-for-age Z-scores (HAZ), Weight-for-height Z-scores (WHZ) and Weight-for – age Z-scores (WAZ) were used to classify child stunting, wasting and underweight respectively. Bivariate and multivariate analyses were performed to determine associations between explanatory variables and undernutrition.ResultsThe prevalence of stunting, wasting and underweight were 28.2, 9.9 and 19.3% respectively. Multiple logistic regression analysis showed that, the odds of stunting was higher among male children [AOR = 1.99; 95% CI (1.26–3.13); p = 0.003], children of mothers less than 150 cm in height [AOR = 3.87; 95% CI (1.34–11.20); p = 0.01], mothers 155–159 cm tall [AOR = 2.21; 95% CI (1.34–3.66); p = 0.002], and older children aged 12–23 months [AOR 9.81; 95% CI (2.85–33.76); p < 0.001]. Wasting was significantly higher among male children [AOR = 2.40; 95% CI (1.189–4.844); p = 0.015], consumption of less than four food groups [AOR = 3.733; 95% CI (1.889–7.376); p < 0.001] and among children of underweight mothers [AOR = 3.897; 95% CI (1.404–10.820); p = 0.009]. Male children [AOR = 2.685; 95% CI (1.205–5.98); p = 0.016] and having low birth weight [AOR = 3.778; 95% CI (1.440–9.911); p < 0.001] were associated with higher odds of underweight in children.ConclusionMaternal height associated negatively with stunting but not wasting. Factors that affect low height –for-age z-score (HAZ) may not necessarily be the same as stunting. Infant and child feeding practices as measured by dietary diversity score associated positively with weight-for-height Z-scores than length-for-age Z-scores of young children. Surprisingly, consumption of some specific food groups including, animal source foods, legumes, staples and eggs were associated with lower HAZ but with increased likelihood of higher WHZ among children 6–59 months.

Anemia and growth retardation associated with Schistosoma haematobium infection in Mali: a possible subtle impact of a neglected tropical disease.

The aim of this cross-sectional study was to investigate a possible association of Schistosoma haematobium with child growth development and describe a plausible schistosomiasis-related anemia in children and adults in a highly schistosomiasis endemic area of Mali. Urine, feces and blood samples from 399 participants of both sexes (2-40 years of age) were analyzed and supplemented by anthropometric measurements. S. haematobium prevalence was 79.8%, S. mansoni 13.2% and Plasmodium falciparum 80.2%. S. haematobium infection intensity as five categories was significantly associated with anemia; i.e., odds of having anemia in the highest and the next highest category was 3.25 (95% CL 1.61-6.55; p<0.01) and 2.45 (95% CL 1.28-4.70; p<0.01), respectively, of that in the three lower categories combined after adjusting for age group and gender and the interaction between the two factors. Anemia was most pronounced in the 2-5 year olds males (55.5%, n=98). P. falciparum infection was not significantly associated with anemia. Stunting (body mass index [BMI] for age z-score<-2.00) was observed in 2.6% (2/78) of the 2-5 years olds and in 7.7% (14/182) in the 6-19 years age group. Lower BMI-z-scores (as continuous variable) were associated with anemia (p<0.05) while high intensity of S. haematobium infection was not significant when adjusting for age group and anemia. Participants with malaria infection had lower z-scores (as continuous variables) of weight and height for age. Lower height for age z-scores were also associated with anemia. S. haematobium infection is likely to impact on child growth and possibly also anemia in all age groups and advocates for inclusion of whole populations into future control programes.

Aflatoxin exposure among young children in urban low-income areas of Nairobi and association with child growth

Populations in tropical and subtropical developing countries are exposed to largely uncontrolled levels of aflatoxins through food. These countries (especially in Africa and Asia) also present a high prevalence of stunting. Studies have reported an association between aflatoxin exposure and growth impairment in children but there is not yet conclusive evidence that aflatoxins are a significant cause of stunting in children, thus further research is warranted. In this cross-sectional study, 204 low-income households were randomly selected in two low-income areas of Nairobi, Kenya. Korogocho is a higher population density area and Dagoretti a lower population density area. We asked questions about household demographics and a 24-hour dietary recall was conducted in children aged 1–3 years. Child anthropometric measurements were also conducted. Height-for-age Z-scores (HAZ), weight-for-age Z-scores (WAZ) and weight-for-height Z-scores (WHZ) were calculated for each child using World Health Organization (WHO) growth standards reference data. Samples of foods were taken from the household or from the retailer for analysis using competitive enzyme-linked immunosorbent assay (ELISA). Laboratory results for aflatoxin levels in the food samples collected were used to calculate the daily aflatoxin intake, according to the results from the dietary assessment. The study found 41% of children sampled had stunted growth. Boys were more stunted than girls (p=0.057) and Korogocho had more stunted children than Dagoretti (p=0.041). In all, 98% of food samples collected tested positive for aflatoxin and there was an average exposure to aflatoxins of 21.3 ng/kg bodyweight per day. Exposure to aflatoxin M1 (AFM1), location and sex were significantly associated with HAZ, with boys and children from Korogocho having lower HAZ, and AFM1 was negatively associated with HAZ (p=0.047), indicating that AFM1 was associated with stunting. There was no association between total aflatoxins (aflatoxin B [AFB] and aflatoxin G [AFG]) and HAZ, WAZ and WHZ. The study showed a high prevalence of malnutrition, especially stunting, in two low-income urban sites, and this was most pronounced in the high-density area. The reported association between AFM1 and stunted children indicates that more research is needed on the health impacts of this aflatoxin in growing children. Keywords: stunting, aflatoxin M1, contamination, exposure, mycotoxin, ELISA, aflatoxins, mycotoxins, aflatoxin B1

Civil War, Crop Failure, and Child Stunting in Rwanda

Economic shocks at birth have lasting effects on children's health several years after the shock. The authors calculate height for age z-scores for children under age five using data from a Rwandan nationally representative household survey conducted in 1992. They exploit district and time variation in crop failure and civil conflict to measure the impact of exogenous shocks that children experience at birth on their height several years later. They find that boys and girls born after the shock in regions experiencing civil conflict are both negatively affected with height for age z-scores 0.30 and 0.72 standard deviations lower, respectively. Conversely, only girls are negatively affected by crop failure, with these girls exhibiting 0.41 standard deviation lower height for age z-scores and the impact is worse for girls in poor households. Results are robust to using sibling difference estimators, household level production, and rainfall shocks as alternative measures of crop failure.

Malnutrition in China's rural boarding schools: the case of primary schools in Shaanxi Province

The main goal of this paper is to document the nature of boarding schools and empirically analyse the difference in nutrition intake and malnutrition status between boarding and non-boarding students in western rural China. By using two data sets on boarding schools and boarding students in Shaanxi Province, a representative province in western rural China, this paper finds that dormitory and student canteen facilities in boarding schools are under-equipped and services are of poor quality, far below that needed for student development. Poor services in boarding schools and inadequate nutrition intake may be an important cause of low student height-for-age Z-scores (HAZ), as students eating at school have a much lower HAZ on average than that of non-boarding students. Furthermore, girls and students with more siblings have relatively lower HAZ, while the higher the number of parents a student has and the more educated they are exerts a positive influence on child nutritional status. Finally, our analysis implies that the effective way to decrease the inequality of health, malnutrition and human capital between urban and rural areas in the long run is to improve the facilities and services of boarding schools in rural China.

Growth status and academic performance in Brazilian school age children: growth retardation impairs mathematical, but not reading and spelling abilities

To assess the effect of child growth status on academic achievement and the association between child growth and academic standing. The heights of 722 middle-school children were measured using standard procedures and height-for-age z (HAZ) scores were calculated based on an international reference. Academic performance was assessed by an adaptation of the Wide Range Achievement Test (WRAT3) composed of Reading, Arithmetic and Spelling. Children in the group with higher HAZ scores performed better than children in the group with lower HAZ scores only on the Arithmetic subtest. This finding was confirmed by a multiple regression model analysis of the data. In addition, only performance on the Arithmetic subtest was positively associated with HAZ. These results indicate that growth retardation impacts specifically on the development of arithmetic (numeracy) skills and are consistent with a three-fold model of life course influences on health including latency, cumulative and pathway effects.