Mycotoxin Exposure, Child Stunting and Birth Outcomes: Future Directions for the SHINE Trial

Clockwise from left: Loveness Nyanga (Faculty University of Zimbabwe), Nabila Ismail (UB PharmD Student), Charles Maponga (UB Faculty), Nadia Koyratty (UB EEH PhD Student), Laura Smith (UB faculty)

Clockwise from left: Loveness Nyanga (Faculty University of Zimbabwe), Nabila Ismail (UB PharmD Student), Charles Maponga (UB Faculty), Nadia Koyratty (UB EEH PhD Student), Laura Smith (UB faculty)

Low height-for-age, or stunting, is a major contributor to childhood mortality globally and is often used as a marker of malnutrition in children. Stunting is most likely to occur in the first 24 months of life, and is characterized by a child having a length-for-age z-score (LAZ), or height-for-age z-score (HAZ), below two standard deviations. Stunted children are more likely to have cognitive delays, face higher rates of mortality, and can have decreased economic productivity in adulthood. Compounding on this, children are at increased risk of stunting if their parents were stunted as children themselves, establishing an intergenerational cycle of decreased economic productivity and increased mortality. Rural regions in Sub-Saharan Africa and South Asia especially suffer from a high prevalence of stunting in children under the age of 5. 

SHINE Trial

To examine the effects of malnutrition and poor water, sanitation, and hygiene (WASH), thought to be two of the largest contributors to child stunting, on child stunting in the rural districts of Chirumanzu and Shurugwi in Zimbabwe, the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial was conducted from November, 2012 until August, 2017. SHINE was a cluster-randomized, community-based, 2x2 factorial trial of pregnant mothers permanently living in one of the clustered catchment areas, covered by between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Clusters were randomized (1:1:1:1) into one of four experimental groups; standard of care (control), an improved infant and young child feeding (IYCF) intervention, an improved WASH intervention, and a combined improved IYCF and WASH intervention. Participating mothers and children were then followed up through birth and the 18 months following birth. A variety of outcomes were measured throughout the study; however, the primary outcomes were child stunting and anemia, in children born to HIV-negative mothers, at the age of 18 months.

Preliminary results for the SHINE trial were published in January, 2019 in the Lancet. Briefly, researchers found a 0.16 (95% CI 0.08–0.23) greater mean LAZ and 2.03 g/L (1.28–2.79) greater mean hemoglobin concentration in IYCF intervention groups when compared to groups who did not receive the IYCF intervention. Comparatively, these effects reduced the number of stunted children from 620 (35%) in the non-IYCF groups to 514 (27%) in the IYCF groups, and the number of children with anemia from 245 (13.9%) in the non-IYCF groups to 193 (10.5%) in the IYCF groups. There was no effect on either anemia or stunting from the WASH intervention, and researchers concluded that combination WASH/IYCF interventions were unlikely reduce stunting and anemia in children more than IYCF interventions alone. Dr. Laura Smith is a co-investigator on this trial. Funding was provided by the Bill & Melinda Gates Foundation, the UK Department for International Development, the Wellcome Trust, the Swiss Development Cooperation, UNICEF, and the US National Institutes of Health.

Mycotoxin Exposure in Pregnancy and Birth Outcomes

In addition to the primary outcomes and exposures, the SHINE trial measured a large variety of complementary covariates and outcomes. This includes mycotoxin exposure and the birth outcomes of the children involved. Mycotoxins are toxic secondary metabolites of molds which contaminate staple foods of the region, including maize and groundnuts. Communities are often dependent on staple foods for a large portion of their diet, yet little research has been done into chronic mycotoxin exposure in humans, especially during pregnancy.

The objective of our project is to characterize pregnancy exposure to multiple mycotoxins and their relation to birth outcomes in the SHINE trial. We hypothesize exposure to the mycotoxins aflatoxin, fumonisin, and deoxynivalenol, are important contributing components to adverse birth outcomes globally. Dr. Laura Smith is a co-investigator on this trial. Funding is provided by National Institutes of Health (1R21 ES023980-01A1).

Establishing the Link between Mycotoxin Exposure, Gut Dysfunction and Stunting in Zimbabwean Infants

Environmental enteropathy (EED), or enteropathy caused by environmental exposures, is thought to be associated with stunting and be on the causal pathway for the interventions addressed in SHINE trial. A variety of environmental factors may influence EED in children, including mycotoxins. The objective of this project will be to characterize the potential association between mycotoxin exposure, gut dysfunction and stunting in participating children from the SHINE trial. Dr. Laura Smith is a co-investigator on this trial. Funding is provided by the Bill and Melinda Gates Foundation (OPP1066254).

Long term, we hope to understand the effect of mycotoxin exposure on maternal and child health in Zimbabwe, and help to inform and develop more effective child health interventions and food safety policy globally.

Publications and Presentations

Humphrey JH, Mbuya MN, Ntozini R, Moulton LH, Stoltzfus RJ, Tavengwa NV, Mutasa K, Majo F, Mutasa B, Mangwadu G, Chasokela CM Chigumira A, Chasekwa B, Smith LE, Tielsch JM, Jones AJ, Manges AR, Maluccio JA, and Prendergast AJ. Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial. The Lancet Global Health. 2019;7(1):e132-47.

Abstract

Background: Child stunting reduces survival and impairs neurodevelopment. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF) on stunting and anaemia in in Zimbabwe.

Methods: We did a cluster-randomised, community-based, 2 × 2 factorial trial in two rural districts in Zimbabwe. Clusters were defined as the catchment area of between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Women were eligible for inclusion if they permanently lived in clusters and were confirmed pregnant. Clusters were randomly assigned (1:1:1:1) to standard of care (52 clusters), IYCF (20 g of a small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counselling; 53 clusters), WASH (construction of a ventilated improved pit latrine, provision of two handwashing stations, liquid soap, chlorine, and play space plus hygiene counselling; 53 clusters), or IYCF plus WASH (53 clusters). A constrained randomisation technique was used to achieve balance across the groups for 14 variables related to geography, demography, water access, and community-level sanitation coverage. Masking of participants and fieldworkers was not possible. The primary outcomes were infant length-for-age Z score and haemoglobin concentrations at 18 months of age among children born to mothers who were HIV negative during pregnancy. These outcomes were analysed in the intention-to-treat population. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes that had an important statistical interaction between the interventions. This trial is registered with ClinicalTrials.gov, number NCT01824940.

Findings: Between Nov 22, 2012, and March 27, 2015, 5280 pregnant women were enrolled from 211 clusters. 3686 children born to HIV-negative mothers were assessed at age 18 months (884 in the standard of care group from 52 clusters, 893 in the IYCF group from 53 clusters, 918 in the WASH group from 53 clusters, and 991 in the IYCF plus WASH group from 51 clusters). In the IYCF intervention groups, the mean length-for-age Z score was 0·16 (95% CI 0·08–0·23) higher and the mean haemoglobin concentration was 2·03 g/L (1·28–2·79) higher than those in the non-IYCF intervention groups. The IYCF intervention reduced the number of stunted children from 620 (35%) of 1792 to 514 (27%) of 1879, and the number of children with anaemia from 245 (13·9%) of 1759 to 193 (10·5%) of 1845. The WASH intervention had no effect on either primary outcome. Neither intervention reduced the prevalence of diarrhoea at 12 or 18 months. No trial-related serious adverse events, and only three trial-related adverse events, were reported.

Interpretation: Household-level elementary WASH interventions implemented in rural areas in low-income countries are unlikely to reduce stunting or anaemia and might not reduce diarrhoea. Implementation of these WASH interventions in combination with IYCF interventions is unlikely to reduce stunting or anaemia more than implementation of IYCF alone.

Funding: Bill & Melinda Gates Foundation, UK Department for International Development, Wellcome Trust, Swiss Development Cooperation, UNICEF, and US National Institutes of Health.

Prendergast AJ, Chasekwa B, Evans C, Mutasa K, Mbuya MN, Stoltzfus RJ, Smith LE, Majo FD, Tavengwa NV, Mutasa B, Mangwadu GT, Chasokela CM, Chigumira A, Moulton LH, Ntozini R, and Humphrey JH. Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on stunting and anaemia among HIV-exposed children in rural Zimbabwe: a cluster-randomised controlled trial. The Lancet Child & Adolescent Health. 2018 Dec 18.

Abstract

Background: Children exposed to HIV have a high prevalence of stunting and anaemia. We aimed to test the effect of improved infant and young child feeding (IYCF) and improved water, sanitation, and hygiene (WASH) on child linear growth and haemoglobin concentrations.

Methods: We did a cluster randomised 2 × 2 factorial trial in two districts in rural Zimbabwe. Women were eligible for inclusion if they permanently lived in the trial clusters (ie, the catchment area of between one and four village health workers employed by the Zimbabwean Ministry of Health and Child Care) and were confirmed pregnant. Clusters were randomly allocated to standard of care (52 clusters); IYCF (20 g small-quantity lipid-based nutrient supplement daily for infants from 6 months to 18 months, complementary feeding counselling with context-specific messages, longitudinal delivery, and reinforcement; 53 clusters); WASH (ventilated, improved pit latrine, two hand-washing stations, liquid soap, chlorine, play space, and hygiene counselling; 53 clusters); or IYCF plus WASH (53 clusters). Participants and fieldworkers were not masked. Our co-primary outcomes were length for age Z score and haemoglobin in infants at 18 months of age. Here, we report these outcomes in the HIV-exposed children, analysed by intention to treat. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes with an important statistical interaction between the interventions. The trial is registered at ClinicalTrials.gov (NCT01824940) and is now complete.

Findings: Between Nov 22, 2012, and March 27, 2015, 726 HIV-positive pregnant women were included in the trial. 668 children were evaluated at 18 months (147 from 46 standard of care clusters; 147 from 48 IYCF clusters; 184 from 44 WASH clusters; 190 from 47 IYCF plus WASH clusters). Of the 668 children, 22 (3%) were HIV-positive, 594 (89%) HIV-exposed uninfected, and 52 (8%) HIV-unknown. The IYCF intervention increased mean length for age Z score by 0·26 (95% CI 0·09–0·43; p=0·003) and haemoglobin concentration by 2·9 g/L (95% CI 0·90–4·90; p=0·005). 165 (50%) of 329 children in the non-IYCF groups were stunted, compared with 136 (40%) of 336 in the IYCF groups (absolute difference 10%, 95% CI 2–17); and the prevalence of anaemia was also lower in the IYCF groups (45 [14%] of 319) than in the non-IYCF groups (24 [7%] of 329; absolute difference 7%, 95% CI 2–12). The WASH intervention had no effect on length or haemoglobin concentration. There were no trial-related adverse or serious adverse events.

Interpretation: Since HIV-exposed children are particularly vulnerable to undernutrition and responded well to improved complementary feeding, IYCF interventions could have considerable benefits in areas of high antenatal HIV prevalence. However, elementary WASH interventions did not lead to improvements in growth.

Funding: Bill & Melinda Gates Foundation, UK Aid, Wellcome Trust, Swiss Development Cooperation, US National Institutes of Health, and UNICEF.

Chasekwa B, Maluccio JA, Ntozini R, Moulton LH, Wu F, Smith LE, Matare CR, Stoltzfus RJ, Mbuya MMN, Tielsch JM, Martin SL, Jones A, Humphrey JH, and Fielding K. Measuring wealth in rural communities: Lessons from the Sanitation, Hygiene, Infant Nutrition Efficacy (SHINE) Trial. Under Review. PLoS one.2018; 13(6): e0199393

Abstract

Background: Poverty and human capital development are inextricably linked and therefore research on human capital typically incorporates measures of economic well-being. In the context of randomized trials of health interventions, for example, such measures are used to: 1) assess baseline balance; 2) estimate covariate-adjusted analyses; and 3) conduct subgroup analyses. Many factors characterize economic well-being, however, and analysts often generate summary measures such as indices of household socio-economic status or wealth. In this paper, a household wealth index is developed and tested for participants in the cluster-randomized Sanitation, Hygiene, Infant Nutrition Efficacy (SHINE) trial in rural Zimbabwe.

Methods: Building on the approach used in the Zimbabwe Demographic and Health Survey (ZDHS), we combined a set of housing characteristics, ownership of assets and agricultural resources into a wealth index using principal component analysis (PCA) on binary variables. The index was assessed for internal and external validity. Its sensitivity was examined considering an expanded set of variables and an alternative statistical approach of polychoric PCA. Correlation between indices was determined using the Spearman’s rank correlation coefficient and agreement between quintiles using a linear weighted Kappa statistic. Using the 2015 ZDHS data, we constructed a separate index and applied the loadings resulting from that analysis to the SHINE study population, to compare the wealth distribution in the SHINE study with rural Zimbabwe.

Results: The derived indices using the different methods were highly correlated (r>0.9), and the wealth quintiles derived from the different indices had substantial to near perfect agreement (linear weighted Kappa>0.7). The indices were strongly associated with a range of assets and other wealth measures, indicating both internal and external validity. Households in SHINE were modestly wealthier than the overall population of households in rural Zimbabwe.

Conclusion: The SHINE wealth index developed here is a valid and robust measure of wealth in the sample

Smith LE, Mbuya MN, Prendergast AJ, Turner PC, Rukobo, S, Humphrey JH, Nelson, RJ, Chigumira A, Kembo G and Stoltzfus RJ. Determinants of Recent Aflatoxin Exposure among Pregnant Women in Rural Zimbabwe. Molecular Nutrition and Food Research. 2017; 61(9): 1601049. doi: 10.1002/mnfr.201601049.

Abstract

Scope: Aflatoxins (AFs) are toxic secondary metabolites of Aspergillus species that contaminate staple foods such as maize and groundnuts. AF exposure during pregnancy has been associated with adverse birth outcomes in limited-scale surveys in sub-Saharan Africa. The objective of this study was to describe the determinants of AF exposure, using urinary aflatoxin M1 (AFM1) biomarkers and data generated by the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial for rural Zimbabwean women in early pregnancy. Sanitation Hygiene Infant Nutrition Efficacy is a large, cluster-randomized community-based trial in Zimbabwe designed to investigate the independent and combined effects of nutrition and hygiene interventions on early child growth.

Methods and Results: Urine samples collected from 1580 pregnant women in rural Zimbabwe at median gestational age of 13.9 wk were measured for AFM1. AFM1 was detected in 30% of samples (median of exposed, 162 pg AFM1/mg creatinine; range 30-6046 pg AFM1/mg). In multivariable ordinal logistic models, geographical location (p<0.001), seasonality (p < 0.001) and dietary practices (p = 0.011) were significant predictors of urinary AFM1.

Conclusion: This is the largest AF biomarker survey conducted in Zimbabwe, and demonstrated frequent exposure in pregnant women with clear temporal and spatial variability in AF biomarker levels.

Smith LE, Prendergast AJ, Turner, PC, Humphrey, JH, and Stoltzfus RJ.  Aflatoxin exposure during pregnancy, maternal anemia and adverse birth outcomes: a review. American Journal of Tropical Medicine and Hygiene. 2017; 96(4): 770-776.​

Abstract

Pregnant women and their developing fetuses are vulnerable to multiple environmental insults, including exposure to aflatoxin, a mycotoxin that may contaminate as much as 25% of the world food supply. We reviewed and integrated findings from studies of aflatoxin exposure during pregnancy and evaluated potential links to adverse pregnancy outcomes. We identified 27 studies (10 human cross-sectional studies and 17 animal studies) assessing the relationship between aflatoxin exposure and adverse birth outcomes or anemia. Findings suggest that aflatoxin exposure during pregnancy may impair fetal growth. Only one human study investigated aflatoxin exposure and prematurity, and no studies investigated its relationship with pregnancy loss, but animal studies suggest aflatoxin exposure may increase risk for prematurity and pregnancy loss. The fetus could be affected by maternal aflatoxin exposure through direct toxicity as well as indirect toxicity, via maternal systemic inflammation, impaired placental growth, or elevation of placental cytokines. The cytotoxic and systemic effects of aflatoxin could plausibly mediate maternal anemia, intrauterine growth restriction, fetal loss, and preterm birth. Given the widespread exposure to this toxin in developing countries, longitudinal studies in pregnant women are needed to provide stronger evidence for the role of aflatoxin in adverse pregnancy outcomes, and to explore biological mechanisms. Potential pathways for intervention to reduce aflatoxin exposure are urgently needed, and this might reduce the global burden of stillbirth, preterm birth, and low birthweight.

Smith LE, Prendergast AJ, Turner P, Mbuya MN, Mutasa K, Kembo G, Stoltzfus RJ and the SHINE Trial Group. The potential role of mycotoxins as a contributor to stunting in the SHINE Trial. Clinical and Infectious Diseases 2015. 71 Suppl 7: S733-7.

Abstract

Children in developing countries experience multiple exposures that are harmful to their growth and development. An emerging concern is frequent exposure to mycotoxins that contaminate a wide range of staple foods, including maize and groundnuts. Three mycotoxins are suspected to contribute to poor child health and development: aflatoxin, fumonisin, and deoxynivalenol. We summarize the evidence that mycotoxin exposure is associated with stunting, and propose that the causal pathway may be through environmental enteric dysfunction (EED) and disturbance of the insulin-like growth factor 1 (IGF-1) axis. The objectives of this substudy are to assess the relationship between agricultural and harvest practices and mycotoxin exposure; to evaluate associations between mycotoxin exposure and child stunting; and to investigate EED as a potential pathway linking mycotoxin exposure to child stunting, to inform potential areas for intervention.

Desai A, Smith LE, Mbuya M, Chigumira A, Fundira D, Tavengwa NV, Malaba TR, Majo F, Humphrey JH, Stoltzfus RJ and the SHINE Trial Group. The SHINE Trial infant feeding intervention:  Pilot study of effects on maternal learning and infant diet quality in rural Zimbabwe. Clinical and Infectious Diseases 2015. 71 Suppl 7: S710-715.

Abstract

The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial is designed to measure the independent and combined effects of improved water, sanitation, and hygiene and improved infant feeding on child stunting and anemia in Zimbabwe. We developed and pilot-tested the infant feeding intervention delivered by 9 village health workers to 19 mothers of infants aged 7-12 months. Between September 2010 and January 2011, maternal knowledge was assessed using mixed methods, and infant nutrient intakes were assessed by 24-hour recall. We observed positive shifts in mothers' knowledge. At baseline, 63% of infants met their energy requirement and most did not receive enough folate, zinc, or calcium; none met their iron requirement. Postintervention, all infants received sufficient fat and vitamin A, and most consumed enough daily energy (79%), protein (95%), calcium (89%), zinc (89%), folate (68%), and iron (68%). The SHINE trial infant feeding intervention led to significant short-term improvements in maternal learning and infant nutrient intakes.

Smith, LE, Stoltzfus, RJ, and A Prendergast. Food chain mycotoxin exposure, gut health and impaired growth: A conceptual framework. Advances in Nutrition. 2012; 3: 526-531.

Abstract

Childhood stunting is an important and intractable public health problem that underlies ~20% of deaths among children aged <5 y in developing countries. Environmental enteropathy (EE), a subclinical condition of the small intestine characterized by reduced absorptive capacity and increased intestinal permeability, is almost universal among children in developing countries and may mediate stunting. However, the etiology of EE is poorly understood. Mycotoxins are metabolites of fungi that frequently contaminate the staple foods of children living in developing countries. We review evidence from human and animal studies that exposure to mycotoxins, particularly aflatoxin (AF), fumonisin (FUM), and deoxynivaenol (DON), may impair child growth. Although these toxins have distinct actions, they all mediate intestinal damage through: 1) inhibition of protein synthesis (AF, DON); 2) an increase in systemic proinflammatory cytokines (DON); and 3) inhibition of ceramide synthase (FUM). The intestinal pathology that arises from mycotoxin exposure is very similar to that of EE. We propose that future studies should address the role of mycotoxins in the pathogenesis of EE and evaluate interventions to limit mycotoxin exposure and reduce childhood stunting.

Our Team

Laura Smith

Laura Smith

Assistant Professor

Epidemiology and Environmental Health

Jean H. Humphrey, ScD - Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore MD, USA; Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe

Mduduzi N. N. Mbuya, PhD - Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore MD, USA; Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe; Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA; Global Alliance for Improved Nutrition, Washington, DC, USA

Robert Ntozini - Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe

Lawrence H. Moulton, PhD - Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore MD, USA

Rebecca J. Stoltzfus, PhD - Division of Nutritional Sciences, Cornell University, Ithaca, NY, USA

Naume V. Tavengwa, MSW - Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe

Kuda Mutasa, MPH - Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe

Florence Majo, RN - Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe

Batsirai Mutasa, MPH - Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe

Goldberg Mangwadu, MSc – Ministry of Health and Child Care, Harare, Zimbabwe

Cynthia M. Chasokela, PhD – Ministry of Health and Child Care, Harare, Zimbabwe

Ancikaria Chigumira, MSc – Ministry of Health and Child Care, Harare, Zimbabwe

Bernard Chasekwa, MSc - Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe

James M. Tielsch, PhD - Department of Global Health, Milken Institute School of Public Health, George Washington University, Washington, DC, USA

Andrew D. Jones, PhD - Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, USA

Amee R. Manges, PhD - University of British Columbia, Vancouver, BC, Canada

John A. Maluccio, PhD - Middlebury College, Middlebury, VT, USA

Andrew J. Prendergast, DPhil - Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore MD, USA; Zvitambo Institute for Maternal and Child Health Research, Harare, Zimbabwe; Blizard Institute, Queen Mary University of London, London, UK

Paul Turner, PhD - Maryland Institute for Applied Environmental Health, School of Public Health, University of Maryland, College Park, Maryland.

George Kembo – Food and Nutrition Council, Zimbabwe

The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) Trial Team (https://doi.org/10.1093/cid/civ844)