Browsing by Author "Stoltzfus, Rebecca"

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Childhood dietary exposure of aflatoxins and fumonisins in Tanzania: A review
(Taylor & Francis Online, 2020-12-24) Mollay, Clara; Kassim, Neema; Stoltzfus, Rebecca; Kimanya, Martin
Aflatoxins (AFs) and Fumonisins (FBs) are common contaminants of maize, from secondary metabolites of fungi. Presence of AFs and FBs in maize-based complimentary food is evident in various studies conducted in Tanzania and elsewhere. Consequently, Infant and Young children (IYC) aged between 6 and 24 months in Tanzania who consume monotonous maize-based foods are at a high risk of exposure to these toxins. The AF or FB exposures have been linked to low awareness and inadequate knowledge or limited skills of IYC feeding practices among mothers and caregivers. This review reveals that more researches are needed to identify appropriate feeding practices in Tanzania to improve child growth. Meanwhile, stakeholders should direct efforts on education to subsistence farmers including mothers and caregivers on interventions to minimize mycotoxin contamination of cereal and nut-based complementary foods in the country.
Comparison of Methods to Assess Adherence to Infant and Young Child Feeding Practices and Provision of Low-Aflatoxin Porridge Flours in a Community-Based Intervention Trial
(MDPI, 2024-12-13) Phillips, Erica; Kayanda, Rosemary; Kassim, Neema; Ngure, Francis; Turner, Paul; Stoltzfus, Rebecca
Background: Levels of adherence to recommended protocols in an intervention trial can affect outcomes and confound the results. To broaden the evidence about the selection and utility of adherence measures in varying contexts, we describe the level of adherence to the Mycotoxin Mitigation Trial (MMT) randomized intervention using caregiver-reported survey questions and compare inferences of adherence between multi-module surveys and interactive 24 h dietary recalls based on our program theory. Methods: The MMT was a two-arm cluster-randomized trial conducted in 52 health facilities (clusters) in central Tanzania. Surveys were conducted with all trial participants at three time points and dietary recalls were conducted in a cohort at 12 mo. Results: The 12 mo survey was conducted with 2112 caregivers and the 18 mo survey was conducted with 2527 caregivers. A cohort of participants (n = 282, 20 clusters) was selected for dietary recalls, balanced by arm. Reported feeding of blended porridge flours, whether MMT-provided or own-sourced, was high at 12 and 18 mo, between 73 and 95%, with only slight differences between the surveys and recalls. Inferences were similar for continuation of breastfeeding, feeding frequency, and dietary diversity. Only the amount of porridge fed the previous day differed statistically by method, with higher amounts reported in the recalls compared to the survey. Conclusions: Detailed analysis of reported behaviors, based on the MMT program theory, supports high adherence to the recommended trial behaviors. Survey data and 24 h dietary recalls were convergent for almost all indicators, strengthening the trial’s conclusions and allowing for either method to be selected for similar research.
Complementary feeding in Kongwa, Tanzania: Findings to inform a mycotoxin mitigation trial.
(John Wiley & Sons Ltd., 2021-05-04) Mollay, Clara; Kassim, Neema; Stoltzfus, Rebecca; Kimanya, Martin
Complementary feeding of 6- to 24-month-old infants and young children with adequate, safe and developmentally appropriate food is essential to child health. Inappropriate complementary foods and feeding practices are linked to the high incidences of undernutrition among infant and young children in most developing countries, including Tanzania. Mycotoxin risk is an additional concern, given the documented presence of aflatoxin and fumonisin in food systems of Africa, especially maize and groundnut. In preparation for a trial of mycotoxin mitigation, we conducted focus group discussions and recipe trials to explore complementary foods and feeding practices in Kongwa, a rural district of central Tanzania. Sixty mothers of infants from 6 to 18 months of age in five villages across the district were purposefully sampled. During focus group discussions, mothers reported to mostly feed their children with cereal and groundnut-based foods as thin or thick porridges. The most common porridge preparations contained cereal (mostly, maize) ranging from 66.7% to 80.0% by weight and groundnuts from 7.7% to 33.3%. The ratio of cereal to groundnut ranged from 3:1 to 4:1. For the recipe trial sessions, mothers chose similar ingredients reported during discussions to prepare complementary foods. The reliance on maize and groundnuts in complementary foods predisposes the children to undernutrition and exposure to aflatoxins and fumonisins. These formative research results suggest multiple intervention points to improve complementary feeding and reduce mycotoxin exposure in this population, including education messages package on feeding practices, mycotoxin control practices and complementary food formulation.
The effect of an intervention to reduce aflatoxin consumption from 6 to 18 mo of age on length-for-age z-scores in rural Tanzania: a cluster-randomized trial
(Elsevier, 2025-02-01) Phillips, Erica; Ngure, Francis; Kassim, Neema; Turner, Paul; Makule, Edna; Smith, Laura; Makori, Nyabasi; Cramer, Benedikt; Humpf, Hans-Ulrich; Nelson, Rebecca; Stoltzfus, Rebecca
Background Linear growth faltering continues to negatively affect children in low- and middle-income countries and is associated with poor cognitive, developmental, and educational outcomes. Laboratory and observational data suggest that aflatoxin (AF) is a contributor to stunting. Objective The Mycotoxin Mitigation Trial was a cluster-randomized, community-based 2-group trial conducted in Kongwa District, Tanzania, between 2018 and 2020. The trial assessed whether a 12-mo intervention to reduce AF consumption increased length-for-age z-scores (LAZ) at 18 mo. Methods Low-AF maize and groundnut flours were provided to the intervention group each month; skin lotion was distributed to the control group monthly. Infant and young child feeding education was delivered equally in 52 health facilities (clusters). Anthropometry and the AF blood biomarker serum AF-albumin (AF-alb) were assessed at 6, 12, and 18 mo of age. Outcomes were analyzed as intention-to-treat and per-protocol using linear mixed-effects models. Results Two thousand eight hundred forty-two maternal–infant dyads were recruited into the study. The intervention did not create a contrast in AF-alb. At 18 mo, 36% (n = 186/520) of infants had detectable levels of AF-alb compared with 54% (n = 195/364) at baseline, with no difference between groups. Mean LAZ in the intervention group at 18 mo was −1.83 (n = 1231, 95% CI: −1.93, −1.73) compared to −1.90 (n = 1287, 95% CI: −1.99, −1.82) in the control group (P = 0.28). Conclusions An intervention to reduce AF exposure did not alter AF-alb nor anthropometric measures between treatment groups. Drought and agricultural data indicated less favorable conditions for toxin production, resulting in low levels of exposure in both trial arms. Annual, seasonal, and geographic heterogeneity of AF contamination make it difficult to study in an ethically designed trial. Our formative research and early trial data indicate that stunting and intermittent AF exposure continue to be a problem in this region. However, the low-AF exposure levels during the trial led to inconclusive results.
Ethical considerations in the design and conduct of a cluster-randomised mycotoxin mitigation trial in Tanzania
(Wageningen Academic Publishers, 2022-01-24) Phillips, Erica; Turner, Paul; Ngure, Francis; Kassim, Neema; Makule, Edna; Smith, Laura; Nelson, Rebecca; Stoltzfus, Rebecca
Aflatoxins are fungal metabolites that commonly contaminate staple food crops in tropical regions. Acute aflatoxin consumption in very high concentration causes aflatoxicosis and acute liver failure, while chronic, moderate levels of intake cause hepatocellular carcinoma. The effects of frequent moderate- to high-level exposure during infancy, however, is less clearly understood. Half a billion people in low- and middle-income countries continue to be exposed to aflatoxins through dietary consumption, in part because of lack of enforcement of regulatory limits and few feasible long-term mitigation options in these settings. Several epidemiologic studies have shown an association between aflatoxin exposure in infants and young children and growth failure, but strong experimental evidence is lacking. The Mycotoxin Mitigation Trial conducted in Tanzania was a cluster-randomised trial to assess the effect of a reduced aflatoxin diet on linear growth. Prior to the design and implementation of this trial, a group of multi-disciplinary and multi-national scientists reviewed literature in biomedical, public health, environmental health ethics. In this paper we outline the most salient ethical questions and dilemmas in the potential conduct of such a study and describe the ethical precedents and principles that informed our decision-making processes and ultimate study protocol.
Ethical Considerations of the Trial to Establish a Causal Linkage Between Mycotoxin Exposure and Child Stunting
(Elsevier, 2021-06-21) Phillips, Erica; Turner, Paul; Kassim, Neema; Makule, Edna; Nelson, Rebecca; Ngure, Francis; Smith, Laura; Stoltzfus, Rebecca
Objectives Aflatoxins are fungal metabolites that commonly contaminate staple crops in tropical regions. Aflatoxin is a carcinogen and consumption at high-levels can lead to acute liver failure and aflatoxicosis. Multiple epidemiologic studies have shown an association between aflatoxin exposure in infants and young children and growth failure, but strong experimental evidence is lacking. The Trial to Establish a Causal Linkage Between Mycotoxin Exposure and Child Stunting being conducted in Tanzania is a cluster-randomized trial to assess the effect of reduced aflatoxin exposure on linear growth. Methods Prior to its design and launch, the multi-disciplinary research team conducted a critical review to determine the most salient ethical questions and dilemmas in the potential conduct of such a study and debated if and how this study could be designed to meet human subject ethical criteria. This critical review included trial protocols, methodologies and historical controversies in the areas of bio-medical, public health and environmental health research. Results This critical review identified three major questions: 1) Given what is already known about aflatoxin, should a question about the effect of this toxin on child growth be studied further in human subjects? 2) If the relationship between aflatoxin and stunting can be studied in humans, what is the most ethical study design to employ? 3)What is the most ethical intervention to randomly allocate? Conclusions Based on the critical review and in alignment with human subject principles and guidelines, we concluded that it was possible to conduct such a study. The trial and intervention were designed to advance scientific knowledge, maintain a favorable risk/benefit ratio, and respect participants, among other ethical principles.
Main complementary food ingredients contributing to aflatoxin exposure to infants and young children in Kongwa, Tanzania
(Elsevier Ltd., 2021-11-23) Mollay, Clara; Kimanya, Martin; Kassim, Neema; Stoltzfus, Rebecca
Complementary foods (CFs) provided to infants and young children (IYC) in sub-Saharan Africa contain ingredients that are susceptible to aflatoxin contamination. Chronic dietary exposure to aflatoxins is associated with health consequences. This study assessed the risk of exposure of IYC (6-12-month-old) in Kongwa, Tanzania to aflatoxins through CFs. The intake of aflatoxin susceptible flours (ingredients) in CFs by 35 IYC was estimated through multiple-pass 24-hrdietary recalls. Samples of the ingredients were tested for aflatoxins using High-PerformanceLiquid Chromatography. Exposure of a child to aflatoxins was estimated by a deterministic approach. The contribution of an ingredient to the overall exposure was estimated statistically. The key ingredients of CFs consumed by the IYC were maize, sorghum, pearl millet, rice, and groundnuts (pre-or post-blended with the other ingredients). Cereal and groundnut-based CFs weregiven as thin or stiff porridge. The average per capita daily intake of CFs was 89.45 g. About 82.14% of the CF ingredients were contaminated with aflatoxin B1 (AFB1) in the range of 0.27– 317 μg/kg, with a median of 3.96 μg/kg. AFB1 exposures ranged from 0.33 to 1168 ng/kg bw/day(median of 23.06 ng/kg bw/day). The Margins of Exposure were less than 10,000 for all the IYC, signifying a public health concern. Post-blended groundnut flour, followed by maize, contributed the most to the exposure of IYC to AFB1. Groundnut and maize used as CFs in Kongwa are likelyto be the main contributors to the exposure of IYC to AFB1. Caregivers should be advised to replace maize and groundnuts with well-processed less susceptible cereals like pearl millet and other legumes, respectively.
Nutrient intake and dietary adequacy among infants in Kongwa District, Tanzania: A sub-study of the Mycotoxin Mitigation Trial
(Research Square, 2023-04-13) Kayanda, Rosemary; Phillips, Erica; Kassim, Neema; Ngure, Francis; Stoltzfus, Rebecca
Background: Early exposure to aflatoxin, a common toxin in global food systems, has been associated with child growth faltering. The Mycotoxin Mitigation Trial was a community-based cluster-randomized trial designed to assess the effect of dietary aflatoxin on stunting. The study provided low aflatoxin pre- blended porridge flour and groundnuts flour to the Intervention arm, while the same porridge recipe from home ingredients was promoted through education to the Standard of Care (SOC) arm. The objective was to isolate the effect of aflatoxin consumption while keeping dietary intake otherwise the same between the two arms. Methods: To assess dietary intake, we performed a cross-sectional study on trial participants to evaluate and compare nutrient intake and adequacy of protein, energy, lipid, iron, zinc, calcium, and vitamin A between the randomized arms of the study. Twenty paired clusters (10 per trial arm) were selected, with up to 15 households per cluster randomly selected for a structured, multi-pass 24-h recall in three different rounds of data collection at 12 months of age. Results: A total of 282 children participated. Nutrient intake was estimated from mixed models to account for clusters. The mean daily intakes of energy and lipid were 505 kcal and 13 mg respectively in the intervention and SOC while intervention children consumed slightly more proteins (13.7 g v 12.3 g, p= 0.02). There were no differences between the arms regarding the consumption of iron, zinc, calcium, or vitamin A. Generally, Iron and zinc consumption was very low. Conclusion: At the midpoint of the trial intervention only protein consumption differed between arms. Both arms met RNI for energy, protein, and vitamin A but not for other nutrients assess.
Processing complementary foods to reduce mycotoxins in a medium scale Tanzanian mill: A hazard analysis critical control point (HACCP) approach
(Elsevier, 2024-03-22) Ngure, Francis; Makule, Edna; Mgongo, William; Phillips, Erica; Kassim, Neema; Stoltzfus, Rebecca; Nelson, Rebecca
Designing and implementing processing procedures for producing safe complementary foods in dynamic and unregulated food systems where common food staples are frequently contaminated with mycotoxins is chal- lenging. This paper presents lessons about minimizing aflatoxins (AF) in groundnut flour and AF and/or fumonisins (FUM) in maize and groundnut pre-blended flour for complementary feeding in the context of a dietary research intervention in rural Tanzania. The flours were processed in collaboration with Halisi Products Limited (Halisi), a medium scale enterprise with experience in milling cereal-based flours in Arusha, Tanzania. Using a hazard analysis critical control point (HACCP) approach for quality assurance, two critical control points (CCPs) for AF in processing the pre-blended flour were identified: 1) screening maize before procurement, and 2) blending during the processing of each constituent flour. Blending of maize flour was also identified as a CCP for FUM. Visual inspection during screening and sorting were identified as important control measures for reducing AF, but these steps did not meet the criteria for a CCP due to lack of objective measurement and verifiable standards for AF. The HACCP approach enabled the production of low AF (<5 μg/kg) and FUM (<2 μg/g) flours with low rejection rates for the final products. The paper presents practical lessons that could be of value to a range of commercial processors in similar low- and middle-income contexts who are keen on improving food quality.
Protocol for the trial to establish a causal linkage between mycotoxin exposure and child stunting: a cluster randomized trial.
(BMC Public Health, 2020-05-01) Phillips, Erica; Ngure, Francis; Smith, Laura; Makule, Edna; Turner, Paul; Nelson, Rebeca; Kimanya, Martin; Stoltzfus, Rebecca; Kassim, Neema
Background: The number of stunted children has fallen globally but continues to increase in Africa. Stunting is estimated to contribute to 14–17% of child deaths under 5 years of age and is a risk factor for poor cognitive and motor development and educational outcomes. Inadequate dietary intake and disease are thought to be the immediate causes of undernutrition and stunting. However, improving infant diets through complementary feeding interventions has been shown to only modestly reduce stunting. Multiple observational studies demonstrate a dose response relationship between fetal and post-natal aflatoxin exposure and reduced linear growth. Methods: This community-based cluster randomized trial will measure the effect of a reduced aflatoxin diet on length-for-age Z scores at 18 months in central Tanzania. All 52 health facilities in the Kongwa District of Dodoma Region were randomized into two groups. Starting at 6 months of age, participants in the intervention group receive a low-aflatoxin pre-blended porridge flour containing maize and groundnut (ratio 4:1 respectively) and lowaflatoxin groundnut flour, whereas in the control group the same porridge mix and groundnut flour are promoted through education but acquired by the household. Both groups will receive the same infant and young child feeding education and a thermos flask. A total of 3120 infants between 6 weeks and 3 months of age will be recruited into the study over 1 year. Data will be collected four times – at recruitment and when the infants are 6, 12 and 18 months of age. In a cohort of 600 infants, additional data will be collected at 9 and 15 months of age. The primary outcome is length-for-age at 18 months. Secondary outcomes include the Z scores for weight-for-age, middle upper arm circumference and head circumference, and the blood biomarker aflatoxin-albumin in the full sample, with the urine biomarker aflatoxin M1 analyzed in the cohort only. Discussion: Better understanding the etiology of childhood stunting can lead to more appropriate interventions and policies to further reduce linear growth faltering and meet the Sustainable Development Goals
Provision of low‐aflatoxin local complementary porridgeflour reduced urinary aflatoxin biomarker in childrenaged 6–18 months in rural Tanzania
(Wiley Online Library, 2023-03-09) Kassim, Neema; Ngure, Francis; Smith, Laura; Turner, Paul; Stoltzfus, Rebecca; Makule, Edna; Makori, Nyabasi; Phillips, Erica
Aflatoxins are toxic secondary metabolites of fungi that colonize staple food crops, such as maize and groundnut, frequently used in complementary feeding. In preparation for a large trial, this pilot study examined if provision of a low‐aflatoxin infant porridge flour made from local maize and groundnuts reduced the prevalence of a urinary aflatoxin biomarker in infants. Thirty‐six infants aged 6–18 months were included from four villages in Kongwa District, Tanzania. The study was conducted over 12 days with a three‐day baseline period and a 10 days where low‐AF porridge flour was provided. Porridge intake of infants was assessed using quantitative 24‐h recalls by mothers. Household food ingredients used in infant porridge preparation and urine samples were collected on Days 1–3 (baseline) and 10–12 (follow‐up). Aflatoxins were measured in household foods, and AFM1 was measured in urine. At baseline and follow‐up, 78% and 97%, respectively, of the infants consumed porridge in the previous 24 h, with a median volume of 220 mL (interquartile range [IQR]: 201, 318) and 460 mL (IQR: 430, 563), respectively (p < 0.001). All 47 samples of homemade flour/ingredients were contaminated with AFs (0.3–723 ng/g). The overall prevalence of individuals with detectable urinary AFM1 was reduced by 81%, from 15/36 (42%) at baseline to 3/36 (8%) at follow‐ up (p = 0.003). Provision of low‐aflatoxin porridge flour was acceptable to caregivers and their infants and successfully reduced the prevalence of detectable urinary AFM1 in infants, thus, confirming its potential to be tested in future large‐scale health outcomes trial.