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Background: Aflatoxin and fumonisin are toxic food contaminants. Knowledge about effects of their exposure and coexposure on child growth is inadequate.Objective: We investigated the association between child growth and aflatoxin and fumonisin exposure in Tanzania.Methods: A total of 166 children were recruited at 6–14 months of age and studied at recruitment, and at the 6th and 12th month following recruitment. Blood and urine samples were collected and analyzed for plasma aflatoxin–albumin adducts (AF-alb) using ELISA, and urinary fumonisin B1 (UFB1) using liquid chromatography–mass spectrometry, respectively. Anthropometric measurements were taken, and growth index z-scores were computed.Results: AF-alb geometric mean concentrations (95% CIs) were 4.7 (3.9, 5.6), 12.9 (9.9, 16.7), and 23.5 (19.9, 27.7) pg/mg albumin at recruitment, 6 months, and 12 months from recruitment, respectively. At these respective sampling times, geometric mean UFB1 concentrations (95% CI) were 313.9 (257.4, 382.9), 167.3 (135.4, 206.7), and 569.5 (464.5, 698.2) pg/mL urine, and the prevalence of stunted children was 44%, 55%, and 56%, respectively. UFB1 concentrations at recruitment were negatively associated with length-for-age z-scores (LAZ) at 6 months (p = 0.016) and at 12 months from recruitment (p = 0.014). The mean UFB1 of the three sampling times (at recruitment and at 6 and 12 months from recruitment) in each child was negatively associated with LAZ (p < 0.001) and length velocity (p = 0.004) at 12 months from recruitment. The negative association between AF-alb and child growth did not reach statistical significance.Conclusions: Exposure to fumonisin alone or coexposure with aflatoxins may contribute to child growth impairment.Citation: Shirima CP, Kimanya ME, Routledge MN, Srey C, Kinabo JL, Humpf HU, Wild CP, Tu YK, Gong YY. 2015. A prospective study of growth and biomarkers of exposure to aflatoxin and fumonisin during early childhood in Tanzania. Environ Health Perspect 123:173–178; http://dx.doi.org/10.1289/ehp.1408097

Anemia is a global health problem affecting most developing countries. We examined the prevalence of anemia and its predictors among children under 5 years of age in Arusha District, Tanzania. Random sampling technique was used to identify 436 children aged 6–59 months. Anemia status was assessed by measuring hemoglobin concentration from blood sample obtained from a finger prick and HemoCue® Hb 201+ photometer. Demographic information and dietary intake data were collected using a standardized questionnaire. Anemia cut-off points were defined according to World Health Organization standards for children aged 6–59 months. Logistic regression using backward procedure was used to estimate odds ratios (ORs) at 95% confidence intervals (CIs). Prevalence rate of anemia among under-fives was found to be 84.6% (n=369). Multivariable logistic regression identified the following predictors of anemia; low birth weight (adjusted OR (AOR): 2.1, 95% CI: 1.1–3.8), not consuming meat (AOR: 6.4, 95% CI: 3.2–12.9), not consuming vegetables (AOR: 2.1, 95% CI: 1.1–4.1), drinking milk (AOR: 2.5, 95% CI: 1.1–5.2), and drinking tea (AOR: 4.5, 95% CI: 1.5–13.7). It was concluded that low birth weight and dietary factors (ie, low or nonconsumption of iron-rich foods like meat, vegetables, and fruits) were predictors of anemia among under-five children living in this rural setting. Community education on exclusive breastfeeding and introduction of complementary foods should be improved. Mothers and caretakers should be educated about nutrition, in general, as well as potential use of micronutrient powder to improve the nutritional quality of complementary foods.

In June 2016, an outbreak of an unknown disease was reported to affect clusters of families in two regions of the central part of Tanzania. A rapid epidemiological survey was conducted in the affected villages, with a detailed house-to-house survey in selected households. A total of 68 cases occurred between 14 May and 14 November 2016, of which 20 died, making a case fatality rate of 30%. Over 50% of the cases were below the age of 15 years. The cases presented with jaundice (n=60), abdominal pain (n=59), vomiting (n=56), diarrhoea (n=34) and ascites (n=32). The responsible food item appeared to be home grown maize. The rate ratio indicated that the occurrence of illnesses was associated with ingestion of food contaminated with high levels of aflatoxins (contamination range: 10-51,100 μg/kg and 2.4-285 μg/kg for case and control households, respectively). Serum aflatoxin biomarker indicated that cases were more likely to have higher than 1000 pg/mg aflatoxin-albumin adduct level in their sera compared to controls (Odds Ratio = 13.5; 95% confidence intervals = 1.5-165.3; range of aflatoxin-albumin adduct level = 36- 32,800 pg/mg for cases and 10-4020 pg/mg for controls). Beside aflatoxins, maize samples were also contaminated with high levels of fumonisins (range of contamination; 945-12,630 μg/kg) with 8 of 10 samples analysed from case households co-contaminated with both toxins at levels above the maximum limit of 5 or 10 μg/kg set for AFB1 or total aflatoxins and 2,000 μg/kg for fumonisins. Clinical presentation and high levels of aflatoxin in food samples coupled with high levels of serum aflatoxin-albumin adducts among the cases support the causal role of aflatoxins.

Infants consuming maize-based foods are at a high risk of exposure to fumonisins. This study explored the association between exposure of fumonisins from maize and growth retardation among infants in Tanzania. Mothers of 215 infants consented for their children to participate in this study. We estimated maize intake for each child by twice conducting a 24 h dietary recall and fumonisins level in the maize, using HPLC. Fumonisins exposure for each child was estimated by combining his/her maize intake and the fumonisins level in the maize. Of the infants, 191 consumed maize. The maize consumed by 131 infants contained fumonisins at levels varying from 21 to 3201 μg/kg. Fumonisins exposure in 26 infants exceeded the provisional maximum tolerable daily intake of 2 μg/kg body weight. At 12 months of age, infants exposed to fumonisins intakes above the provisional maximum tolerable daily intake of 2 μg/kg bodyweight were significantly shorter by 1.3 cm and 328 g lighter. It appears that the exposure to fumonisins is associated with growth retardation. This is the first study to report an association between fumonisins exposures and growth retardation.

Scope The study aims to evaluate the status of dietary exposure to aflatoxin and fumonisin in young Tanzanian children, using previously validated biomarkers of exposure. Methods and results A total of 148 children aged 12 to 22 months, were recruited from three geographically distant villages in Tanzania; Nyabula, Kigwa and Kikelelwa. Plasma aflatoxin-albumin adducts (AF-alb) and urinary fumonisin B1 (UFB1) were measured by ELISA and LC-MS, respectively. AF-alb was detectable in 84% of children, was highest in fully weaned children (p<0.01) with higher levels being associated with higher maize intake (p<0.05). AF-alb geometric mean (95% CI) was 43.2 (28.7–65.0), 19.9 (13.5–29.2) and 3.6 (2.8–4.7) pg/mg albumin in children from Kigwa, Nyabula and Kikelelwa, respectively. UFB1 was detectable in 96% of children and the level was highest in children who had been fully weaned (p<0.01). The geometric UFB1 mean (95% CI) was 327.2 (217.1–493.0), 211.7 (161.1–278.1) and 82.8 (58.3–117.7) pg/ml in Kigwa, Nyabula and Kikelelwa, respectively. About 82% of all the children were exposed to both mycotoxins. Conclusion Young children in Tanzania are chronically exposed to both aflatoxin and fumonisin through contaminated diet, although the level of exposure varies markedly between the three villages studied.

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