Evaluation of urinary aflatoxin M1 levels in children under 5 years from the Oshana region, Namibia, and association with child growth

Abstract

Aflatoxin exposure poses a serious health concern in developing countries particularly to vulnerable children’s populations, due to frequent consumption of contaminated foods. Exposure to aflatoxin B1 (AFB1) has been documented to cause adverse health effects including growth impairment in children. Aflatoxin M1 (AFM1), a hydroxylated product of AFB1, is a validated urinary biomarker for recent dietary exposure to AFB1. This study aimed to determine the exposure of children to AFB1 through urinary AFM1 levels and associate the exposure with growth impairment in children under 5 years in the Oshana region of Namibia. A cross-sectional quantitative design was employed for this study, purposively recruiting 126 non-breast-feeding children under 5 years. Child anthropometric measurements were taken to assess nutritional status using Emergency Nutrition Assessment (ENA) software. A total of 126 urine samples were collected and analysed for AFM1 using Enzyme-linked Immunosorbent Assay (ELISA). All the data were analysed using Microsoft excel and IBM® SPSS® Statistics version 27. Stunting (31%) was the most frequently observed growth impairment followed by underweight (12%) and wasting (5.6%). AFM1 was quantified in 13% of the urine samples, with a mean concentration of 0.23 ± 0.15 ng/ml, indicating recent dietary exposure to AFB1. No association was found between AFM1 urinary biomarker and growth indicators among children (p > 0.05) using chi-square analysis. This study revealed the presence of AFM1 in children’s urine, indicating a recent exposure of children to AFB1 through contaminated foods. While the prevalence of stunting, underweight and wasting was high among the studied population, there was no association between these growth indicators and urinary AFM1. Appropriate complementary feeding practices are urgently required to prevent malnutrition among children, and interventions to mitigate contamination of foods with aflatoxins to prevent exposure of children to mycotoxins should be prioritized. Not applicable.