Aflatoxin Exposure of Lactating Mother-child Pairs and Nutritional Status of Breastfeeding Children 0-6 Months in Makueni County, Kenya

Abstract

Aflatoxins are fungal metabolites, once ingested in food, are detoxified in the liver and transferred into breast milk, urine and tissues. Their accumulation in the body can lead to malnutrition, aflatoxicosis, or cancer which are predominant in sub-Saharan Africa. The southeastern region of Kenya is prone to aflatoxin outbreaks yet exposure levels of the vulnerable population such as breastfeeding children and lactating mothers remain unclear. This study assessed aflatoxin exposure of lactating mother-child pairs, and nutritional status of breastfeeding children aged below six months. A descriptive cross-sectional study with an analytical component was conducted. Information on socio-demographic characteristics, dietary habits, breastfeeding practices, maize handling and storage practices, and weight of 170 lactating mother-breastfeeding child pairs were collected. A total of 48 breast milk and urine samples were collected from respective lactating mothers whose food samples were picked for analysis. Aflatoxins in the food sample were determined using high-performance liquid chromatography (HPLC). Quantification was done using an enzyme-linked immunosorbent assay (ELISA). Statistical analysis was done using the Statistical Package Software for Social Sciences (SPSS). The level of significance level was set at p < 0.05. Among 170 mothers interviewed, 45.3, 49.4 and 5.3% were from low-, middle- and highincome households, respectively. Of them, 48.2% had not attained basic primary education. Food consumption patterns showed a generally low dietary diversity with the mean women dietary diversity score being 3.4 (SD, 1.5), aflatoxin food score being 25%, and 45.9% of lactating mothers eating at least four (4) different foods in the preceding 24-hour period. All lactating mothers (100%) consumed maize and other cereal-based foods per week. The rate of exclusive breastfeeding was 44.1% and at least 45% used cereal-based complementary foods daily. Average breast milk intake was 82.3 (SD, 31.7) ml/kg b.w.t/day (31.6 to 157.8). About 50% sourced maize from the market, 50% never treated their maize, and at least 20% stored maize in containers that promote aflatoxin contamination. Aflatoxin was detected in 85.4% (41/48) food samples where over 90% of the positive food samples were above 10 and 2 μg/kg Kenya Bureau of Standards (KEBs) limits for total aflatoxin and aflatoxin B1, respectively. Mean concentration of total aflatoxin was 97.8 μg/kg (SD, 57.7; range 2.3 to 210.0), while aflatoxin B1 was 9.0 μg/kg (SD, 7.7; range, 0.7 to 32.3). Subsequently, mean dietary intake of total aflatoxin and aflatoxin B1 were 7.6 μg/kg/b.w.t/day (SD, 7.5; range, 0.0 to 23.9) and 0.6 (SD, 0.6; range, 0 to 1.9), respectively. Aflatoxin M1 was however detected in 77.1% (37/48) breast milk samples with about 62% exceeding 0.025 μg/kg EU limits. Mean level of aflatoxin was 35 ng/l (SD, 0.0; range 5 to 77), while mean intake was 0.47.μg/kg b.w.t/day (SD, 0.50; range, 0.0 to 1.7). All urine (100%) had aflatoxin M1 with a mean of 0. 39 ng/ml (SD, 0.16; range, 0.15 to 0.82). Total aflatoxin in mothers’ diet significantly contributed to levels of aflatoxin M1 in breastmilk (p = 0.00), and urine of breastfeeding children (p = 0.01). Aflatoxin B1 intake also influenced aflatoxin M1 in breastmilk of exclusively lactating mothers (p = 0.01). Education level negatively influenced aflatoxin B1 intake of exclusively lactating mothers (p = 0.01), while dietary diversity significantly reduced aflatoxin M1 intake of nonexclusively breastfeeding children (p = 0.04). Socioeconomic status was not a significant predictor of aflatoxin even though it showed a positive correlation with aflatoxin B1 intake (tb = 0.24, p = 0.042 and a negative correlation with aflatoxin M1 in the urine of exclusively breastfeeding children (tb = -0.35, p = 0.041). No significant correlation was reported between weight-for-age z-scores with aflatoxin exposure (pall > 0.05). However, exposure levels of both lactating mothers and breastfeeding children were extremely high with a margin of exposure (MOE) of < 10, 000. This study concludes that mothers’ diets exposed exclusively, and non-exclusively breastfeeding children aged six months and below to high aflatoxin intake in the study area. As a result, knowledge, attitude, and practices that mitigate aflatoxin contamination in diets and breast milk of lactating mothers as well as clear county government policy on the sale and distribution of aflatoxin-contaminated maize should be introduced in the study area.