The objective of this study was to assess levels of contamination of aflatoxins and fumonisins (B1+B2) in maize, ground nuts and rice produced, stored and consumed in rural households in Malawi. A total of 9 districts were selected across the country: 3 districts in North, Central and Southern regions respectively. Households were selected at random in each district where 10 maize samples were collected for laboratory analysis. A total of four districts were selected for rice and six districts for ground nuts which were also sampled the same as for maize. Aflatoxins and fumonisins were analyzed using a single step lateral flow immunochromatographic assay based on a competitive immunoassay format: specifically, the Reveal AccuScan III reader and NEOGEN test kits. The detection limit for aflatoxins was 2 μg/Kg with a quantitation range of 2 - 150 μg/Kg and that for fumonisins was 1 mg/Kg with a quantitation range of 1 - 7 mg/Kg (7ppm). In general it was found that samples in the Southern region were highly contaminated, with the Chikhwawa district having high levels of both aflatoxins and fumonisins in maize and rice. The Northern region had the least contamination with almost 95% of the samples tested having toxin levels below the regulatory limit. The maximum detected amounts of aflatoxins were 140, 210 and 18.5 μg/Kg in maize, rice and ground nuts, respectively. The maximum detected amounts of fumonisins were 7000, 7000 and 2600 μg/Kg (7, 7 and 2.6 ppm) in maize, rice and groundnuts respectively. About 20% of maize, 15% of ground nuts and 8% of rice samples exceeded the tolerable maximum limit for aflatoxins in Malawi and 10% of maize, 0% of ground nuts and 5% of rice samples exceeded the tolerable maximum limit for fumonisins in the EU and US. The Chikhwawa and Machinga districts were found to have more households with aflatoxin concentrations greater than the regulatory limit for Malawi. Aflatoxins and fumonisins were found to co-occur. In two of the samples from the Chikhwawa district, both aflatoxins and fumonisins were present in high concentrations in one of each, maize and rice samples. The levels were 105.6 μg/Kg and 7 mg/Kg in rice for aflatoxins and fumonisins respectively and 140 μg/Kg and 7 mg/Kg in maize for aflatoxins and fumonisins respectively.
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