Aflatoxins are a group of fungal toxins produced as secondary metabolites by certain strains of the ubiquitous mould species Aspergillus flavus and A. parasiticus. They are acutely toxic, carcinogenic, mutagenic, teratogenic and immunosuppresive. Aflatoxin B1 is the most prevalent and most toxic metabolite. The occurrence of aflatoxins in human food and animal feeds in Kenya is well documented. This occurrence has been associated with clinical and fatal outbreaks of aflatoxicosis in human beings and animals. In poultry, aflatoxin intoxication causes acute deaths, an acute or chronic disease, reduced growth, lowered productivity and interferes with immunity against diseases. Chicken fed on aflatoxin contaminated feeds retain aflatoxin residues in their tissues. These residues are highest in the liver, kidney and gizzard. The determination of these toxic residues is important for the clinical diagnosis of aflatoxicosis and for epidemiological investigations. As human beings are indirectly exposed to aflatoxins through consumption of meat and eggs from chicken fed on aflatoxin contaminated diets, the determination of these residues is also important in evaluating the total aflatoxin exposure to man.
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