Aflatoxins were first discovered following an epidemic of “Turkey X disease” in which over 100,000 turkeys in England suddenly became ill and died over many months in the year 1960.
Aflatoxins are a class of carcinogenic mycotoxins produced by Aspergillus fungi and are known to contaminate a large portion of the world's food supply. Two closely related species of fungi are mainly responsible for producing the aflatoxins of public health significance: Aspergillus flavus and A. parasiticus.
Several types of aflatoxin (14 or more) occur in nature, but four – aflatoxins B1, B2, G1 and G2 are particularly dangerous to humans and animals as they have been found in all major food crops. Aflatoxins are found occasionally in milk, cheese, peanuts, cottonseed, nuts, almonds, figs, spices, and a variety of other foods and feeds. Milk, eggs, and meat products are sometimes contaminated because of the animal consumption of aflatoxin contaminated feed. Cottonseed, Brazil nuts, copra, various tree nuts and pistachio nuts are the other commodities quite susceptible to the invasion of aflatoxin producing fungi. But most human exposure comes from contaminated nuts, grains and their derived products.
Fungal growth can occur on food at any point in the pre- or post-harvest stage, making it difficult to control contamination. Pre-harvest contamination with aflatoxins is mainly limited to maize, cottonseed, peanuts and tree nuts. Post-harvest contamination can be found in a variety of other crops such as coffee, rice and spices.
The formation of aflatoxins is influenced by physical, chemical and biological factors. The physical factors include temperature and moisture. The chemical factors include the composition of the air and the nature of the substrate. Biological factors are those associated with the host species.
Additionally, high temperatures and humidity favor fungal growth so countries that have these environmental conditions, namely Sub-Saharan Africa and Southeast Asia, often experience greater contamination.
Aflatoxin poisoning
