Aflatoxicosis drawing attention due to the recent outbreak in Kenya
Moulds are known to cause allergic disorders, infections, and mycotoxicosis in humans. Mycotoxicosis develops due to the naturally occurring toxic metabolites produced by some fungal species. One of these mycotoxins,
aflatoxin is known to be produced primarily by strains of
Aspergillus flavus and
Aspergillus parasiticus. Aflatoxins are of 4 major types; B1, B2, G1, G2, aflatoxin B1 being the most toxic one, and two additional metabolic products, M1 and M2.
The existence of the fungus responsible for aflatoxin production does not always indicate the existence of the toxin. It just indicates the potential for toxin production.
Aflatoxins are ingested via consumption of grains contaminated with fungi producing the toxin due to the poor and unfavorable harvesting, storage or transportation conditions. Thus, the commodities are susceptible to fungal invasion and related aflatoxin production during preharvest, storage, and/or processing.
Aflatoxins may cause acute mycotoxicosis and sudden death following their ingestion in large amounts over a short period. Acute mycotoxicosis was first defined in 1960 in England following the death of more than 100 000 young turkeys and termed as "Turkey X disease".
The signs and symptoms of acute aflatoxicosis in humans include malaise, vomiting, abdominal pain, pulmonary edema, convulsions, and subsequent coma and death with cerebral edema and fatty involvement of the liver, kidneys, and heart. A recent outbreak of acute aflatoxicosis was reported by May 2004 where
over 90 cases and more than 50 deaths occurred in three Kenyan districts among people who consumed contaminated grain.
Ingestion of small amounts of aflatoxins over a longer period, on the other hand, may lead to development of hepatocellular carcinoma. In 1988, aflatoxin B1 was included in the list of human carcinogens by IARC.
To prevent contamination of grains with aflatoxins, harvesting should be done when the grains are completely dry and the storage should be carried out in well-ventilated and dry stores.
