[5][6] Aflatoxin B1 is a common contaminant in a variety of foods including peanuts, cottonseed meal, corn, and other grains;[7] as well as animal feeds.

In animal studies, pathological lesions associated with aflatoxin B1 intoxication include reduction in weight of liver,[20] vacuolation of hepatocytes,[21] and hepatic carcinoma.

[22] Other liver lesions include enlargement of hepatic cells, fatty infiltration, necrosis, hemorrhage, fibrosis, regeneration of nodules, and bile duct proliferation/hyperplasia.

The mold lives in soil, surviving off dead plant and animal matter, but spreads through the air via airborne conidia.

[24] This fungus grows in long branched hyphae and is capable of surviving on numerous food sources including corn and peanuts.

[24] While toxicity of its products, aflatoxins, are explored throughout this article, Aspergillus flavus itself also exerts pathogenic effects through aspergillosis, or infection with the mold.

The next two steps in the biosynthetic pathway is the methylation by S-adenosyl methionine (SAM) of the two hydroxyl groups on the xanthone part of demethysterigmatocystin by two different methyltransferases, OmtB and OmtA.

In the final steps there is an oxidative cleavage of the aromatic ring and loss of one carbon in O-methylsterigmatocystin, which is catalyzed by OrdA, an oxidoreductase.

Aflatoxin B1 is a potent genotoxic hepatocarcinogen with its exposure strongly linked to the development of hepatocellular carcinoma, liver tumors, especially given co-infection with hepatitis B virus.

Up to 44% of hepatocellular carcinomas in regions with high aflatoxin exposure bear a GC → TA transversion at codon 249 of p53, a characteristic mutation seen with this toxin.

For instance, biological decontamination involving the use of a single bacterial species, Flavobacterium aurantiacum has been used to remove aflatoxin B1 from peanuts and corn.

[53][54] Twelve patients died of acute aflatoxin poisoning in several hospitals in the Machakos district of Kenya in 1981 following the consumption of contaminated maize.

[55] Following outbreaks of aflatoxin contamination in maize reaching 4,400 ppb in the spring of 2004, 125 individuals in Kenya died of acute hepatic failure while some 317 cases in total were reported.