Aflatoxin poisoning — DTM&H MCQ

Correct answer: B — Aflatoxin poisoning

The correct answer is B, aflatoxin poisoning. The stem describes an outbreak of jaundice, vomiting and abdominal pain temporally linked to poor maize storage, with markedly elevated transaminases and negative viral hepatitis serology, which is the classic epidemiological and biochemical signature of acute aflatoxicosis. Aflatoxin B1, produced by Aspergillus flavus and Aspergillus parasiticus growing on damp, poorly stored maize or groundnuts, is directly hepatotoxic and causes centrilobular necrosis with very high AST/ALT, distinguishing it from viral hepatitis. This mirrors documented outbreaks such as the 2004 eastern Kenya epidemic, where contaminated homegrown maize with aflatoxin B1 levels far above the safety limit caused acute hepatic failure with negative viral panels. Prevention centres on proper drying and storage of grain and food-chain surveillance to reduce fungal contamination. Why the other options are wrong: A. Pellagra: This is a niacin (vitamin B3) deficiency disease causing dermatitis, diarrhoea and dementia, not acute hepatitis or a rapid outbreak of jaundice with transaminitis; it has no mechanistic link to grain storage toxins. C. Yellow fever outbreak: This would require a competent mosquito vector, a viraemic phase and positive serology or PCR; the stem explicitly excludes viral hepatitis markers and gives a clear food-storage exposure instead. D. Acute schistosomiasis: This (Katayama syndrome) follows freshwater exposure and causes fever, urticaria and eosinophilia weeks after cercarial penetration, not an acute maize-linked hepatotoxic outbreak. E. Ciguatera poisoning: This follows ingestion of reef fish contaminated with ciguatoxin, producing gastrointestinal and neurological symptoms (paraesthesiae, temperature reversal), not hepatocellular jaundice, and has no link to maize. Key point: A hepatotoxic outbreak clustering with poorly stored maize or groundnuts and negative viral hepatitis serology points to aflatoxin (Aspergillus flavus) poisoning.

Reference: CDC/Environmental Health Perspectives: Lewis L et al, Aflatoxin Contamination of Commercial Maize Products during an Outbreak of Acute Aflatoxicosis in Eastern and Central Kenya, 2005 (https://pmc.ncbi.nlm.nih.gov/articles/PMC1314917/); consistent with WHO food safety guidance on mycotoxins.