Food poisoning due to methamidophos-contaminated vegetables

Background: Organophosphate poisoning is well known for its characteristic symptoms and signs, but food poisoning caused by pesticide-contaminated foo d is seldom reported. Case Report: We report three incidents of food poison ing that resulted from exposure to the organophosphate insecticide methamid ophos in vegetables. These outbreaks caused a cholinergic syndrome in 4 pat ients. The cholinergic over-activity led its to suspect organophosphate foo d poisoning. All patients recovered well following appropriate therapy. The clinical diagnosis of organophosphate poisoning was confirmed by reduced l evels of erythrocytes and plasma cholinesterase and the presence of methami dophos in the vegetable leftovers. The implicated vegetables and levels of methamidophos were: lpomoea batatas 255 ppm, Gynura bicolor 110 ppm, and re d cabbage 26.3 ppm. Since methamidophos is normally applied to vegetables d uring planting, improper selection and/or overuse of pesticide or improper harvest times may explain the occurrence of these high residue levels of me thamidophos.