First Occurrence of a Food Poisoning Incident Due to Ingestion of Takifugu oblongus, Along with a Toxicological Report on Three Marine Puffer Species in Bangladesh

On November 16, 1998 a food poisoning incident due to ingestion of roe of Takifugu oblongus occurred in Bangladesh, affecting 8 people inclusive of 5 deaths. Their symptoms resembled those caused by tetrodotoxin (TTX) or paralytic shellfish poison (PSP). Immediately after the incident, twenty-two specimens of T. oblongus were collected from the seashore adjacent to the concerned poisoning area and their anatomical distribution of toxicity was determined. They showed a high level of toxicity in the ovary (24.5-323.8MU/g), though the toxicity levels of the other tissues, skin, muscle, liver, testis, and the viscera (except liver), were relatively low (<2-21.3MU/g). In contrast, a total of 336 specimens of three marine puffers, T. oblongus, Lagocephalus wheeleri and L. lunaris, which were collected on a regular sampling basis from Bangladesh, showed very low toxicity of less than 10MU/g in all or most tissues including gonad. The toxin partially purified from the T. oblongus specimens, as well as from the other two species, was indistinguishable from TTX in HPLC analysis. From this result and the symptoms of the victims, the causative agent in the above incident was assumed to be TTX.