Abstract

At the instance of the Chief Inspectorate for Health Protection, an emergency investigation was carried out, in cooperation with the State Institute for Quality Control of Agricultural Products (RIKILT), of the toxicity of sea-snails offered for consumption as whelks (Buccinum undatum). The whelks were thought to be associated with three cases of possible Paralytic Shellfish Poisoning (PSP) at Weert. The toxicity of 5 extracts, prepared and submitted to chemical analysis at the RIKILT, was tested in a mouse-bioassay according tot the official method of the Associated of Official Analytical Chemists. In one of the extracts toxicity was noticed, corresponding to ca. 35-40 mug saxitoxin- equivalents per 100 g shellfish meat. The other extracts tested in the mouse-bioassay were not lethal. The day after the toxicity experiment it became known that the suspected lot of shellfish contained "red" whelks (Neptunea antiqua) in addition to whelks. Red whelks naturally contain the poisonous substance tetramine. Consumption of these red whelks might have caused the observed intoxications. A second toxicity-experiment with mice was carried out, directed towards differences in symptoms caused by saxitoxin (one of the PSP) and the positive extract. The results of the latter experiment strengthened the assumption that tetramine rather then PSP had caused the shellfish poisoning.