As this is an extremely lethal toxin, there are reports of cases of poisoning in some types of oysters and Asari (short-necked clams). The source of the Venerupin is said to be the intake of toxic dinoflagellate. This only occurs in early Spring in Nagai, Kanagawa prefecture and Lake Hamana in Shizuoka prefecture and in one instance over 100 people died. However, as there have been no incidents of poisoning since 1950, it’s still not clear if the shellfish actually become toxic or not.
In most cases, the toxic symptoms appear within one to two days and start with abdominal pain, vomiting, constipation, etc., followed by blood spots on the skin and bleeding from the mouth and nose. Liver function also significantly decreases and the patient suffers from mental derangement. They then fall into a coma and die within a few days.
