Anisakis is the number one cause of food poisoning in Japan. Anisakis larvae parasitize fish and shellfish such as mackerel.

When it enters the human body, it pierces the stomach and intestines, causing severe abdominal pain and vomiting. The number of patients per year is estimated to be as high as 10,10. An isakis allergy often develops in people who have many opportunities to touch sea fish, such as chefs, people who fish and do marine sports, and people who prefer sushi.