Anisakiasis - Anisakiasis

Japanese: アニサキス症 - アニサキスしょう（英語表記）Anisakiasis

What kind of infection is it?

Anisakiasis is also a type of canine heartworm disease, canine roundworm disease, Gnathostomiasis ( Student ) Like other larval migrans diseases, it is one of the causes of larval migrans.

Anisakis is a type of roundworm, and adult worms live in the stomachs of whales and dolphins. The larvae live on the surface of the internal organs and in the muscles of squid, mackerel, horse mackerel, sardines, etc., and you can sometimes see the larvae coiled up on the surface of the internal organs (liver) of commercially available mackerel.

Humans become infected by eating these raw foods, and the 2-3 cm long larvae burrow into the human stomach or intestinal wall and cause symptoms. There are gastric anisakiasis and intestinal anisakiasis.

Anisakiasis is more common during the colder months of the year and can be considered a type of winter food poisoning. If a doctor diagnoses food poisoning caused by Anisakiasis, they are required to report the case to the nearest public health center within 24 hours.

How symptoms manifest

Three to four hours after eating fresh marine fish, you may suddenly experience severe abdominal pain, nausea, and vomiting. The abdominal pain may last for more than half a day, or even up to a week, and in this case it is believed that worms have invaded the intestines rather than the stomach.

Some people may develop hives-like rashes and itching, which are thought to be an allergic reaction to Anisakis. In fact, when people with so-called mackerel allergies were investigated, it was reported that the cause was not mackerel but Anisakis.

Testing and diagnosis

In the case of gastric anisakiasis, the worms can be identified and removed with an endoscope, but in the case of intestinal anisakiasis, it is difficult to find the worms, so the small intestine is examined with an X-ray or ultrasound.

In rare cases, when worms penetrate the abdominal or thoracic cavity or other organs and cause symptoms similar to those of dog ascariasis, antibody tests can be useful.

Treatment methods

In the case of gastric anisakiasis, the pain disappears as soon as the worm is removed with an endoscope. However, since anisakiasis dies in the human body within about a week, even if the worm cannot be removed, it can be cured with just symptomatic treatment.

However, if the worms are outside the intestinal tract and causing symptoms, Anthelmintics ( English: ) (Mebendazole) is taken orally.

What to do if you notice an illness

Symptoms usually occur in the middle of the night. If you suddenly experience stomach pain 3 to 4 hours after eating fresh marine fish, please visit a clinic specializing in gastroenterology or a general hospital with a gastroenterologist on duty.

When the condition becomes severe, it is difficult to distinguish it from other emergency illnesses, so it is recommended that you visit a general hospital with an endoscopist and gastroenterologist.

Haruhiko Maruyama

Source: Houken “Sixth Edition Family Medicine Encyclopedia” Information about the Sixth Edition Family Medicine Encyclopedia

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