Anisakiasis B81.0

Anisakiasis is very rarely observed in Germany (data from the Robert Koch Institute). Only a few hundred cases a year are known. Here, mainly countries are affected where raw fish is consumed. This is mainly Japan.

However, when the symptoms appear, the consumption of raw fish should be asked. Especially if no other cause can be identified. A specific serodiagnosis can be performed in various countries. Specific serodiagnosis can be carried out in various special laboratories.

In the foreground is the gastrointestinal symptomatology. About 6-12 hours after ingestion of the larvae by eating raw fish, gastroenteritis with severe abdominal pain usually occurs. Occurrence of eosinophilic granulomas in the gastrointestinal tract. More rare are extraintestinal manifestations such as acute (and chronic) urticaria and angioedema. Small bowel obstruction, ileitis and appendicitis are rarer.

The symptoms are caused by the larvae of the nematodes, which penetrate the mucous membranes of the stomach and intestines. They cause pain and inflammatory local reactions. In the further course of the disease, nodular eosinophilic granulomas are formed due to local inflammatory processes. These can cause severe disorders up to an ileus or intestinal perforation. Since humans are a false host, the nematode larvae die after 2-3 weeks. However, the symptoms may persist.

Gastroscopy, detection of nematodes in the stool.

Anisakiasis must be distinguished from the equally rare anisakis simplex allergy. The allergic symptoms can affect the skin, respiratory tract, gastrointestinal tract or circulation (up to anaphylactic shock).

There is no effective antiparasitic therapy. There are indications for a therapy with the anthelmintics albendazole or tiabendazole. Symptomatic granulomas in the abdomen must be removed surgically if necessary. However, the disease often heals on its own.

Because of the limited therapeutic options, prophylaxis is of particular importance. Here it is important to know: The larvae die at temperatures above 60 °C or below -20 °C. They also do not survive brine. Therefore, crabs or sea fish (herring, mackerel) should only be eaten after sufficient previous heating or safe preservation (marinating, smoking). Deep freezing before further processing is also an effective preventive measure.

There is no obligation to report.

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