Anisakis: what symptoms does it cause?

Nausea and severe abdominal cramps: This could be an infection caused by anisakis, a worm found in raw or undercooked fish.

Severe abdominal pain, nausea and vomiting. If we have consumed raw or undercooked fish at the origin of the disorders there may be anisakiosis.

It is an infection of the gastrointestinal tract caused, in fact, by the ingestion of raw or cooked fish products not sufficiently contained larvae of anisakis, a parasitic worm.

That’s why, even more than freshness, to enjoy sushi, tartare, carpaccio and marinated fish, you have to be sure not to take risks. This parasite settles inside fish such as sardines, herring, sea bass, cod and squid, all products often present on our tables.

What are the symptoms

Symptoms can occur from one hour to two weeks after ingestion of infected food.

If they are not excreted within the next 48 hours, the larvae of the parasite can penetrate the gastric mucosa causing severe abdominal pain, accompanied by nausea and vomiting.

In severe cases, infection caused by anisakis can lead to obstruction of the small intestine.

How to delete it

In case of suspected anisakiosis, you should seek medical attention. To detect anisakis uses the endoscope, a fiber-optic device that allows the specialist to examine the inside of the stomach. One end of the endoscope is equipped with a small mechanical forceps that can be used to remove the parasite.

Another solution to detect anisakis is radiography.

If the worm has nested in the walls of the digestive system, it may be necessary to remove it with surgery.

In order not to take risks

Proper food controls are therefore important. To avoid the risk of anisakiosis many countries oblige by law to freeze fish intended for raw consumption in advance, through the slaughter process.

If, on the other hand, you prefer to prepare the fish at home, to eliminate the risk of anisakis it is essential to cook or freeze the fish at appropriate temperatures for a sufficiently long time, equal to at least 96 hours. Among household freezers only three- or four-star ones are able to reach the required temperature. One- or two-star freezers reach too low temperatures.

To eradicate the parasite, however, neither marinating, salting nor smoking are effective.

As for cooking, the effectiveness in preventing the onset of anisakiosis depends on the duration and temperature. In particular, the EFS (European Food Safety Authority) suggests bringing the innermost part of the fish to a temperature above 60 ° C for at least one minute. To achieve this result it is necessary to cook the fish for a longer time and at a higher temperature. With these precautions you can be sure to taste the fish without unpleasant surprises.