Sushi warning after man gets parasitic disease

The growing popularity of sushi in Western countries could be putting people's health at risk, experts warn.

Writing in the British journal BMJ Case Reports, researchers based in Lisbon, Portugal, found a healthy 32-year-old man who became violently ill after eating raw fish.

During an interview, the man said he had recently eaten sushi.

Anisakiasis is caused by worm parasites of the species Anisakis, which are often transmitted by consuming raw or undercooked fish or seafood.

Although the anisakis parasite can live as a larva for several weeks in a human stomach, it will die before developing into an adult.

After the larva was removed with a special kind of net, the man's "symptoms cleared up straight away", a team from a Lisbon hospital reported.

The doctors note that the condition, known as anisakiasis, is caused by eating undercooked or raw fish or seafood that has been contaminated: indeed, questioning of the patient revealed that he had recently eaten sushi.

It occurs when infected larvae are ingested from undercooked or raw fish or squid.


The man's condition immediately improved after the doctors found the larvae during an endoscopy and removed it.

In the past most cases have typically been found in Japan, where raw fish is a common dish.

Patients can have other symptoms too, including nausea, digestive bleeding, bowel obstruction, inflammation of the abdomen and allergic symptoms including itching and anaphalaxis, a severe and life-threatening reaction, according to the U.S. Centers for Disease Control and Prevention.

Two views of the parasite, seen here firmly attached to an area of the patient's upper gastrointestinal tract.

They added that most cases of anisakiasis to date had been reported in Japan.

The number of reports of anisakis infection, which is accompanied by sharp abdominal pain, jumped to 124 in 2016 from six in 2007, leading the ministry to urge people to either heat or freeze seafood and examine it thoroughly for signs of the parasite before eating.

"If you do choose to make your own sushi from fish at home, ensure you follow a reputable recipe", the Food Standard Agency stated, per The Guardian.

  • Sylvester Abbott