Sushi Health Warning As Doctors Report Rise In Parasitic Infections

Doctors have issued a serious warning about sushi's recent spike in popularity after a man in Lisbon, Portugal, was violently sickened by the Japanese delicacy.

Writing in the journal BMJ Case Reports, the Lisbon doctors who treated him have warned clinicians to consider the condition in patients with pain, nausea, vomiting and other complications, such as bowel obstruction and bleeding, who have recently eaten sushi. When doctors performed an endoscopy on the man, they found the larvae of a worm-like parasite attached to the gut lining.

Sushi lovers are being warned of the dangers of ingesting parasites from raw and undercooked fish, a study revealed on Friday.

After the parasite was removed from his gut, the patient's symptoms immediately began to clear.

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.

They inserted an endoscope - a long tube with a camera on the end - through his mouth into his stomach.

The study mentions that most cases of this condition have been diagnosed in Japan, but that it was becoming more recognised elsewhere.

Two views of the parasite, seen here firmly attached to an area of the patient's upper gastrointestinal tract. He was also vomiting and had a fever. On laboratory analysis, it was proved that the larva belonged to the Anisakis species.

This one's just best left described by the CDC: "Some people experience a tingling sensation after or while eating raw or undercooked fish or squid".

But they wrote: 'Owing to changes in food habits, anisakiasis is a growing disease in Western countries'.

Although it is generally considered safe to eat some types of raw fish if it is very fresh, experts said sushi actually carries an unseen hazard.

Cases of anisakiasis are more rare in Western countries due to the fact that most dietary fish is cooked, which kills the worms.

"For example, freezing fish to the appropriate temperature and for the appropriate duration can kill parasites", Rowland said.

  • Aubrey Nash