Sushi Alert– Parasites on the rise

Published: 13 Jun 2017

With food trends ever changing, the eating of raw or undercooked fish is becoming more common in the Western world. This method of procurement and consumption of food is not without risk.

There can be food safety issues with the service of some fish and shellfish, especially when serving raw. Hazards can range from allergic reactions, to the fish and shellfish containing parasites and pathogens which can lead to illness.

Recently sushi has made the headlines for all the wrong reasons. Doctors writing in the British Medical Journal Case Reports have indicated sushi's growing popularity in the West could be linked to a rise in parasitic infections.

Experts treated a 32-year-old man in Lisbon, who was found to have parasite larvae on his gut lining. He had been suffering stomach pain, vomiting and fever for a week. It was only when the man said he had recently eaten sushi that doctors suspected he might have anisakiasis.

Anisakiasis is a parasitic disease caused by anisakid nematodes (worms) that can invade the stomach wall or intestine of humans. It occurs when infected larvae are ingested from undercooked or raw fish or squid.

They added that most cases of anisakiasis to date had been reported in Japan, but warned: "However, it has been increasingly recognised in Western countries."

Atlantic salmon and sea trout caught at sea or in UK rivers are also known to be at risk of being infected with the same species of parasite, NHS Choices says.

The advice is to remove the guts of the fish, freeze it for at least four days and then cook thoroughly before eating. Suppliers of fish and shell fish must also be approved by the business.