I used to think that sushi was just a trend, but more and more people have turned into not only people who like sushi, but people who love it.
But those people should beware of a new parasite called Anisakiasis.
Anisakidosis, formerly known as anisakiasis or anisakiosis, and also called herring worm disease, is a parasitic infection. It is caused by eating raw or undercooked fish or seafood infected with small anisakis worms.
Symptoms include:
– Severe abdominal pain
– Nausea and vomiting
– Diarrhea
And in rare cases, it can be fatal.
Anisakiasis is on the rise in Western countries where eating sushi and other raw or undercooked fish and seafood dishes has gained popularity
Although the anisakis parasite can live as a larva for several weeks in a human stomach, it will die before developing into an adult. But before it dies, it produces an inflamed mass in the esophagus, stomach or intestine.
Untreated gastric disease can lead to chronic, ulcer-like symptoms lasting for weeks to months.
Though treatment is not always necessary, removal by endoscopy may be necessary to alleviate symptoms. No specific drug has been identified to kill the live parasites.
There are other ways of getting rid of the worm.
“Some people experience a tingling sensation after or while eating raw or undercooked fish or squid. This is actually the worm moving in the mouth or throat,” reads the CDC website. In such cases, it is possible to cough up the worm or remove it by hand. Sometimes, vomiting expels the worm.
To help reduce the risk of illness caused by eating fish or squid, the Food and Drug Administration has food safety programs and hazard reduction procedures (PDF) that distributors of fish and squid are expected to follow.
“For example, freezing fish to the appropriate temperature and for the appropriate duration can kill parasites,” Rowland said. The European Union follows similar practices, according to Carmo.
All raw fish can have parasites, but not all raw fish does—especially when you’re eating at…
…a well-established sushi restaurant. Why? That fish you’re eating was flash frozen solid at a temperature of -35°F and stored that way in a commercial freezer for at least 15 hours to kill whatever parasites happened to be in it.
Your favorite sushi joint also probably buys their fish from a seafood processor, which inspects the fish before it’s sold. Using a process called “candling,” they shine light through the fillets to look for any abnormalities, including bones. Then they either remove them or discard the fish. Many seafood processors probably get a lot of their product from fish farms, which is less likely to be riddled with worms. Multiple studies have found that fish from hatcheries have far fewer incidents of parasites, while wild-caught fish can have a very high rate of infection.
So what can you do?
Do a little research: Find reputable sushi restaurants and ask them where they get their fish. Is the seafood processor known for quality? Is the fish the restaurant serves farmed or wild-caught? Do they freeze their fish according to FDA regulations? They’ll likely be more than happy to tell you the great lengths they go for quality food. Remember, sushi chefs are trained for years to deliver you delicious fish that’s safe to eat. If they don’t, they go out of business.
Freeze and candle your own fish: If you’re preparing sushi or sashimi at home, you’ll have to be patient. You should buy thinly-sliced “sashimi-grade” fish at a reputable market, candle it, and pop it in the freezer for a whole week since it can only get to about -4°F. At that temp, it takes a lot longer to kill everything off. It was probably already flash frozen, but better safe than sorry.