Tapeworm infection from eating sushi is now more than ever a cause of alarm after the Fresno incident. What is really the downside of consuming raw or undercooked fish?

The recent news about a man pulling out a 5-foot tapeworm from his bottom while inside the toilet raises serious concern over the possible risks of eating raw fish. The man from Fresno claimed that his years of consuming sushi from raw salmon is the culprit for the tapeworm that resided inside his body.

Numerous reports in the past have also linked eating raw fish delicacies to tapeworm and other parasitic infections among humans

Dangers Of Eating Raw Fish

The experts have warned repeatedly that eating raw fish increases the risk of Japanese tapeworm or parasitic infection in humans.

"The risk of becoming infected with the Japanese tapeworm parasite is most prevalent when consuming raw or undercooked fish, particularly in dishes such as sushi, sashimi and ceviche," states a 2017 report of the Centers for Disease Control and Prevention.

Many fish-borne parasites can live in humans. While some parasites do not cause acute symptoms to its host, many may cause serious harm in the long run.

A specific tapeworm, the Diphyllobothrium nihonkaiense species, can survive in fish and infect humans, bears, and wolves.

The anisakid nematodes, a type of roundworm, causes parasitic infection in humans called anisakiasis, where the worm larvae invade the stomach's lining. This kind of infection may require surgery or endoscopy to remove the parasite from the human body.

Liver fluke flatworms cause opisthorchiasis, a disease that attacks and infects the liver, bile duct, and gallbladder.

Likewise, eating raw seafood contaminated with Staphylococcus aureus, Listeria, Salmonella and Vibrio parahaemolyticus also causes certain food-borne illnesses.

In the past, tapeworm infections were only widely documented in Japan. Eating or consuming of raw fish in the country is considered as part of their diet. It was only in 2008 when tapeworm infection was first reported in North America.

Last year, researchers said the Japanese tapeworm could be present in the Alaskan-caught wild salmon, increasing the risk of parasite infection in people who eat raw fish.

Best To Eat Cooked Fish

People with medical conditions such as liver disease, cancer, and immune system problems are strongly advised against consuming raw or undercooked fish.

Pregnant women, children, and elderly people are also at high risk of being infected with fish-borne parasites and food-borne illnesses. Listeria infection, although rare, may cause fetal death in pregnant women.

There are also fish species that contain high amounts of pollutants and toxic heavy metals. Mercury content is high in tilefish, king mackerel, swordfish, marlin, and tuna.

Raw fish dishes are growing in popularity in many cuisines. Some of the most common are sushi, sashimi, poke, ceviche, carpaccio, koi pla, soused herring, and gravlax.

Although these dishes may sound and taste appetizing, experts advise people to freeze and cook fish properly before eating.