Bad News For Sushi Lovers: Scientists Finds Tapeworm In United States' Salmon

Bad news for sushi lovers as scientists confirms that a tapeworm known to infect salmon from the Asian Pacific is also present in fishes from United State waters.

The United State Centers for Disease Control and Prevention (CDC) noted that the parasite, known as the Japanese broad tapeworm, can grow up to 30 ft long in the human body and so many people who become infected have no symptoms, according to the CDC.

In some cases, it is accompanied by abdominal pain, weight loss, diarrhea, and can also lead to deficiency in vitamin B12. Symptoms only manifest in about 20 percent of affected persons. According to the study's lead author, Roman Kuchta, massive infection, in rare cases can cause an intestinal obstruction or gallbladder inflammation.

However, the tapeworm infection seems to be uncommon as only about 2,000 cases have been reported in humans, mostly from northeastern Asia, Kuchta says. He added that the first reported case of tapeworm infection in humans in North America was recorded in 2008, according to Health.

Kuchta and his colleagues have now found tapeworm in the wild pink salmon from the Alaskan Pacific. Although the risk of contracting the tapeworm from sushi is low, it exists, according to Dr. Amesh Adalja, a spokesman for the Infectious Diseases Society of America and a senior associate at the University of Pittsburgh's Center for Health Security.

Adalja added that there are also inherent risks when eating uncooked fish or other raw foods, like unpasteurized milk, but the risk is not limited to tapeworm infection as it includes other food borne pathogens such as bacteria, viruses and other parasites.

However, people who love sushi are advised to keep it up but it is important not to rule out the possibility of tapeworm infection. They are advised to contact their physicians if the develop any unexplainable symptoms.

The findings are based on the analysis of 64 wild salmon, from five different species, caught off the Alaskan coast. The researchers found that Samples of pink salmon harbored the Japanese broad tapeworm larvae, according to CBS News.

A tapeworm that grows to its full adult length consumes lots of vitamin B12, which can lead to a deficiency in vitamin B12 and has numerous neurological consequences according to Dr. Patrick Okolo, chief of gastroenterology at Lenox Hill Hospital in New York City.

The consequences can include numbness, balance problems, tingling, and issues with thinking and memory retention. He agrees that the tapeworm risk from raw salmon is low, but he advised doctors to consider the possibility of a tapeworm infection if a patient's deficiency in vitamin B12 cannot be otherwise explained.

He also recommends a safety measure for people who make raw fish dishes at home to freeze the fish for a few days, so as to kill any parasite.

Tapeworm infections are treatable with medication, Adalja said. Two drugs, known as "praziquantel" (Biltricide) and "niclosamide" (Niclocide), are the major drug used to combat the parasite, according to the CDC.

The scientist published their findings in the February issue of the CDC's journal Emerging Infectious Diseases.