Scientists Discover Parasites in US Salmon

Here’s some more bad news for sushi fans, scientists have discovered that a tapeworm known to infect fish found in Asia is now also in the United States.

Earlier this week, researchers found nearly 50% of sushi in Los Angeles is actually mislabeled. Researchers visited 20 sushi restaurants in L.A. from 2012 and 2015 and found that 47% of all sushi were inaccurately labeled. Then researchers found that the problem expanded to grocery stores, with fish also being mislabeled. Now, researchers have found parasites in salmon in the US.

The CDC published the study in the February issue 2017 of Emerging Infectious Diseases. Roman Kutcha from the Institute of Parasitology explained that in 2013 he examined 64 different wild Pacific salmon obtained from local fisherman. After examining the fish, researchers found Diphyllobothriasis parasitic larva inside Alaskan pink salmon. Kutcha explained that this type of salmon from North America’s Pacific coast is a source of human parasite infection. Researchers also point out that because Pacific salmon is transported unfrozen, parasites are able to survive after being transported to other parts of the world.

This is not the first time researchers discovered tapeworms in salmon. In 2009, Naoki Arizona from the University of Medicine in Kyoto, Japan found the same type of parasite was being found in urban areas in Japan and Europe. Researchers at the time explained that people who eat raw seafood, accounted for the increase in parasitic infections in humans.

Diphyllobothriasis also known as the Japanese broad tapeworm has the ability to grow up to 30 feet long once inside the human body. According to the U.S. Centers for Disease Control and Prevention, the Japanese tapeworm typically doesn’t exhibit any symptoms. However, overtime the tapeworm can lead to vitamin B12 deficiency, weight loss, and stomach pain.

According to the CDC, the best way to diagnosis Diphyllobothriasis parasite is by a microscopic identification of eggs in the stool. In turn, the parasite can be treated with several medications including Praziquantel. However, the safety of the medication has not been established for children under the age of four.