People Who Eat Raw Salmon Could Get Tapeworm: Federal Health Study

CHICAGO (CBS) -- Scientists have found a parasite from Asian salmon in North American fish, putting those who eat raw salmon at risk of contracting a tapeworm infection.

The Japanese broad tapeworm, also known as Diphyllobothrium nihonkaiense, can grow up to 30 feet long in the human body, according to a new study in the Centers for Disease Control and Prevention's journal Emerging Infectious Diseases.

These worms were first recognized in 1986, with the first known human infection in 2008, said Dr. Roman Kuchta, a researcher at the Institute of Parasitology and the lead researcher on the report. Since then, it has been reported in about 2,000 illnesses in Japan and other parts of northeast Asia.

While the chance of contracting an infection with the tapeworm appears to be low, it does exist. Experts behind the study found that "salmon from the American and Asian Pacific coasts and elsewhere pose potential dangers for persons who eat these fish raw."

Most often, tapeworm leads to minor symptoms, if any, the CDC says. Some may suffer abdominal pain, diarrhea and weight loss. The infection can also lead to deficiency in vitamin B12 over time.

In July 2013, scientists examined 64 Alaskan-caught salmon of varying species: Chinook, coho, pink, sockeye, as well as rainbow trout. Using a molecular method, researchers found the tapeworm in the muscles of a Pacific pink salmon, close to the fish's spinal cord.

The intent of the study, researchers wrote, was "to alert parasitologists and medical doctors about the potential danger of human infection with this long tapeworm resulting from consumption of infected salmon imported (on ice) from the Pacific coast of North America and elsewhere."