Researchers have identified a Japanese broad tapeworm in Alaskan-caught salmon.

According to a new report from the Centers for Disease Control, a Japanese broad tapeworm, Diphyllobothrium nihonkaiense, has been identified in Alaskan-caught salmon.

The Japanese Tapeworm

The identified Japanese tapeworm has been cited to be responsible for around 2,000 cases of known human infections. The vast majority of those cases are in Japan, South Korea and other surrounding regions.

The CDC report says that researchers have found this parasite in salmon that was caught in and imported from the Pacific coast of North America, and in some other regions.

In July 2013, a team of researchers examined 64 wild Alaskan salmon. They analyzed the internal organs of each fish and discovered larvae of the tapeworm, usually between 8 and 15 millimeters long.

These larvae were genetically sequenced and discovered to be the Japanese tapeworm.

The results show that four species of Pacific Salmon are known to carry the tapeworm: chum salmon, masu salmon, pink salmon and sockeye salmon.

To Worry or Not to Worry?

The CDC warns that humans who eat salmon improperly cooked are at risk of contracting the tapeworm.

They are currently alerting medical professionals about this. Because the salmon is exported on ice, unfrozen and then sold to restaurants around the world, infections are expected to occur anywhere from China to Europe, from New Zealand to Ohio, where freezing does not typically occur.

“Cooking for 145 Fahrenheit for four or five minutes will destroy the tapeworm,” said Dr. Patrick Okolo, chief of gastroenterology at Lenox Hill Hospital in New York, who was not involved in the study. “Freezing fish under certain conditions will also destroy the worm and its larvae.

The Center warns: “For more effective control of this human food-borne parasite, detection of the sources of human infection (e.g. host associations), and critical revision of the current knowledge of the distribution and transmission pattern of individual human-infecting tapeworms are needed.”