A parasitic tapeworm that infests Asian Pacific salmon has been found in some salmon in American waters, but the risk is extremely low.
This is a heads up for sushi or raw salmon eaters. The Japanese broad tapeworm, which infects salmon from Asian Pacific waters, has been found in wild pink salmon coming from the Alaskan Pacific.
That's the assessment of Roman Kuchta, the lead researcher of a report that was recently published in the CDC's February journal 'Emerging Infectious Diseases.'
The risk of contracting the tapeworm is extremely low. Only around 2,000 cases of humans with the parasite have been documented and most of those have been in northeast Asia. The first case in North America was recorded in 2008.
"When you're eating uncooked fish — or other raw foods, like unpasteurized milk — there is some inherent risk," said Amesh Adalja, a spokesman for the Infectious Diseases Society of America. "So, if you do develop unusual symptoms that can't be explained, you could mention to your doctor that you eat raw fish."
Most people who become infected show no symptoms, which of course suggests that there may be more instances of infestation out there than the reported numbers might indicate. But about 20 percent of people infected do exhibit signs, such as abdominal pain, diarrhea and weight loss.
A tapeworm infestation can also lead to a deficiency in vitamin B12, which, if severe enough, can lead to numbness, tingling, balance problems, and trouble with thinking and memory.
Dr. Patrick Okolo, chief of gastroenterology at Lenox Hill Hospital in New York City, suggested that if a patient's B12 deficiency cannot otherwise be explained, it might be worth looking into the possibility of a tapeworm infection, especially of the patient consumes raw salmon.
Adalja indicated that the infestation is treatable with primarily one of two drugs, praziquantel (Biltricide) and niclosamide (Niclocide).
Kuchta also said that in rare cases "massive infection" can cause an intestinal obstruction or gallbladder inflammation.
One of the creepier aspects of a tapeworm in humans is the fact that they can grow upwards of 30 feet in length.
If you do enjoy sushi or raw salmon at home, one method of killing any possible infestation is to freeze the salmon for a couple of days before consuming.
Like what you see here? You can read more great articles by David Smith at his Facebook page, Stumpjack Outdoors.
Enjoy the outdoors?
Sign up for daily stories delivered straight to your inbox.