Scientists have confirmed that salmons caught in U.S. waters are infested with Japanese tapeworms. The parasite was thought to infest only fish from the waters of Asia Pacific but now there are studies that show that these are also present in wild pink salmon coming from the Alaskan Pacific.

The U.S. Centers for Disease Control and Prevention said that people who have become infected with the tapeworm have no symptoms, according to CBS News. Japanese broad tapeworm can grow up to a length of 30 feet inside the human body and a person with tapeworm can have symptoms ranging from abdominal pain, weight loss, diarrhea and overtime, vitamin B12 deficiency.

Roman Kuchta, lead author of the research from the Czech Academy of Sciences in the Czech Republic said that infection with tapeworm is actually uncommon. Only 2,000 cases have been reported in humans and these are mostly in northeastern Asia. The first case of tapeworm infestation in North America was in 2008. Kuchta's team's research is published in the February issue of Emerging Infectious Diseases of the CDC.

Experts are now worried that people who love to eat raw fish might not be willing to give up their preferences. They advise people to visit their doctor should they develop unusual symptoms and mention that they ate raw fish. Tapeworm infestation is treatable but in rare cases, tapeworms could multiply and cause intestinal obstruction.

CNN also reported that the only way to avoid getting infected with tapeworm is to be cautious about what to eat. Instead of completely avoiding raw fish, choose fish that has been adequately frozen or cooked. The CDC advised that cooking for four to five minutes at 145 Fahrenheit can destroy tapeworms. Freezing can also destroy the worm and its eggs.

People who suspect that they have tapeworms may collect a sample of their stool and then sent it to a lab for testing. A doctor can quickly identify the presence of tapeworms and the infection may be treated effectively.