TOKYO -- A woman in Japan had a live worm removed from her tonsil several days after she consumed raw fish, according to a medical journal.
The 25-year-old anonymous patient got checked at Tokyo’s St. Luke’s International Hospital after suffering from throat pain and irritation, according to FOX 2 Now.
The woman told the physician that she had eaten an assortment of sashimi five days before her visit, according to a study published on the incident in The American Society of Tropical Medicine and Hygiene.
During her physical examination, the doctor found a live worm inside her left tonsil, the study stated. The worm was removed using a pair of tweezers and her symptoms quickly disappeared.
The worm was a little over one inch and was molting its outer skin, the study said.
It was determined that the worm was a Pseudoterranova azarasi, a type of white roundworm that can cause gastric, intestinal, ectopic and allergic disease, the study said. The specific type of worm largely infects the stomach area of whatever host it lives in and is often ingested through raw or under-cooked fish.
There have been more than 700 cases of the worm infecting people in Japan, North Pacific countries, South America and the Netherlands, according to the study.
The study also suggested that the most effective way to rid a host of the parasite is to have it physically removed, as opposed to taking an antibiotic or other pharmaceutical treatment.
All living organisms, including fish, can have parasites. Roundworms, called nematodes, are the most common parasite found in saltwater fish, such as cod, plaice, halibut, rockfish, herring, pollock, sea bass and flounder, according to Seafood Health Facts, an online resource about seafood products operated by the Delaware Sea Grant.
These types of infections are rare, but the number of cases has certainly increased due to the worldwide popularity of consuming raw fish such as sushi and sashimi, the study stated.
"Although it has likely been greatly underdiagnosed and underreported, (approximately) 60 cases of anisakidosis have been described in the United States," a 2010 study published in Clinical Infectious Diseases states.
If diners choose to eat raw fish anyway, the Food and Drug Administration says a rule of thumb is to eat fish that has been previously frozen.
Freezing fish to an internal temperature of -4 degrees Fahrenheit for at least seven days will kill parasites. Cooking seafood to an internal temperature of at least 145 degrees Fahrenheit for 15 seconds also kills parasites, the CDC says.