Doctors found a worm over an inch long inside a woman's tonsil after she ate sashimi
- A 25 year-old woman in Tokyo went to the hospital complaining she'd had a sore throat for five days after eating sashimi. Doctors found a black worm over an inch long inside her tonsil.
- Experts identified the worm as Pseudoterranova azarasi, a type of parasitic roundworm that can infect humans who consume raw or undercooked ocean fish, including sushi and sashimi.
- These parasites typically infect the stomach, but there has been at least one previous case of a patient coughing up parasitic larvae from an infection.
When a 25 year-old woman in Tokyo went to the hospital with a sore throat, doctors quickly saw the the cause of the problem — peering into the woman's mouth, a small, black, moving shape was visible at the back of her throat.
Closer examination showed the critter was a parasitic roundworm called Pseudoterranova azarasi, more than an inch long, inside the woman's tonsil.
The patient reported that she had been suffering from throat pain and irritation for five days, which started after she had consumed "assorted sashimi," a raw fish dish.
She quickly recovered after medical staff removed the worm with tweezers, according to the case study published July 8 in the American Journal of Tropical Medicine and Hygiene.
A photo included in the case report shows the worm was about 38 millimeters (1.5 inches) long and a millimeter wide.
The study's authors, from St. Luke's International Hospital in Tokyo, noted that the parasite is uncommon, but can infect humans who consume raw or uncooked fish, including sushi and sashimi.
The parasite, and others in the Pseudoterranova genus, can infect the throat area, causing pain, a tingling sensation, and a cough.
In another case study from Chile, three people diagnosed with the parasites experienced "tingling throat syndrome", including coughing and retching, after eating ceviche, a raw seafood dish. All three coughed up the parasites without further complications, according to the case study.
More commonly, Pseudoterranova worms infects the stomach, causing abdominal pain. It has to be removed endoscopically in that case, but patients have been reported to occasionally vomit up the worms, as was the case for one woman in Japan in 2008.
These types of parasite infections typically occur in coastal areas where eating raw fish or squid is common. Although it's more common in Japan, where sushi is popular, most infections occur at home, not at restaurants, since quality sushi chefs are experts at identifying parasites.
Cooking fish or squid thoroughly, or freezing any raw fish before you eat it, however, will kill these and any other possible stowaways.
Read more:
A woman pulled a half-inch-long worm out of her eyeball after a trail run, and then found 3 more