A woman who thought her sore throat was the onset of tonsillitis discovered that she had a 38mm worm living in her glands.
The 25-year-old unnamed patient sort medical advice in Japan after suffering from symptoms for five days, the American Journal of Tropical Medicine and Hygiene reported.
Doctors at St Luke’s International Hospital in Tokyo discovered the woman had recently eaten the raw fish dish sashimi.
After a physical examination, they found a "black moving worm in the left palatine tonsil".
It was removed using tweezers and the 1mm wide worm was identified as a nematode roundworm, one of several parasites that can infect people who eat raw fish.
When it was extracted it was "fourth-stage larva" and medics believe it was consumed while in the third phase of its growth cycle.
According to the journal, the patient felt much better once the worm was removed.
"A 25-year-old woman presented with a five-day history of left pharyngeal pain and irritation after consuming assorted sashimi," it said.
"Physical examination identified a black moving worm in the left palatine tonsil. Her blood test results were normal.
"Symptoms rapidly improved after removing the worm using tweezers."
The study said due to the popularity of sushi and sashimi the number of reported worm infestations in humans is on the rise.
