Worm found in tonsil of Japanese woman who had a sore throat

Almost 4cm-long nematode roundworm is thought to have come from raw fish

An unpleasant sensation at the back of the throat can be a sign that a cold is on the way. But for one Tokyo woman, the cause of the pain was not a sniffle but a live worm that had lodged itself inside one of her tonsils.

Doctors at St Luke’s International hospital in the Japanese capital removed the long black worm with tweezers after the patient had complained of throat pain and irritation, according to a case study published in the American Journal of Tropical Medicine and Hygiene.

The worm, which was 38mm long and 1mm wide, was still alive after being retrieved from the woman’s left tonsil, the journal said, adding that her “symptoms rapidly improved” after the procedure.

The worm was identified as a nematode roundworm - one of several parasites that can infect people who eat raw fish or meat.


The 25-year-old patient confirmed that she had eaten assorted sashimi five days before the worm was removed.

According to the journal, doctors said the worm was a fourth-stage larva of the worm, adding that the infection had been caused by its younger incarnation as a third-stage larva that was present in her sashimi dish.

The unfortunate diner is not alone. The authors of the study said the number of reported cases had “markedly increased worldwide” due to the growing popularity of sushi and sashimi.

Similar infections are sometimes caused by raw or undercooked meat. Two years ago, a 34-year-old Japanese man became infected by roundworm parasites after eating seared chicken sashimi. He made a full recovery, according to the British Medical Journal. – Guardian News and Media