Article Text

Download PDFPDF
Rare disease
Diphyllobothrium nihonkaiense infection linked to chilled salmon consumption
  1. Taro Shimizu1,
  2. Kensuke Kinoshita2,
  3. Yasuharu Tokuda2
  1. 1Rollins School of Public Health, Emory University, Atlanta, Georgia, United States
  2. 2Department of General Internal Medicine, Tsukuba University, Mito, Japan
  1. Correspondence to Dr Taro Shimizu, shimizutaro7{at}


This is a case of a 40-year-old Japanese adult male who had acute onset watery diarrhoea with intermittent abdominal discomfort. Several days later, he found a 1 metre of tape-shaped object emerged from his anus and was eventually admitted to our hospital for further investigation. Stool examination revealed eggs of Diphyllobothrium with characteristic shape in his stool. After oral praziquantel administration, segments of proglottids were expelled from his anus. The proglottids were sent to the Infectious Disease Surveillance Centre of Japan, and DNA analysis of the proglottids proved to be those of Diphyllobothrium nihonkaiense. The patient confessed that he had an eating habit of chilled salmon. His diarrhoea and abdominal discomfort were completely diminished after 1 day of oral praziquantel administration. He was successfully discharged from the hospital a few days later admission without any complication of the disease and the side effect of treatment.

View Full Text

Statistics from


  • Competing interests None.

  • Patient consent Obtained.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.