Tips to help you avoid tapeworms

Follow these food safety tips to avoid tapeworms and other parasites.

February 19, 2018 - Author: Michelle Jarvie, Michigan State University Extension

Earlier this year, a California man found that he had a 5 and a half foot long tapeworm in his gut. While quite alarming, the incidence of acquiring a tapeworm in the U.S., while possibly underestimated, is rare. Tapeworms are flatworm parasites that take up residence in the intestines of humans and other animals. Most tapeworm infections in the U.S. come from beef or pork, while this particular case was probably a Japanese broad fish tapeworm. The broad fish tapeworm, Diphyllobothrium spp., is most commonly associated with salmon species in the Pacific Ocean, but have also been found in pike, walleye and yellow perch in central Canada, northern Minnesota, and Michigan. 
So how is it that a person gets to have a 5-foot long tapeworm inside them you ask? In this case, most likely from eating raw fish, as the man admitted to eating sushi daily. Larvae of the tapeworm can reside in the tissues of the fish, then when swallowed, latch on to the intestinal wall of the host, where it absorbs food through its skin, and grows. The Japanese broad fish produces few to no symptoms, thus allowing the worm to grow without the human host knowing. Depending on the species, tapeworms can grow to over 82 feet long. 
Here are a few tips to help you avoid tapeworms:
  • Avoid eating raw or undercooked fish (and meat and poultry for that matter). Fish should be cooked to an internal temperature of 145 degrees Fahrenheit.
  • If eating sushi or ceviche, make sure it is from a reputable restaurant that takes the proper precautions. How do you know? Ask before ordering.
  • Fresh fish should be put on ice immediately after catching, and should be frozen at -4 F for at least 7 days before used in raw preparations. Note that most home freezers only get to zero degrees, so using fresh caught fish is not advised for raw or undercooked preparations.
For further information about avoiding food and water-borne parasites, contact your local Michigan State University Extension office or visit:

Tags: food & health, msu extension, safe food & water

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