Brazilian study finds parasites in 96% of sampled sushi-grade skipjack tuna
Researchers in Brazil discovered that 96% of 53 skipjack tuna specimens were contaminated with parasites, including in the muscle tissue eaten raw.
Scientists from the Federal University of Santa Catarina analyzed 53 skipjack tuna caught off Brazil and reported that 96% were infested with parasites, amounting to roughly 1,600 worms. The majority of these parasites were located in the intestines, yet a notable portion was found in the muscle tissue used for sashimi. Researchers stressed the importance of promptly removing internal organs to stop migration into edible flesh and recommended thorough cooking to avoid symptoms such as nausea, vomiting and diarrhea.
Their findings mirror a broader trend, with earlier research documenting a dramatic rise in herring-worm prevalence in raw fish over recent decades. Skipjack tuna is a globally popular species, with millions of tons harvested each year, raising concerns for international seafood safety. Some experts, however, view parasite presence as a sign of a healthy marine ecosystem despite the health risks.
Why it matters
High parasite rates in popular raw-fish species pose food-safety risks for consumers worldwide.
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