Brazilian scientists found that 96% of sushi-grade tuna tested in a lab was contaminated with worms, with a total of 1,600 worms detected. The study, published in the journal Ocean and Coastal Research, analyzed 53 skipjack tuna caught locally in Brazil using powerful microscopes. The majority of the worms were concentrated in the intestines, muscle tissue, and stomach, which are often consumed by humans. Experts warn that eating raw or undercooked fish tainted with these parasites can cause gastrointestinal symptoms such as nausea, vomiting, and diarrhea.
Written by the local model on 2026-09-03,
using this article's own text rather than the other coverage of the
same event (that is the story summary below).
Story summary
96% of sushi-grade tuna tested by Brazilian scientists at the Federal University of Santa Catarina contained 1,600 worms, sparking concerns that eating raw or undercooked tuna could lead to illness. The worms were found in the intestines, muscle tissue, and stomach of the fish, which are all parts that humans typically consume. This discovery was made after analyzing 53 locally-caught skipjack tuna, a popular commercial species. While it's not uncommon for parasites to be present in fish, the sheer number of worms found in this study is alarming, highlighting the importance of sanitary inspection to prevent foodborne illnesses. The study was published in the journal Ocean and Coastal Research.
Written for “Pests Found In Tuna Sushi” on 2026-09-03,
grounded in this article and the 0 other(s) covering the same event.
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Leaning score -0.35 for article 3554 (high confidence, 1 verified quote) · logged 2026-09-03
What’s worse than finding a worm in your apple?
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What → ’ → apple
Brazilian scientists found that nearly all the tuna fish in a recent haul were contaminated by worms, sparking fears that our sashimi could be a parasite playground.
“These results highlight the importance of sanitary inspection,” warned the researchers in the a-raw-calyptic study published in the journal Ocean and Coastal Research.
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researchers → find → journal
The scientists, who hailed from the Federal University of Santa Catarina in southern Brazil, reportedly analyzed 53 locally-caught skipjack tuna — a popular commercial species — using powerful microscopes.
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who → hail → microscopes
They finding that a whopping 96 percent of the catch harbored parasites, amounting to 1,600 worms in total, Science Alert reported.
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Alert → find → total
The lion’s share of these squiggly interlopers were concentrated in the intestines followed by the muscle tissue – the portion we eat – and then the stomach while only the kidneys and hearts were untainted.
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kidneys → concentrate → tissue
While scientists weren’t surprised to find worms in fish — parasites have been infesting them since time immemorial — they were shocked at the sheer numbers and how widespread they were in the organs.
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they → find → organs
This is particularly disconcerting given skipjacks’ global popularity with 3.1 million tons of this prized eating fish caught and sold around the world in 2022.
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This → give → 2022
Scientists said this highlighted the importance of immediately removing the viscera to prevent parasites from migrating from the organs to the meat.
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this → say → meat
Unfortunately, despite meticulous examination by seafood processors and sushi chefs, these sashimi stowaways inevitably wriggle under the radar.
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stowaways → wriggle → radar
Unfortunately, finding these parasite piñatas is becoming more and more common.
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finding → find → piñatas
In 2020, University of Washington researchers found that there’s been a 283-fold spike in the amount of herring worms — which parasitize a variety of fish and squid — in raw fish between 1967 and 2017.
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which → find → 1967
In other words, we’ve gone from finding one worm per every 100 fish caught to one in every single one.
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we → go → one
Eating raw or undercooked fish tainted with these interlopers can cause wreak gastrointestinal havoc, causing symptoms including nausea, vomiting and diarrhea.
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Eating → eat → nausea
Fortunately, these effects subside when the fish-hiking parasites die in a few days.
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parasites → subside → days
Experts recommend thoroughly cooking fish to reduce the likelihood of contracting these intestinal infiltrators.
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Experts → recommend → infiltrators
Despite the illness risks, some experts believe that many parasites are an indicator of freshness, similar to how insect-ridden produce is said to signify organic provenance.
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produce → believe → provenance
“Everyone assumes that worms in your salmon is a sign that things have gone awry,” said Chelsea Wood, a parasitologist at the University of Washington.
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Wood → assume → Washington
“I see their presence as a signal that the fish on your plate came from a healthy ecosystem.”
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fish → see → ecosystem
