The unsavoury truth about your sushi: Scientists discover 96% of tuna are infected with parasitic worms

If you were looking forward to digging into a platter of sushi this evening, you might want to rethink your options.A disgusting study has revealed how tuna are riddled with parasitic worms. Scientists from the Federal University of Santa Catarina in Brazil collected 53 locally caught fish, and dissected them for worms. A whopping 96 per cent of the fish tested contained worms, with more than 1,600 parasites collected in total. Worryingly, one of the types of worm, Anisakis, is known to harm human health if ingested.'The nematode can penetrate the human intestinal wall, causing an acute, transient infection characterized by symptoms such as abdominal pain, vomiting, nausea, and/or diarrhea,' the researchers warned. Scientists from the Federal University of Santa Catarina in Brazil collected 53 locally caught fish, and dissected them for worms. A whopping 96 per cent of the fish tested contained worms, with more than 1,600 parasites collected in totalIn the study, the team focused on Katsuwonus pelamis, which is also known as skipjack tuna.'Katsuwonus pelamis is a fish resource of high economic value and widely used in the fish processing industry, mainly for canned products,' they explained in their study, published in Ocean and Coastal Research.'This study aimed to identify the parasitic fauna of by morphological methods, to analyze the potential impact on industry and consumers.'After collecting the fish, the researchers used a technique called Scanning Electron Microscopy to inspect them for parasites. The results revealed two genera of parasites in 96 per cent of the fish – Anisakis and Trypanorhyncha. These worms were mostly found in the fishes' intestines, muscle tissues, and stomachs, with 596, 441, and 408 parasites, respectively.Worryingly, the researchers say that consuming these worms can be extremely dangerous to humans. What's more, cooking the fish may not be enough to protect you. The results revealed two genera of parasites in 96 per cent of the fish – Anisakis and Trypanorhyncha What are the most commonly faked fish swapped with? Tuna: Escolar or cheaper tuna speciesSalmon: Less sustainable populations or rainbow troutYellowtail: Escolar or Asian catfishRed snapper: TilapiaTiger prawns: Whiteleg shrimpCuttlefish: Squid or OctopusEel: Critically endangered European eel 'Cooking and/or freezing seafood may not be sufficient to prevent hypersensitivity reactions,' they warned. 'Thermostable allergens have been detected in extracts, raising questions about the safety of consuming these parasites in cooked fish.'The study comes shortly after scientists warned that tuna, salmon, and even prawns are being swapped out for cheaper alternatives and mislabelled as a premium product.Dr Marine Cusa, a marine biologist and policy expert from the Technical University of Denmark, told the Daily Mail: 'Because mislabelling rates depend on the species, if consumers want to avoid mislabelling then they should avoid certain species and prioritize others.'White fish like cod, haddock, and saithe in general are rarely mislabelled in Europe apart from their geographical origin.'But tuna, swordfish, groupers, snappers, sharks, rays, have a higher species mislabelling risk.'