"Shocking Discovery for Tuna Sashimi Lovers: 1,600 Parasites Found Crawling Inside"

Penetrating Deep into Organs and Muscle
Survey Conducted on 53 Skipjack Tunas from Southern Brazil

A significant number of Brazilian skipjack tunas were found to be heavily infested with Anisakis and other parasites. Notably, a large quantity of parasites was detected even in the flesh, not just the internal organs, raising particular concern for those consuming raw fish.

Lifting a slice of tuna sashimi from a kaisendon bowl. Getty Images

Parasites Penetrating Even Tuna Flesh

On September 3 (local time), The New York Post reported that researchers from the Federal University of Santa Catarina, Brazil, announced through the international journal 'Marine and Coastal Research' that after examining 53 skipjack tunas caught locally, parasites such as Anisakis (commonly known as "whale worm") were found in as many as 96% of the specimens.

Inspected tuna (A) and internal organs (B), infected tissues (C, D, E). Photo by New York Post

The total number of parasites identified in this investigation reached approximately 1,600. While the highest concentration was found in the tuna's intestines (596 cases), a substantial number was also detected in the flesh, which is typically consumed as sashimi (441 cases), as well as in the stomach (408 cases). The research team stated, "Aside from the tuna's kidneys and heart, virtually almost every part is infected with parasites."

The skipjack tuna is a popular species, with annual global catches reaching 3 million tons, and is widely consumed in forms such as tuna sashimi and canned tuna. While the discovery of parasites in fish is not uncommon, it is unusual to see such a high infection rate within a single species.

Difficult to Detect with Naked Eye... 'Freezing or Cooking' Recommended

Eating raw fish containing live parasitic larvae can cause anisakiasis, a disease where the larvae penetrate the stomach wall, leading to severe abdominal pain and vomiting. The research team emphasized, "In order to prevent parasites from migrating from the intestines to the flesh, it is crucial to remove the intestines from the tuna immediately after capture, ensuring a rapid distribution process."

Photo for illustrative purposes only, not related to specific content. Getty Images

However, even after passing through inspection during the processing stage, it is practically impossible to completely remove fine parasites. In fact, research from the University of Washington revealed that parasitic worms in raw fish have surged hundreds of times over the past several decades.

Experts advised, "Since it is difficult to perfectly identify larvae deeply embedded in the muscle with the naked eye, it is safest to thoroughly freeze the fish at below minus 20 degrees Celsius before consumption, or to cook it at above 60 degrees Celsius for at least one minute until the center is fully cooked."

Even in Cold Weather, No Relief from 'Whale Worm'

Tuna is being dismantled and prepared. Shutterstock

It is commonly believed that parasites are only found during summer, but in the case of Anisakis, they can also be discovered in winter, so there is no guarantee of safety during colder months. Particularly in Korea, between July (when seawater temperatures are high) and October (when the influx of warm currents intensifies), species such as squid and conger eel are frequently infected with Anisakis.

Anisakis is the most representative fish parasite. Its eggs drift in the water and are consumed by shrimp, which are then eaten by mackerel and other fish, ultimately reaching whales through the food chain—hence the name "whale worm." If raw fish infected with Anisakis is consumed before the parasite reaches its final host, the whale, humans can also become infected.

Roundworms cannot reproduce inside the human body due to the high acidity of human gastric juices. However, Anisakis can penetrate the stomach wall, resulting in abdominal pain, vomiting, and stomach cramps. A healthcare professional warned, "If infected with Anisakis, typical anthelmintics may be ineffective and symptoms can persist for a long time. If the pain is severe, endoscopic removal of the worms may be necessary."

This content was produced with the assistance of AI translation services.