Study Claims A Dramatic Increase Of Parasitic Worms In Raw Fish

People who eat forms of raw fish such as sashimi or nigiri should be aware of a new study that has been published by the University of Washington. The study looked into the significant increase in the type of parasitic worm that can be transmitted to humans who eat raw, undercooked seafood. According to the study, there has been a 283-fold increase in the abundance of a parasitic worm known as Anisakis or the herring worm since the 1970s.

The massively increase abundance of this particular parasitic worm could have significant health implications for both humans and marine animals that could eat the worm without knowing it. According to the researchers, there have been thousands of papers that looked at the abundance of the parasitic worm in particular places at particular times. Still, their study is the first to combine the results of those papers to investigate how the global abundance of the parasitic worm has changed over time.

The herring worms can be found in a variety of marine fish and squid species. The worms invade the intestinal wall if humans eat them causing symptoms that mimic those of food poisoning. The symptoms include nausea, vomiting, and diarrhea. In most cases, the parasite dies after a few days, and the symptoms disappear.

Since the symptoms of the parasitic infestation mimic those of food poisoning, the disease, known as anisakiasis, is rarely diagnosed. The parasitic worms hatch the ocean in first and infect small crustaceans such as shrimp. Small fish later eat the infected crustaceans, and the worms transfer into the fish, and the process continues as larger fish eat the smaller fish that are infected.

Humans are infected when they eat fish that contains the worms, but the worms are unable to reproduce or live more than a few days in the human intestinal tract. The worms can persist in marine mammals. The researchers say that seafood processors and sushi chefs can spot the worms and pick them out before they reach the store or restaurant, but some worms are missed. The worms can be up to two centimeters in length. Researchers recommend cutting the sushi in half to check for worms before it's consumed.