Fish used in sushi and other marine life contain 283 times more parasites than they did in the 1960s, according to a review published in Global Change Biology. Researchers reviewed the literature on the prevalence of parasitic roundworms, Anisakis and Pseudoterranova, in marine life. There was a 283-fold increase in the average number of worms from 1962 to 2015 in marine animals commonly used for sushi, which may increase the risk for anisakidosis, a parasitic infection, in humans. Symptoms of anisakidosis include allergic reactions and potential hospitalization, vomiting, diarrhea, and abdominal pain, which could affect those who consume sushi and those who work with fish.
Fiorenza EA, Wendt CA, Dobkowski KA, et al. It’s a wormy world: Meta-analysis reveals several decades of change in the global abundance of the parasitic nematodes Anisakis spp. and Pseudoterranova spp. in marine fishes and invertebrates. Glob Change Biol. Published online March 19, 2020.