A Novel Cause of Food Poisoning — Something's Fishy

Outbreaks of an unidentified foodborne illness associated with the consumption of raw fish, but of unknown etiology, have increased in Japan during the past decade. Symptoms — vomiting and diarrhea — typically begin 2 to 20 hours after ingestion of the fish and last about 24 hours. Researchers in Japan recently conducted an investigation of cases reported in that country from 2008 to 2010.

Epidemiologic analysis involving >1300 affected individuals from 24 municipalities implicated a single fish species — Paralichthys olivaceus, the olive flounder — as the food vector. Microscopic examination of P. olivaceus muscle from farm-cultured fish and from remnants of meals ingested by patients revealed six-valved spores consistent with a myxosporan …