July 29, 2015 — There’s something about the clean taste and supple, sensuous texture of raw fish that is greatly appealing, but there are some risks you should be aware of, especially if you or anyone you wish to feed is pregnant, elderly, very young, or has a compromised immune system. That holds true for ceviche—which starts out with fresh seafood marinated in lemon or lime juice and then gets tricked out with whatever takes a chef’s fancy—as well as more obvious raw-fish dishes. The acid in the juice turns translucent seafood white and almost opaque, but even though ceviche may look cooked, it’s not. (Far less fraught for the home cook is a ceviche composed of lightly cooked seafood.)
There is, of course, the ever-present risk of harmful bacteria, so easily transferred to food through unhygienic handling or kitchen practices. “Most recently, sushi was believed to have caused at least 50 illnesses in a nine-state Salmonella outbreak,” reported Food Safety News on July 14, 2015. “In 2012, raw tuna contaminated with Salmonellacaused an outbreak that sickened more than 300 people in 26 states.”
And then there are the parasites that are present in certain kinds of fish. They’re a natural occurrence, not caused by contamination, and according to Seafood Health Facts—a joint project of Oregon State University, Cornell University, the universities of Delaware, Rhode Island, Florida, and California and the Community Seafood Initiative—two types of parasitic worms can infect humans: “Anisakiasis is caused by ingesting the larvae of several types of roundworm [aka nematodes] which are found in saltwater fish such as cod, plaice, halibut, rockfish, herring, pollock, sea bass and flounder. Tapeworm infections occur after ingesting the larvae of diphyllobothrium, which is found in freshwater fish such as pike, perch and anadromous (fresh-saltwater) fish such as salmon.”