Tainted tuna appears to be the source of a 20-state salmonella outbreak, according to the CDC and FDA.

Nearly 30 tons of tuna have been recalled by Moon Marine USA Corp., also known as MMI, of Cupertino, Calif. The frozen product is made up of raw tuna "backmeat" scraped from the bones." It's called Nakaochi Scrape and is made at a processing facility in India.

The product looks like raw ground tuna. It's not sold directly to consumers, but is widely used in sushi, sashimi, ceviche, and similar dishes. "Spicy tuna" dishes often contain the product.

Since Jan. 28, 116 people have fallen ill with the same unusual salmonella strain, called Bareilly. Twelve people have been hospitalized. There have been no deaths.

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