Pistachios had tested positive for salmonella for months

TERRA BELLA, Calif. -- The company that recalled 2 million pounds of pistachios on Monday had been receiving positive salmonella tests for as long as five months, federal officials say.

Salmonella in nuts from Setton Pistachio was detected by one of the company's food-manufacturing customers. When the Food and Drug Administration asked Setton officials if any of their own tests had come back positive for salmonella, the answer was yes, says David Acheson, FDA associate commissioner.

"They told us, 'We've had montevideo, newport, senftenberg and larochelle,'" Acheson says, meaning the earlier discovery of four strains of salmonella.

"The question is, 'Did Setton Farms have an ongoing problem, and what did they do about it?' " Acheson says.

The FDA believes batches of pistachios that tested positive for salmonella were destroyed, not distributed. Setton Pistachio spokeswoman Fabia D'Arienzo could not confirm that.

No illnesses tied to the contamination have been confirmed, the FDA says. The agency is currently checking four salmonella cultures provided by Setton to see if they match bacteria in people who have become ill.

"If I'm getting a positive (result) and a couple of months later another positive, and then another, I would think the appropriate response would be to say, 'This is not right. I've got to figure this out,' " says Linda Harris, an expert on salmonella in nuts at the University of California-Davis.

That doesn't necessarily mean the plant has to be shut down and all the workers put out of work, she says. But, "You certainly want to stop and do a complete clean and sanitize."

Perhaps because pistachios have always been considered at low risk for bacterial contamination, Setton officials "were not paying close attention," says Michael Hansen of the advocacy group Consumers Union. And without stronger federal regulations on food safety, there was no reason for them to, he says.

The salmonella problem came to light when Georgia Nut of Skokie, Ill., did its own routine testing and found salmonella in Setton pistachios it had purchased, Kraft spokeswoman Susan Davison says.