You wouldn’t think peanut butter could have such long-lasting, ill effects, but the company whose peanut products caused a nationwide outbreak of salmonella infections is now recalling everything it has manufactured at its contaminated Blakely, Ga., plant since January 1, 2007.

Peanut Corp. of America (PCA) announced the recall yesterday, after the Food and Drug Administration (FDA) released documents showing that PCA in 2007 and 2008 knowingly sold products that it had tested and knew were tainted. The embattled manufacturer earlier this month pulled peanut butter and peanut paste (used in baked goods and candies) made at its Blakely plant after July 1 of last year, but has now expanded the recall to dry and oil roasted peanuts, granulated peanuts and peanut meal made there after January 1, 2007. The lots begin with number 7, 8 or 9 and were distributed to institutions, food service industries, and food companies around the country and in Canada, Haiti, Korea and Trinidad.

The peanut butter, as well as the goodies made from them, are being recalled because they could potentially be tainted with salmonella, including both the salmonella typhimurium strain responsible for the outbreak as well as other types of the bacteria, FDA Director of Food Safety Stephen Sundlof said yesterday on a press telephone briefing. (Click on the January 28 media briefing hyperlink for a PDF of the transcript.)

Sundlof stressed that the agency was expanding the list of salmonella suspects as a precautionary measure, noting that it had no evidence of illnesses linked to strains other than typhimurium. PCA said in a statement that it hasn’t received any complaints or reports of illnesses about the newly recalled products. The outbreak has sickened 51 people — half of whom are under 16 years old — in 43 states and may be linked to eight deaths; all of the dead were age 59 or older, according to the Centers for Disease Control and Prevention (CDC).

“We have been devastated by this, and we have been working around the clock with the FDA to ensure any potentially unsafe products are removed from the market immediately,” PCA President Stewart Parnell said in the statement released yesterday to reporters and on the company's Web site. “We want our customers and consumers to know that PCA is taking extraordinary measures, out of an abundance of caution, to identify and recall all products that have been identified as potential risks.”

But can salmonella really survive in peanut butter for two years? According to Michael Doyle, director of the Center for Food Safety at the University of Georgia, it can, because peanut butter lacks acidity that would help kill the bacteria. In fact, peanut butter's high fat content protects salmonella, Doyle says. "Salmonella is very stable in peanut butter — for many months to a year it survives," he says. "It won't grow, but it survives."

For that same reason, even small doses of salmonella-tainted peanut butter can cause infection. Stomach acid, a first line of defense against germs, doesn't break down the fats in peanut butter, which would potentially reduce the amount of salmonella a person would be exposed to, Doyle says. Salmonella causes symptoms including diarrhea, high fever and abdominal cramps, and may be deadly in young children, the elderly and people with compromised immune systems.

But should you really be eating two-year-old peanut butter anyway? "From a quality standpoint, peanut butter has a best-use-by date of about a year," Doyle says. "But the reality of it is, if it still tastes good to the person, they'll keep it."

Peanut butter by PiccoloNamek via Wikimedia Commons