OMAHA, Neb. -- ConAgra Foods Inc. told consumers to discard certain jars of Peter Pan and Great Value peanut butter after the spread was linked to a salmonella outbreak that has sickened almost 300 people nationwide.

Lids of jars with a product code beginning "2111" can be returned to ConAgra for a refund, the company said.

This jar of Peter Pan Peanut Butter shown Thursday, Feb. 15, 2007, in Tyler Texas, has the product code beginning with the number "2111" imprinted on the lid. ConAgra said in the aftermath of a salmonella outbreak, that consumers should throw away all Peter Pan and Great Value peanut butter jars produced by ConAgra that have that product code. The affected jars are made by ConAgra in a single facility in Sylvester, Ga., according to officials with the Centers for Disease Control and Prevention. (AP Photo/Dr. Scott M. Lieberman) (Dr. Scott M. Lieberman - AP) In Depth Success Stories Gain inspiration from Lean Plate Club readers who have lost weight ... and kept it off. AIDS/HIV Twenty-five years after the first diagnosis of the first case of AIDS, the world is waking up to the epidemic. Focus on Bird Flu Track the latest developments in the spread of the deadly H5N1 influenza virus. » MORE SPECIAL REPORTS Your Co-Workers Like McSteamy? We can help you find the right work environment with competitive benefits. Nursing, Allied Health: Get a New Job Save & Share Article What's This? Digg Google del.icio.us Yahoo! Reddit Facebook

The salmonella outbreak, which federal health officials said Wednesday has sickened 288 people in 39 states since August, was linked to tainted peanut butter produced by ConAgra at a plant in Sylvester, Ga. How salmonella got into peanut butter is still under investigation, said Dr. Mike Lynch, an epidemiologist at the Centers for Disease Control and Prevention.

CDC officials believe the salmonella outbreak to be the nation's first stemming from peanut butter. The most cases were reported in New York, Pennsylvania, Virginia, Tennessee and Missouri.

About 20 percent of all the ill were hospitalized, and there were no deaths, Lynch said. About 85 percent of the infected people said they ate peanut butter, CDC officials said.

ConAgra officials said it was unsure why the CDC identified peanut butter as the source of the problem. Its own tests of its peanut butter and the plant have been negative, but it shut down the plant so it can investigate, spokesman Chris Kircher said.

"We're trying to understand what else we need to do or should be doing," he said.

Kircher called the recall a precaution. "We want to do what's right by the consumer," he said.

ConAgra officials haven't said how much peanut butter is covered in the recall. The Peter Pan brand is sold in 10 varieties, according to ConAgra's Web site. The Great Value brand, which is also made by other companies, is a Wal-Mart brand.

He said the CDC contacted the Food and Drug Administration, which sent investigators to the Georgia plant to review records, collect product samples and conduct tests for salmonella.

Kircher said ConAgra makes peanut butter only at the Sylvester plant, for distribution nationwide.

ConAgra randomly tests 60 to 80 jars of peanut butter that come off the line each day for salmonella and other pathogens, he said.