You might want to check the lid on your peanut butter jar before making that next PB&J sandwich.

On Thursday, the Centers for Disease Control and Prevention (CDC) announced it believes a recent U.S. salmonella outbreak is linked to peanut butter.

Consumers are encouraged to throw out jars with a product code on the lid beginning with &#82202111” which shows where the peanut butter was made.

Some 300 people in 39 states, including Alabama, have become ill since August 2006.  Suspected in the outbreak are certain batches of Peter Pan and Wal-Mart's Great Value house brand, both manufactured by ConAgra, Inc.

The contaminated peanut butter was manufactured at ConAgra's only peanut butter plant, located in Sylvester,

Ga. The plant has been shut down pending further investigation.

At the Greenville

Wal-Mart Super

Center Friday, Store Manager Bill McCrary said the shelves had already been stripped of the two brands being recalled.

&#8220We are not taking any chances. We also pulled some jars that didn't have that code on the lid. That has all been taken care of.”

McCrary also said a few customers had come in to Wal-Mart for refunds on their peanut butter.

At Greenville Super Foods, Store Manager Philip Graham has cleared the shelves of any potentially contaminated Peter Pan products.

&#8220We are telling our customers if they have a jar or a lid with the &#82202111” number on it, to bring it to us for an exchange or a refund. My understanding is most grocers in the area are doing this for the convenience of their customers.”

ConAgra said the company is not sure how many jars are affected by the recall. The plant is the sole producer of the nationally distributed Peter Pan brand, and the recall covers all types, smooth and chunky, produced by the plant from May 2006 until now. Great Value peanut butter is also produced by other manufacturers for Wal-Mart.

FDA inspectors visited the shut-down plant on Wednesday and Thursday to try and pinpoint where the contamination occurred. Testing is also being done on some of the salmonella victims' peanut butter jars. According to the CDC, 85 percent of the infected people said they ate peanut butter, and about a quarter of them ate it at least once a day. It was the only food that most of the patients had all recently eaten.

The highest number of cases have been reported in New York, Pennsylvania, Virginia, Tennessee and Missouri. Approximately 60 of the patients were hospitalized, and the CDC reports no deaths from the outbreak.

Salmonella sickens about 40,000 per year in the U.S., killing about 600. Common symptoms include diarrhea, fever, dehydration, vomiting and abdominal pain. In most cases, salmonella is caused by undercooked eggs and chicken. There has been only one known outbreak linked to peanut butter, one that occurred in Australia in the mid-1990s.

Peanut butter is not a food typically associated with the illness, which commonly originates in the feces of birds and animals.

The heating process used in making peanut butter &#8220is sufficient to kill salmonella, should it be present,” said Mike Doyle, director of The University of Georgia's Center for Food Safety.

However, the point in the manufacturing process that occurs after the heating step and prior to placement in jars, could allow an opportunity for contamination, says the FDA.

&#8220I'm sure the manufacturers have a lot of safeguards in place to prevent things like this happening. But unfortunately, every so often, something does slip by which affects the consumer,” McCrary said.

To get a refund, consumers can also send their lids along with their names and addresses to: ConAgra Foods, P.O. Box 57078, Irvine, CA 92619-7078.

For more information, call 866-344-6970.