One of the nation's largest egg producers is recalling millions of eggs because of a salmonella outbreak.
The Wright County Egg Farm in Galt, Iowa, announced a voluntary recall of 228 million eggs after they were linked to hundreds of cases of salmonella poisoning in California, Colorado and Minnesota.
The U.S. Food and Drug Administration is investigating the farm to try to find the source of contamination.
"Wright County Egg is fully cooperating with FDA's investigation by undertaking this voluntary recall," the company said in a statement. "Our primary concern is keeping salmonella out of the food supply and away from consumers."
The eggs that are believed to be tainted were sold across the country with 13 brand names: Lucerne, Albertson, Mountain Dairy, Ralph's, Boomsma's, Sunshine, Hillandale, Trafficanda, Farm Fresh, Shoreland, Lund, Dutch Farms and Kemp.
The egg cartons were packaged between May 16 and August 13 and stamped with one of three codes: P-1026, P-1413 or P-1946.
Consumers who believe they may have tainted shell eggs should return them to the store for a full refund, according to the company.
The Centers for Disease Control and Prevention has estimated that the number of people sickened as a result of the salmonella outbreak could be in the thousands.
Symptoms of salmonella-related illness could begin as many as three days after eating the eggs, and include fever, cramps and diarrhea, according to ABC News senior health and medical editor Dr. Richard Besser, and cooking eggs greatly reduces the risk of salmonella poisoning.
Salmonella outbreaks accounted for 142 of the bacterial outbreaks in 2007, including two of the three largest, according to a report from CDC researchers in the Aug. 13 issue of Morbidity and Mortality Weekly Report. The outbreaks included 802 illnesses traced to tainted hummus and 401 illnesses from frozen pot pies.
Rodents in food packaging and distribution facilities are the most common source of salmonella contamination.
For more information on the egg recall, visit the Egg Safety Center: http://www.eggsafety.org.
The Associated Press contributed to this report.