Kansas is investigating 20 reported cases of salmonella to determine whether they are linked to an outbreak that has sickened more than 1,000 people nationwide and resulted in the recall of a half-billion eggs.
The state has not yet determined whether any of the cases are tied to the tainted eggs, said Kristi Pankratz, spokeswoman for the Kansas Department of Health and Environment.
The type of salmonella linked with the egg recall, salmonella enteritidis, is very common, she said.
Iowa's Hillandale Farms said Friday it was recalling more than 170 million eggs — some sold in Kansas — after laboratory tests confirmed salmonella. Earlier this week, another Iowa farm, Wright County Egg, recalled 380 million eggs.
FDA spokeswoman Pat El-Hinnawy said the two recalls are related. The strain of salmonella bacteria causing the poisoning is the same in both cases, salmonella enteritidis.
Federal officials say it's one of the largest egg recalls in recent history. Americans consume about 220 million eggs a day, based on industry estimates. Iowa is the leading egg-producing state.
The eggs recalled Friday were distributed under the brand names Hillandale Farms, Sunny Farms and Sunny Meadow. The new recall applies to eggs sold between April and August.
Hillandale said the eggs were distributed to grocery distribution centers, retail groceries and food service companies that serve or are located in 14 states: Kansas, Arkansas, California, Iowa, Illinois, Indiana, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, Texas, and Wisconsin.
The eggs were packaged in six-, 12-, 18- and 30-egg cartons, and in cases of five dozen, the company said. Other eggs were packaged under the Wholesome Farms and West Creek brands in 15- and 30-dozen tray packs.
The company said that consumers who bought these brands should check the egg cartons for two key identifying stamps. One is the number of the plant in which the eggs were produced — P1860 or P1663. The second is the so-called Julian or packing date codes — in this case, ranging from 099 to 230 for cartons with a plant number of 1860, and from 137 to 230 for cartons with a plant number of 1663.
Thoroughly cooking eggs can kill the bacteria. But health officials are recommending people throw away or return the recalled eggs.
A food safety expert at Cornell University in Ithaca, N.Y., said the source of the outbreak could be rodents, shipments of contaminated hens, or tainted feed. Microbiology professor Patrick McDonough said the salmonella bacteria is not passed from hen to hen, but usually from rodent droppings to chickens. This strain of bacteria is found inside a chicken's ovaries, and gets inside an egg.
CDC officials said Thursday that the number of illnesses related to the outbreak is expected to grow. That's because illnesses occurring after mid-July may not be reported yet, said epidemiologist Christopher Braden of the federal Centers for Disease Control and Prevention.
Almost 2,000 illnesses from the strain of salmonella linked to both recalls were reported between May and July, almost 1,300 more than usual, Braden said. No deaths have been reported. The CDC is continuing to receive information from state health departments as people report their illnesses.
The most common symptoms of salmonella are diarrhea, abdominal cramps and fever within eight to 72 hours of eating a contaminated product. It can be life-threatening, especially to those with weakened immune systems.
The form of salmonella tied to the outbreak can be passed from chickens that appear healthy. And it grows inside eggs, not just on the shell, Braden noted.