Feed one likely source of salmonella in eggs, federal officials say

(CNN) -- Feed given to hens at two Iowa farms is a likely source of contamination that led to a nationwide salmonella outbreak, but the disease also turned up in manure samples taken around the farms as well, federal officials said Thursday,
The feed could have become contaminated after it went through heat treatment that was sufficient to kill salmonella, officials from the Food and Drug Administration told reporters.
Produced at a mill at a Wright County Egg facility, the feed was given to pullet chickens at both Wright County Egg and Hillandale Farms, which between them recalled more than a half-billion eggs since the salmonella outbreak.
The outbreak has sickened a reported 2,403 people between May 1 and Aug. 25, the U.S. Centers for Disease Control and Prevention said in a conference call. The Salmonella enteriditis number normally for that period is about 933 illnesses.
Testing at two Wright County Egg farms in Iowa showed the presence of salmonella in the food mill and at least two locations, said Sherri McGarry of the Food and Drug Administration. She said investigators are still drawing samples at Hillandale Farms.
Iowa does not have an egg quality assurance program, McGarry said.
The feed could have been contaminated in a number of ways, including by birds, rodents and people's shoes or boots, officials said.
More people will likely report becoming sick because of the two to three weeks it takes for salmonella to manifest itself, said Dr. Christopher R. Braden, acting director of the Division of Foodborne, Waterborne and Environmental Diseases at the CDC.
No deaths have been linked to the outbreak, regulators said, and they expressed optimism that egg safety rules that took effect after the outbreak began will prevent a similar outbreak in the future.
Braden said elderly people living in nursing homes have not fallen sick, as they might have in past outbreaks.
Increased egg safety procedures in restaurants, along with pasteurization and thorough cooking, have put a dent into the outbreak, Braden added.
Rep. Bart Stupak, D-Michigan, has raised questions about safety at the farms, and a House subcommittee reportedly will hold hearings September 14 to look at the companies and the government response.
Egg consumers had two new brand names to search for in their refrigerators Thursday. Wright County Egg said in a news release Wednesday night that it had confirmed cases of Salmonella enteritidis illnesses related to shell eggs bearing the Cardenas Market brand.
Wright County Egg was responsible for 380 million of the 550 million recalled eggs and said 60-egg cases sold under the Cardenas Market brand in California and Nevada were being recalled. Although the Cardenas Market label wasn't named in Wright County Egg's original August 13 recall announcement, Cardenas was immediately notified at the time of the original recall, and product in distribution or in stores has been quarantined, returned or destroyed, Wright County said.
Eggs included in the recall are labeled with plant number 1026 and date codes ranging from 136 to 228.
Dates and codes can be found printed on the label. The plant number begins with the letter P and then the number. The Julian date follows the plant number, for example: P-1026 228.
In addition, Trafficanda Egg Ranch released a statement saying it had confirmed Salmonella enteritidis illnesses from May 17, 2010, to August 17, 2010, relating to its Wright County-supplied shell eggs.
The Trafficanda Egg Ranch-branded eggs were distributed to grocery stores and food-service companies in California in 12-egg cartons, 20-egg over-wrapped packages, and 60-egg over-wrapped packages with date codes ranging from 136 to 229 and plant numbers 1026, 1413, 1720, 1942 and 1946.
According to a spokeswoman for the Egg Safety Center, the two newest "subrecalls" don't add to the total number of eggs recalled; both the Cardenas Market and Trafficanda Egg Ranch eggs were counted already as part of Wright County Egg's 380 million.
That supports Food and Drug Administration Commissioner Margaret Hamburg's statement on CNN's "American Morning" on Monday that there could be some subrecalls. Food safety officials said earlier this week they didn't expect the total number of recalled eggs to rise.
Both recall notices came through the Egg Safety Center, which is run by United Egg Producers, a trade group that describes itself as a cooperative of egg farmers from all across the United States, representing the ownership of approximately 95 percent of all the nation's egg-laying hens.
As public health officials across the country look into the outbreak, the state of California believes it has identified its earliest cases -- and says its investigation helped tip off the rest of the country to the source of the problem.
On May 28 and 29, several people became sick after attending either a prom or a graduation party in Santa Clara County, according to Joy Alexiou, a spokeswoman for the Santa Clara County Public Health Department. Tests on some of the victims, including a catering worker who nibbled on the food, determined that the culprit was salmonella, she said.
That finding triggered an investigation. By interviewing prom- and party-goers about what they had eaten, the Santa Clara County Health Department found at least one common link -- a delicate custard-filled pastry called profiteroles that was served at both events. According to Michael Sicilia, a spokesman for the California Department of Health, the caterer had run out of pasteurized filler and made the rest of the fillings with shell eggs.
Throughout June and early July, county officials noted more clusters of two or more salmonella cases. In all, 42 people in Santa Clara County tested positive for salmonella, including six who ended up in the hospital, Alexiou said.
Similar clusters were popping up all over California, including four in San Diego County -- one traced to a Korean restaurant -- and another incident involving food served on a movie set in Los Angeles, an incident under investigation by Los Angeles County.
In Santa Clara County, investigators were faced with a dilemma: Because the link to eggs didn't emerge for several weeks after people fell ill, there were no eggs left to test. Local investigators relied on interviews with food preparers and companies to draw a trail back to Wright County Egg in Iowa. In other counties, too, the trail led in the same direction, according to health officials.
On July 29, the California Department of Health sent a notice to the U.S. Centers for Disease Control and Prevention and the U.S. Department of Agriculture, warning of a connection to Wright County Egg. Sicilia said the alert helped confirm the suspicions of officials in other states who were also investigating a surge in salmonella cases.
California is just one of 23 states that received eggs potentially contaminated by salmonella from the two egg producers.
New regulations went into effect July 9 requiring egg producers with more than 3,000 hens to take measures designed to prevent the spread of salmonella.
"We believe that had these rules been in place at an earlier time, it would have very likely enabled us to identify the problems on this farm before this kind of outbreak occurred," the FDA's Hamburg said.
While FDA inspectors typically didn't inspect farms until after an outbreak of illness, Jeff Farrar, the associate commissioner for food safety at the FDA, said that under the new rule, "We will be beginning routine inspections of egg farms throughout the United States."
Farrar would not release details of the inspections, which also involve a third operation that supplied the two egg producers, but the results could be released later this week, he said.
While the recall involves hundreds of millions of eggs, they represent less than 1 percent of the 80 billion eggs produced in the United States each year, said Krista Eberle, director of the food safety program at the Egg Safety Center.
But even that risk level is too high for some restaurant patrons in Michigan, the most recently added state on the list of those receiving tainted eggs.
"It makes you not even want to order or buy the eggs," Audrey Karas, a customer at a Big Boy in Warren, Michigan, told CNN affiliate WDIV. Big Boy uses eggs unaffected by the recall. "It makes you uneasy about buying eggs, even if they are supposed to be safe."

CNN's Phil Gast and Senior Medical Producer Caleb Hellerman contributed to this report.