Costco E. coli outbreak related to vegetables in chicken salad

The E. coli outbreak traced to Costco chicken salads appears to have been caused by vegetables in the salad, rather than the chicken itself, according to company officials.

Tests performed by the Food and Drug Administration and Montana health officials traced the E. coli to an onion and celery mix, rather than the rotisserie chicken itself, Craig Wilson, Costco's vice president of food safety and quality assurance, told USA TODAY. Health officials are performing additional tests to confirm this link.

The vegetables came from Taylor Farms in Salinas, Calif. USA TODAY was not able to reach Taylor Farms for comment on Thanksgiving.

Nineteen people in seven states have been sickened in the outbreak of E. coli 0157, according to the Centers for Disease Control and Prevention. Five victims were hospitalized and two developed hemolytic uremic syndrome, a type of kidney failure. Victims are from Montana, Washington, California, Colorado, Utah, Missouri and Virginia.

The specific type of bacteria in this outbreak, E coli O157, is particularly dangerous, especially for children, said Ben Chapman, an associate professor and food safety specialist at North Carolina State University. E. coli 0157 is more likely than other varieties of the bacteria to cause hemolytic uremic syndrome, which can leave survivors on dialysis, he said.

One in 6 Americans — more than 48 million people — are sickened by the food they eat each year in the country, causing about 3,000 deaths and 125,000 hospitalizations, costing the economy $14.1 billion, according to the CDC.

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More than half of food poisoning outbreaks are related to fruits and vegetables, Chapman said. Fresh produce is particularly vulnerable to contaminants, simply because it's not cooked.

"When it comes to produce, there is no zero risk," Chapman said. "There are just so many points where it can be contaminated, between the field and someone's plate."

E. coli can get into the food chain in a variety of ways. Outbreaks have been linked to animal manure left behind by deer and even wild pigs, Chapman said.

Both Costco and Taylor Farms have good reputations for food safety, said William Marler, a Seattle attorney who has represented victims of food-borne illness and whose law firm operates a data base of food poisoning outbreaks.

"Costco has always done a good job with food safety," Marler said. "They are probably one of the better stores out there, which shows just how vulnerable a supply chain is to E. coli or salmonella. Even if you have the best food safety systems in place, it always requires constant monitoring and oversight."

Likewise, Marler said, "Taylor Farms is a big player in the fresh vegetable industry. They have been around a long time and they have sophisticated systems in place."

But outbreaks can happen even at careful companies. "With mass-produced food, the oportunity for problems is really high," Marler said.

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In 2013, a California Costco store recalled nearly 40,000 pounds of cooked rotisserie chicken because of concerns that it was contaminated with salmonella. That recall shows that even fully cooked chicken is vulnerable to bacteria, if workers inadvertently contaminate the cooked birds with juice from raw chickens, Marler said.

Most recently, an E. coli outbreak linked to the Chipotle restaurant chain has sickened 45 people in six states. That outbreak is caused by a different strain of E. coli and is not related to the Costco outbreak. Health officials have not yet figured out the source of the Chipotle outbreak.

In September, the Food and Drug Administration issued sweeping new rules that will require USA food manufacturers to implement more stringent food-safety operations and preventive measures to avert deadly outbreaks of food-borne illnesses like listeria and salmonella.

The rules follow years of work by regulators amid a rash of food-borne illnesses linked to dirty food processing equipment and poorly designed facilities.

Those incidents include a listeria outbreak last April that killed three at a Kansas hospital where Blue Bell ice cream was served, and another outbreak in 2011 linked to Colorado cantaloupe, which killed 30 people.

In 2009, a salmonella outbreak linked to a Georgia peanut company killed nine and sickened more than 700 people in 43 states. It was that outbreak that prompted the government to move forward on strengthening the food safety system, as well as making it more proactive. Congress actually passed the rules in 2010, but it took the FDA two years to write the specific requirements.