Is Our Food Any Safer Since the Last E. Coli Outbreak?

By Carl Nagin, California Coast and Ocean. Posted October 18, 2007.

Late in August 2006, the federal Centers for Disease Control and Prevention (CDC) in Atlanta began investigating cases of severe food poisoning reported by health officials in 26 states and one Canadian province. Over the next six weeks, a rare and particularly virulent strain of Escherichia coli 0157:H7 sickened more than 200 people, hospitalizing half of them, some with severe kidney damage, and killing two elderly women and a child. For epidemiologists, the outbreak presented a breakthrough because a DNA-fingerprinting system enabled CDC investigators to trace back the source of the infections from clusters of cases nationwide.

Bacteria in stool samples of hospitalized patients were genetically matched to pathogens in pre-packaged, "ready to eat" Dole brand spinach that they had recently purchased and consumed. Further, product codes on the bags indicated that the contaminated greens had been processed during one shift on August 15 at a plant then owned and operated by Natural Selection Foods. The company's records showed that the spinach had been harvested from four fields in Monterey and San Benito counties.

Just how the spinach became contaminated and where in the process from field to package the bacteria originated will probably never be known. An investigative report released last March by the Food and Drug Administration (FDA) could make "no definitive determination" as to "how E. coli 0157:H7 pathogens contaminated spinach in this outbreak."

The consequences of the crisis fell heavily on Central Coast farmers, who are now being pressed by buyers to comply with a conflicting array of new food safety measures, some of which are costly, scientifically unproven, and environmentally harmful. Some violate state regulations, and may even be counterproductive to food safety. But the growers must follow these measures in order to market their crops to the larger contractors or handlers.

The farmers' predicament is jeopardizing the future of sustainable agriculture and of the habitat and clean water it supports, according to the Nature Conservancy's Monterey Project Director Chris Fischer: "Farmers and conservationists in California have been working together for more than 20 years to develop practices that help protect water quality and wildlife habitat, but since last fall, farmers have been under enormous pressure from their buyers to go the other direction," she said. "To stay in business, they are being forced to build miles of fences along streams, cut down trees, and bulldoze ponds. Some actions, like creating bare-earth buffers along waterways, may actually increase the risk of contamination downstream."

Search for the Source

The E. coli outbreak of August 2006 was "one of the worst ever reported in produce," stated a 2006 "Critical Issues" report by the nonprofit Organic Center, which conducts peer-reviewed scientific research on organic food and farming. It prompted investigations by the FBI and FDA and led to one of the largest product recalls in U.S. history: On September 14, 2006, the FDA issued a consumer and retailer advisory not to eat or sell any bagged or fresh spinach. This advisory remained in effect until September 22.

Hank Giclas, vice president for science and technology for Western Growers, a produce industry group, remembered the day the nation's spinach industry was shut down. "I was in my office, and we were frantically summoned to a conference call with FDA officials. Their advisory took everyone by surprise. It was an unprecedented action. They'd never before issued any kind of blanket 'Do not consume spinach' warning. The industry ground to a halt."

Members of Western Growers in California and Arizona grow, pack, and ship nearly half the nation's fresh fruits, vegetables, and nuts. Giclas estimated that the shutdown cost the spinach industry roughly $100 million and affected other bagged salad produce as well.

On September 20, five weeks after the Natural Selection Foods plant had processed the spinach for Dole, FDA investigators began taking soil and water samples from four of the ranches where it had been grown and harvested. Samples from one ranch in San Benito County had E. coli pathogens indistinguishable from the strain identified by the CDC's DNA fingerprinting system, PulseNet. These were found in soil, river water, and cow and feral pig feces at Paicines Ranch, a large grass-fed beef operation that had leased a small amount of its land to a spinach grower. But these E. coli-infested samples were found nearly a mile away from the implicated spinach field. None were found on the plot itself.

Whatever the origin and pathways of the outbreak, the washing procedures at the processing plant failed to eliminate the pathogens, and its quality assurance protections failed to detect it after the processing. The FDA report was heavily redacted for "proprietary reasons," advantageous to Natural Selection Foods' operators, who were quick to divert attention back to the fields and away from the manufacturing end.

In an October 15, 2006 article in the New York Times ("The Vegetable-Industrial Complex"), author Michael Pollan, who has written widely about food and its production, noted that "a great deal of spinach from a great many fields gets mixed together in the water at that plant, giving microbes from a single field an opportunity to contaminate a vast amount of food. The plant in question washes 26 million servings of salad every week. In effect, we're washing the whole nation's salad in one big sink."

See more stories tagged with: greens, e coli, spinach, farming

Carl Nagin is a Berkeley-based reporter whose work has appeared in the New Yorker and on the PBS documentary series Frontline.

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