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Government & Policy

December 11, 2006
Volume 84, Number 50
pp. 28-30

Food Safety System

Contaminated spinach prompts calls for major overhaul

Bette Hileman

The recent contamination of spinach with Escherichia coli, which resulted in three deaths, led the Food & Drug Administration to advise consumers on Sept. 14 not to buy any of the fresh vegetable. It was not until Oct. 2 that Americans were given a green light to eat fresh spinach again. In the process, the bagged fresh greens industry suffered direct losses estimated to be as high as $150 million.

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Sacked Fresh spinach was banned from supermarkets for more than two weeks because of E. coli contamination.

The spinach incident spurred renewed calls for a single, independent food safety agency that would regulate animal and plant production in an integrated way. Currently, the Department of Agriculture regulates meat, poultry, and processed eggs, and FDA is responsible for nearly all other foods, including fresh produce and fish. "For practical purposes, no agency oversees what happens on farms except for those that produce eggs," says Marion Nestle, professor of nutrition at New York University.

The spinach tragedy has also given rise to a number of other suggestions for improving the safety of fresh produce, including irradiating it with electron beams to kill E. coli and labeling cartons or packages with special identifiers that tell where the produce was grown and processed so any bacterial outbreak can be traced immediately to the source.

There is a great disparity between the food safety resources at USDA and FDA. USDA has about 7,000 people inspecting 6,000 processing plants daily, but on average, FDA's 800 inspectors can visit a particular processing plant only once every five years.

Because of the huge difference in resources for inspection and research, some members of Congress, the Government Accountability Office, and various public interest groups have periodically called for the creation of a single, independent food safety agency. Such an entity would combine the food safety functions of FDA and USDA and allocate resources according to risk. However, officials at both agencies have said repeatedly that the current system would not be improved by establishing a single administration.

Now, the severity of the disease outbreak from spinach, along with 35 other recent food contamination incidents, has led to heightened interest among lawmakers to reform the food safety system, says Rep. Rosa L. DeLauro (D-Conn.). "In the past several months, this country has seen a staggering number of recalls involving bagged spinach, lettuce, bottled carrot juice, egg salad, ground beef products, and most recently, turkey," she says. "It is disappointing that Bush Administration officials refuse to acknowledge the problem. The system is broken, and Congress needs to act to protect public health."

In 2005, DeLauro and Sen. Richard J. Durbin (D-Ill.) introduced bills that would create a single food safety administration. The legislation failed to attract much support. Next year, they plan to introduce similar bills.

"Legislation creating a single food safety agency will have a much better chance of passage in the next Congress, in part because the leadership has now shifted to the people who have been working on this issue for many years," says Caroline Smith DeWaal of the Center for Science in the Public Interest.

"The spinach outbreak provided the same kind of wake-up call for the produce industry as the 1993 Jack in the Box outbreak provided the beef industry," DeWaal says. Hundreds of people were sickened and four children died from eating undercooked Jack in the Box hamburgers contaminated with E. coli 0157:H7.

This year, between Aug. 30 and Sept. 9, individuals from 26 states began falling ill from symptoms of poisoning by the same deadly bacteria, E. coli 0157:H7. Eventually, the Centers for Disease Control & Prevention (CDC) determined that 95% of the patients had consumed fresh bagged spinach. Their symptoms generally included nausea, severe abdominal cramps, and bloody diarrhea. In all, 204 people were sickened, including 102 who were hospitalized. Thirty-one of the patients developed kidney failure, and two elderly women and one two-year-old child died.

FDA and CDC analyzed the DNA of the E. coli that had sickened the patients and that of the spinach they had eaten. The agencies concluded that all of the contaminated spinach had been processed by Natural Selection Foods of San Juan Bautista, Calif. They also found that the vector for the contamination was most likely feral pigs that wandered across a free-range cattle ranch, picked up E. coli from excrement, and carried it into neighboring spinach fields.

According to William D. Marler, a lawyer at Marler Clark, in Seattle, the strain of E. coli 0157:H7 that caused the outbreak was extremely virulent, on the basis of the unusually high proportion of those who became seriously ill after developing symptoms. Marler, who represents 97 victims, is suing Natural Selection Foods, the farm where the spinach was grown, and the adjoining ranch that the pigs visited before roaming onto spinach fields.

Before 1995, food-related E. coli infections were mainly associated with meat processing. But in response largely to the Jack in the Box incident, USDA put in place a systematic testing requirement when it set up the Hazard Analysis Critical Control Points (HACCP) system for meat processing plants in 1996. As a consequence, meat-related E. coli infections have declined.

Since 1996, E. coli 0157:H7 infections in humans have been linked mostly to fresh produce, much of it from central California. In all, 20 incidents involving leafy vegetables have occurred in the past decade.

"Industry is developing a plan to minimize outbreaks in the future," says David Acheson, chief medical officer at FDA's Center for Food Safety & Applied Nutrition. "Natural Selection Foods is planning to start testing raw produce."

A new approach is needed, suggests Dennis G. Maki, professor of medicine at the University of Wisconsin School of Medicine. Infection from E. coli 0157:H7 is "what we call a disease of progress," he says. The species was first isolated and characterized in 1982, he explains, and has caused an increasing amount of food- and waterborne disease over the past 15-20 years because of tremendous changes in how we produce food in the developed world.

"For example," Maki says, "if you eat a hamburger anywhere, whether at home or in the richest hotel in New York City, that hamburger was probably commercially produced. The animal from which the hamburger was made may have been on the open range for much of its life, but it probably ended up eating grain on a huge feedlot for its last three or four months," he explains. "Grain feeding greatly increases the capacity of E. coli to survive in the colon in cattle."

In many cases, 50,000 cattle live on one feedlot, producing huge amounts of manure, Maki says. The manure is often stored in pond-size lagoons that can leak during heavy rainstorms, contaminating wells, rivers, and sometimes irrigation water used on spinach and lettuce, he explains.

Eliminating E. coli outbreaks from leafy vegetables "is a formidable challenge," Maki says. In addition to quality control in processing, "I think we ought to be irradiating many of our commercially produced foods," he says. "More than 4 million tons of lettuce, spinach, and sprouts are consumed in North America every year, and it is unclear how much the contamination risk is reduced by rewashing the produce at home."

Alejandro Castillo, associate professor in the department of animal science at Texas A&M University, has been conducting research on spinach irradiation. After inoculating spinach with three strains of E. coli 0157:H7, he irradiated it with electron beams from a linear accelerator. He found that an energy dose of 1.2 kilograys, a medium dose for food, reduces all three strains to below the detection limit, 10 cells per gram. The appearance of the spinach leaves was unchanged by the irradiation, and shelf life may be improved, he says. Irradiation may be a viable alternative for decontamination of spinach leaves, he explains, "but it should not substitute for good agriculture practices and sanitary processing." Castillo believes spinach irradiation would be cheap because ground beef irradiation costs only a few cents per pound.

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Culprit Feral pigs probably caused the spinach contamination.

But NYU's Nestle claims that irradiation is not a solution for pathogens. "If we use late-stage technologies like irradiation, all the efforts to try to prevent pathogens would disappear," she says. "It would instill a false sense of security." Instead, she argues, "there should be a single food agency that can oversee both the animal and plant side of food safety." To prevent something like the spinach incident, "someone needs to be looking at the big picture rather than looking at the situation in the usual fragmented way," she explains.

Tracking capability is another key missing element, says William R. Pape, president of AgInfoLink Global. What is needed on each carton of newly picked produce is a "license plate" with a code that could be used to identify electronically where the produce was grown, he says. That same code, along with processing plant data, could be duplicated on outgoing bags and cartons from the plant, he says. He estimates the labeling system would add only about 0.5% to the cost of produce. With this system, just a day or two would elapse between the time contamination is found on produce and the time the field where it was grown is identified, Pape says, in contrast to the weeks it took to identify the source of the contaminated spinach. "The produce industry is mostly talking about more testing for contamination, but they also need to add a traceability component," he says.

According to Michael R. Taylor, an epidemiologist at the University of Maryland School of Medicine, the primary missing element is resources. FDA does not have the resources to do inspections and set up testing systems, nor does it have a mandate "to drive primary prevention at the point of production," he says. Another problem, he says, is no one—not the head of CDC, FDA, or USDA or California officials—is in charge of preventing the next outbreak of E. coli in spinach or lettuce. When it comes to food, Taylor says, "all play a role, but no one is in charge, and no one fairly can be held accountable."

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