By Sharon Omahen
University of Georgia
In the wake of one death and many cases of foodborne illness related to contaminated spinach, University of Georgia microbiologist Michael Doyle recommends avoiding commercially bagged greens and vegetables.
An internationally known expert on foodborne pathogens like E. coli 0157:H7, Doyle spent most of the week following the outbreak, fielding reporter calls from across the nation.
E. coli O157:H7 causes diarrhea, often with bloody stools. Most healthy adults can recover completely within a week, but some people develop a form of kidney failure called Hemolytic Uremic Syndrome. This condition usually occurs in young children, elderly people and others with low immune systems.
Past cases linked to other vegetables, fruit
"Although this outbreak involves bagged spinach, previous E. coli and salmonella outbreaks have been traced to bagged lettuce, melons and tomatoes," said Doyle, director of the UGA Center for Food Safety in Griffin, Ga.
Doyle says the number of outbreaks may be increasing in part because of the way processors handle produce.
"Some processors have cut and bagged vegetable crops in the field," he said. "This increases the chance for contamination, especially in leafy crops like spinach, lettuce and other greens."
E. coli can be transmitted to crops by manure used as fertilizer or by contaminated irrigation water.
To reduce the number of future outbreaks, the produce industry needs to develop critical control points or treatments throughout the harvesting and packing process to kill harmful bacteria, Doyle said. But he adds that this would require a mandate by the federal government.
Avoid raw spinach for now
While the current outbreak is under investigation, the U.S. Food and Drug Administration recommends that consumers avoid eating raw, bagged spinach and fresh spinach.
Cooking spinach to 160 degrees Fahrenheit will kill any harmful organisms. Washing, even in warm water, may not be enough to eliminate all of the bacteria that may have become embedded in the plant tissues when stalks or leaves are broken.
Doyle doesn't recommend microwaving spinach, as microwave cooking can result in hot and cold spots. "The cold spots can still contain live E. coli," he said.
Georgia farmers not affected
While California farmers suffer the effects of the recent E. coli outbreak linked to bagged spinach, farmers here in Georgia are unaffected, said Kevin Hendrix, president of the Georgia Fruit and Vegetable Growers Association.
"I don't know of anyone in Georgia who grows spinach or lettuce commercially," said Hendrix, a Vidalia onion farmer and owner of Hendrix Produce in Metter, Ga.
UGA Extension vegetable horticulturist Terry Kelley agrees.
“We may have a dab of spinach in a few fields around the state,” Kelley said. “And we also probably have a handful of other leafy vegetables such as romaine lettuce, arugula, endive, escarole, etc. in very small quantities.”
According to the UGA 2005 Farm Gate Value Report, Georgia farmers devoted 20,378 acres to greens, which are defined as collards, kale, lettuce, mustard, spinach and turnip greens. This section of the state's overall vegetable crop contributed more than $52 million to the state's economy.
“Most of the greens grown in Georgia are collards, turnips, mustard and kale,” Kelley said. “They are generally eaten cooked, but not always.”
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)