YAKIMA -- The food industry and government regulators have focused for years on finding the most virulent strain of E. coli bacteria, which has killed hundreds of people and sickens thousands every year.
But they don't regularly test for six less common E. coli strains that can cause illnesses equally as serious. Most recently, two dozen illnesses in four states were tied this spring to bagged romaine lettuce contaminated by an uncommon E. coli strain that can be difficult to detect.
Industry officials said tests aren't available to do widespread monitoring of these other strains, but food safety advocates have begun pushing the government to step up surveillance after several outbreaks.
They're motivated by what has happened to people such as Shiloh Johnson, who two years ago picked at a roll, fried chicken, sunflower seeds and olives from a restaurant buffet. Within days, the 10-year-old was hooked to a ventilator in an Oklahoma hospital, one of 341 victims of an E. coli outbreak. She remained hospitalized for six weeks.
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Investigators tied the outbreak to one of the six less common E. coli strains, and her mother, Belinda Johnson, has endorsed a petition that includes their story in urging the U.S. Department of Agriculture to test for additional E. coli strains.
Many food producers have balked at such a move, questioning the feasibility of eliminating all toxin-producing strains from products.
Dr. Patricia Griffin, head of the CDC's food-borne illness epidemiology section, said she is sympathetic to their argument because not all strains of E. coli appear dangerous.
"The problem is it's a little slippery to say which ones cause human illness. We don't have it defined yet," she said. "We know those six, and we know a few others, but the others are still in a gray zone."
Illness from eating tainted meat can be avoided by cooking it thoroughly and using a meat thermometer to confirm it has reached a temperature of at least 160 degrees.
Marler hired a private Seattle area lab, IEH Laboratories, to sample ground beef nationally for these strains to determine their prevalence. So far, about 1 percent of samples have been tainted and could have potentially caused illness.
IEH Laboratories President Mansour Samadpour said his lab has worked with some in the produce industry to monitor for these strains in the past three years, though there is no required testing. As for meat, Samadpour argued the USDA needs to set standards for testing.