A pig, a bug, a bag of spinach: It sounds like the answer to a riddle, and in a way, it is. Sometime late last summer, a wandering band of wild pigs trampled a fence and trotted into a spinach field in California’s Salinas Valley. As they rooted around in the leafy greens, they most likely left behind feces infested with a virulent strain of the intestinal bacterium Escherichia coli—picked up, it appears, from a nearby cattle pasture. The hardy breed of E. coli, dubbed O157:H7, normally lives harmlessly by the billions at the rear end of a cow’s gut. But in this case, the bacteria nestled craftily in the crevices of the spinach leaves, sticking to the vegetables as they were harvested, chopped, washed, bagged, and then transported across the country to states from Oregon to Maine. In September and October, nearly 200 people who dined on the infested spinach became ill with bloody diarrhea. Thirty-one developed severe kidney disease, and three people died.
Scientists at the Food and Drug Administration traced the toxic strain of E. coli to the California ranch after testing bacteria-tainted spinach leaves and matching them to fecal samples from a wild boar that had been killed on the farm—the first time an outbreak of E. coli poisoning from produce had been tracked directly to its source. This spate of illness was just one of at least three major produce-linked outbreaks of E. coli O157 that occurred in 2006, triggering a nationwide fear of fresh vegetables. In November and December, 71 people in five states became sick after eating at Taco Bell outlets, an epidemic that was later traced to contaminated iceberg lettuce, and another 81 in three states became sick after eating tainted lettuce at a fast-food chain called Taco John’s.
