Questions linger about the contamination source and farming and irrigation practices. But in the current spinach-related E. coli O157:H7 outbreak, at least word got out quickly, says Susan Brink for the Los Angeles Times.

Less than a week elapsed between Sept. 8, when Wisconsin notified the Centers for Disease Control and Prevention of an uptick in E. coli cases, and Sept. 14, when the Food and Drug Administration told stores, restaurants and consumers to chuck their spinach. "This is an example of how fast it can work," says Dr. Patricia Griffin, acting chief of enteric diseases at the CDC.

Meat, poultry and produce that grows close to the ground (such as spinach, lettuce and cilantro) have all been implicated in E. coli outbreaks. It was even found inside watermelons, says Dr. Jeffrey Griffiths, professor of public health and family medicine at Tufts University School of Medicine, after sellers started injecting the fruit with water to make it heavier and increase its price.