In the latest analysis of packaged leafy greens, Consumer Reports found that nearly 40 percent of samples tested contained bacteria consistent with poor sanitation and fecal contamination.
Leafy greens have been under particular scrutiny since late 2009, when the Center for Science in the Public interest put them atop the 10 most dangerous foods regulated by the FDA list. According to the Center for Disease Control and Prevention (CDC), leafy greens have caused 363 food-borne illness outbreaks in more than 13,500 reported cases since 1990.
"You might think that 'prewashed' and 'triple-washed' salad greens sold in clamshells or bags are squeaky clean," Consumer Reports said, "but our recent tests found much room for improvement."
In a sample of 208 containers representing 16 brands, all well within their use-by dates, Consumer Reports found a common presence of bacteria used to gauge pathogen contamination--in some cases at very high levels. The tests were conducted at an outside lab with financial support from the Pew Health Group.
Consumer Reports tested for total coliforms and other bacteria, including enterococcus, that are reliable indicators of fecal contamination and poor sanitation. While there are no existing federal standards for indicator bacteria in leafy greens, there are standards for these bacteria in milk, beef, and drinking water.