Although authorities declined to identify the specific brand of mixed salad responsible for the outbreak, they explained that it consisted of romaine lettuce, red cabbage, and carrots. The tainted product has sickened 145 people in Iowa and another 78 in Nebraska — well over half of the total number of people affected by the outbreak.
Still, federal officials cannot pinpoint the salads as the definitive — or the only — origin for all of the cases. Foods like mixed salad are prepackaged by mammoth corporate distributors and disbursed throughout the country, making it difficult to know at what stage of the process the contamination occurred and often necessitating nationwide recalls of an unsafe product.
Vegetables and leafy greens are actually among the most common sources of food-borne pathogens. The CDC released a comprehensive study in January in which it found that one in five food-related illnesses were linked to leafy greens, and almost half of all food poisonings were caused by produce in general. Between 1998 and 2008, there were 236 vegetable-related deaths — a number that is second only to the 277 poultry-related deaths over the same time period.
Those findings led the CDC to implicitly call for greater inspection of fruits and vegetables. The Food and Drug Administration (FDA) proposed stricter sanitary guidelines for farm workers handling produce to keep it from being tainted by animal waste or dirty water at the beginning of 2013. Food safety officials emphasize that it is important for consumers to thoroughly wash both fresh and prepackaged produce to reduce the possibility of an outbreak.