After a Listeria outbreak involving bagged salads produced by Dole, the U.S. Centers for Disease Control and Prevention is now including leafy greens on food history questionnaires that are used to interview foodborne illness patients. Had leafy greens been on the questionnaire already, the outbreak may have been detected much earlier.

The contaminated bagged salads--produced by a Dole plant in Springfield, OH--caused 33 illnesses in the U.S. and Canada. The outbreak was also reportedly linked to one death in the U.S. and three deaths in Canada.

The presence of Listeria in Dole’s Springfield, OH plant dates back to July 2014. Contamination was also discovered at the plant in 2015, suggesting that the plant continued to operate without addressing the food safety violation. The plant was forced to shut down in January after samples collected by the U.S. Food and Drug Administration and the Canadian Food Inspection Agency tested positive for Listeria. The plant reopened in April after updating sanitation methods and procedures.

In May, the U.S. Department of Justice announced that Dole was officially under criminal investigation. At that time, some media reports alluded to Dole’s deliberate masking of the plant’s Listeria presence. According to federal investigators, Dole failed to test surfaces that came into direct contact with food. Also, Dole apparently tested areas of the plant before food production and sanitizing took place, making it more difficult to determine whether or not the required sanitation procedures really worked or not.

According to the CDC, Dole's Listeria outbreak is the first of its kind associated with leafy greens. Since 2008, it is the eigth Listeria outbreak associated with fresh produce.

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