Back in January, the state of Ohio and federal Centers for Disease Control and Prevention discovered and investigated Listeria contamination in salad greens that came from a Dole processing plant in Springfield, OH. The plant has been closed since January, and Dole started limited production this week, but the company announced exactly what the source of contamination was or how they were able to eradicate it.

The CDC was able to identify the bacteria in patients beginning in July 2015, and the last documented case was in January of 2016. There were a total of 33 people in the United States and Canada who were confirmed ill with the pathogen from the Springfield plant, with 19 patients in the United States and 14 in Canada.

“Confirmed” cases, in food poisoning, are people who were ill enough to visit a doctor or who were hospitalized and had samples of their blood or feces taken to be matched to the CDC database. Of the known patients who died, one was in the U.S. and three were in Canada.

“After fully coordinating with these regulators, limited production has restarted and will expand in the coming weeks,” the company said in a statement. The company also expressed gratitude to its employees and local residents in Springfield, OH. When asked by Food Safety News, a spokesperson said that the company had no further statements other than the official release.

Dole restarts salad facility; mum on Listeria cleaning process [Food Safety News]

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