Romaine Lettuce E. Coli Outbreak Source Identified As California

Nearly a week after advising the public about another E. coli outbreak, US officials are back with an update: the source of the contaminated products. According to the Food and Drug Administration, the new E. coli O157:H7 strain that has impacted consumers in both the United States and Canada originated from various romaine lettuce farms in California.

Officials with the CDC and FDA made the discovery during its investigation over the Thanksgiving holiday, according to the Administration. The probe is still underway, but has been narrowed down to some areas in California that grew romaine lettuce over the summer.

Officials believe the contamination specifically affects the "end of season" lettuce harvested from these farms, which span from central to northern California. Lettuce harvesting in California's Central Coast — which is believed to be the primary source — has come to an end for the year.

Now that winter has settled into applicable parts of the US, romaine lettuce crops have transitioned to desert regions in California and Arizona, as well as Florida. The contamination happened "well before" the winter romaine lettuce farming started, according to the FDA, which says it is unaware of any contamination that may be present at the new growing locations.

Though there is likely romaine lettuce coming from non-contaminated regions in the US, the FDA says the US market should have a "clean break" in the romaine lettuce supply chain in order to ensure that all possibly contaminated lettuce is purged from the market.

The CDC announced on November 20 that any and all romaine lettuce products in the US should be thrown away due to the risk. Grocery stores and restaurants across the nation promptly threw away their inventories and the FDA believes the "clean break" was achieved during that process. The FDA says it has been talking with industry officials on product labeling that will include source of origin and date to help deal with any potential future recalls.