Dec. 13 (UPI) -- The U.S. Food and Drug Administration said Thursday it was able to trace an E. coli outbreak to a California farm.
The FDA's investigation identified a positive sample result for the outbreak strain in the sediment of a local irrigation reservoir used by Adam Bros. Farms in Santa Barbara County. The agency said the farm has been cooperating with the outbreak investigation and hasn't shipped any romaine lettuce since Nov. 20.
So far 59 people in 15 states have been sickened by the E. coli strand with the last reported illness onset date being Nov. 16.
Despite locating an outbreak of the strain at the Adam Bros. farm, it is too soon to determine whether the outbreak has concluded, officials said.
"As of Dec. 13, our investigation yielded records from five restaurants in four different states that have identified 11 different distributors, nine different growers, and eight different farms as potential sources of contaminated romaine lettuce," the FDA said.
As a result of the finding, the FDA revised its recommendations for consumers, stating there is no longer a reason for consumers to avoid romaine lettuce from San Luis Obispo, Santa Cruz and Ventura counties, in California, provided it was harvested after Nov. 23.
Additionally the agency said romaine harvested outside those areas and greenhouse-grown romaine don't appear to be part related to the current outbreak and there is no reason for consumers to avoid lettuce from those sources.
"If consumers, retailers, and food service facilities are unable to confirm that romaine lettuce products are from unaffected sources, we urge that these products not be purchased, or if the products have already purchased, they should be discarded or returned to the place of purchase," the FDA said.