Federal investigators said a number of California farms may have produced romaine lettuce contaminated with E. coli, causing an outbreak in late 2018 that hospitalized dozens of Americans, a report released Wednesday said.
The farms were not identified in the FDA’s report, except for Adam Brothers Farming of Santa Barbara County, the only farm in which investigators found a positive match for E. coli. Adam Brothers issued a recall for cauliflower and red and green leaf lettuce in December.
The investigation continued throughout the government shutdown, during which the outbreak was declared over on Jan. 9.
Of the sick people interviewed, 83 percent reported eating romaine lettuce the week before the illness. Officials announced the outbreak days before Thanksgiving, causing a nationwide purging of romaine lettuce. Overall, the outbreak sickened 62, hospitalizing 25 across 16 states.
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The lone positive E. coli test was found in sediment in a water reservoir on an Adam Brothers farm in Santa Maria. The agency stated it did not know how the reservoir became contaminated but provided possibilities, including that the water was “most likely” not properly treated with sanitizer and extensive wild animal activity nearby, such as animal grazing.
It’s also possible that E. coli was in the reservoir for months or years before the outbreak.
The other farms implicated in the outbreak did not use the reservoir. The FDA stated investigators could not find a potential source of contamination at those farms.
FDA Commissioner Scott Gottlieb and deputy commissioner Frank Yiannis recommended farmers review federal produce safety rules and said the agency will work with the produce industry to create quick and accurate ways to trace outbreaks back to their source.
The investigation was conducted by the FDA, the U.S. Centers for Disease Control and Prevention, individual states and Canadian officials.