The CDC and FDA announced today that a positive sample of the romaine lettuce outbreak strain was found in the sediment of an irrigation system at Adam Bros. Farms in Santa Barbara, California.
The US Centers for Disease Control and Prevention (CDC) and US Food and Drug Administration (FDA) announced today that traceback evidence conducted as part of the multistate E coli outbreak linked with romaine lettuce points to a possible source.
Whole genome sequencing revealed the presence of E coli O157:H7 in the agricultural water reservoir of Adam Bros, Inc. farm in Santa Barbara County, California. The strain of E coli detected in the reservoir on the farm is genetically related to the strains of E coli isolated from individuals infected in the outbreak.
“The FDA will be sending investigators back to this farm for further sampling,” FDA Commissioner Scott Gottlieb, MD, said in a statement, “It’s important to note that although this is an important piece of information, the finding on this farm doesn’t explain all illnesses and our traceback investigation will continue as we narrow down what commonalities this farm may have with other farms that are part of our investigation.”
As a result of this new information, the FDA is updating guidance about consumption of romaine lettuce. Previous guidance, issued on November 28, 2018, called for avoidance of all romaine lettuce harvested in the costal growing regions of northern and central California. The specific counties identified included Monterey, San Benito, San Luis Obispo, Santa Barbara, Santa Cruz, and Ventura.
In its update today, the FDA reported that it is now safe to sell romaine lettuce from Santa Cruz, Ventura, and San Luis Obispo that was harvested after November 23, 2018, as long as the products are properly labeled with the location and date of harvest.
As of December 12, 2018, 59 individuals in 15 states and the District of Columbia, have been sickened in the outbreak. Those who were infected range in age from 1 to 84 years with a median age of 26. Sixty-five percent of the outbreak cases comprise women. Information is available for 50 of the 59 individuals and the data indicate that 23 of the 50 individuals (46%) have been hospitalized, including 2 individuals who developed hemolytic uremic syndrome. No deaths have been reported at this time.
The onset of illnesses ranges from October 5, 2018, to November 16, 2018. Illnesses that occurred after November 21, 2018, may not be reported yet because of the time it takes to report an illness associated with E coli, which can take 2 to 3 weeks.
As part of the investigation, infected individuals were interviewed about consumption and exposures in the week prior to becoming sick. A total of 27 of the 32 people (84%) who were interviewed reported eating different types of romaine lettuce both at home and from restaurants.
The traceback information led the FDA to believe that the outbreak was caused by romaine lettuce harvested from the coastal growing regions of northern and central California. Adam Bros, Inc. is one of the 8 farms that was indicated in the preliminary traceback. The FDA will continue to investigate the other farms identified in the traceback.
Romaine lettuce from Adams Bros. is no longer on the market.
This is an ongoing investigation and the CDC will continue to provide information as it becomes available.
For the most recent case counts associated with the Shiga Toxin Producing E coli O157:H7 Outbreak linked with romaine lettuce, check out the Contagion® Outbreak Monitor.