The FDA, the Centers for Disease Control and Prevention, and state partners continue investigating a multistate outbreak of E. coli O157:H7 linked to slivered onions, according to an FDA update issued Nov. 13.
The slivered onions were served on Quarter Pounder burgers at McDonald’s restaurants in certain states. As of Nov. 13, 104 people infected with the outbreak strain of E. coli O157:H7 have been reported from 14 states, the update said.
Of 98 people with information available, 34 have been hospitalized, and 4 people developed HUS, a serious condition that can cause kidney failure. One death has been reported from an older adult in Colorado, the FDA said. This person is not one of those who developed HUS.
Of the 81 people interviewed, 80 (99%) reported eating at McDonald’s. Seventy-five people were able to remember specific menu items they ate at McDonald’s. 63 of 75 people (84%) reported a menu item containing fresh slivered onions, the FDA said.
FDA, Colorado Department of Agriculture (CDA), and Colorado Department of Public Health and Environment (CDPHE) have collected onion and environmental samples from McDonald’s stores, distribution centers, and firms of interest for laboratory analysis. At this time, one FDA sample of recalled onions has tested positive for E. coli, but it is a non-O157:H7 Shiga toxin-producing E. coli (STEC) and does not match the outbreak strain or any other clinical illnesses.
Whole genome sequencing (WGS) analysis determined that the sample is positive for E. coli O168:H8 and contains the Shiga toxin gene stx2a. Additional sample results are pending.
FDA has completed onsite inspections at a Taylor Farms processing center in Colorado and an onion grower of interest in Washington state, the agency said.
McDonald’s stopped using slivered onions on Quarter Pounder burgers in affected states, and Taylor Farms recalled yellow onions on Oct. 22.
Foodservice customers were notified by Taylor Farms that they should not sell or serve recalled yellow onions. FDA continues working with Taylor Farms and their direct customers to determine if additional downstream customer recalls are necessary. Foodservice customers should not be further distributing recalled onions. According to available information, recalled onions should not be available for purchase in grocery stores. McDonald’s has reintroduced slivered onions from a different onion supplier into their full menu. At this time, there does not appear to be a continued food safety concern related to this outbreak at McDonald’s restaurants, the FDA said.
