FDA has completed its investigation of the multistate outbreak of E. coli 0151:H7 that occurred last fall and was linked to leafy greens. The FDA and CDC found the outbreak was caused by an E. coli strain that was genetically related to the strain found in the fall 2019 outbreak involving romaine lettuce (Salinas, California). Despite conducting environmental sampling at dozens of ranches in the area, the FDA was unable to identify a single site as the source of the outbreak. However, the analysis did confirm “a positive match to the outbreak strain in a sample of cattle feces,” which was located uphill from where the leafy greens identified in the agency’s traceback investigation were grown, according to an FDA release.

Although the FDA’s investigation has ended, the agency will be reviewing the findings and release a report in the “near future” with recommendations. “In the meantime, as recommended in our Leafy Greens Action Plan, the FDA continues to recommend growers assess and mitigate risk associated with adjacent and nearby land use practices, particularly as it relates to the presence of livestock, which are a persistent reservoir of E. coli O157:H7 and other STEC,” FDA stated in the update.