A recent report from the U.S. Food and Drug Administration (FDA) has linked the source of three E. coli outbreaks in the fall of 2019 back to leafy greens operations in the Salinas Valley that were in the proximity of grazing livestock. The report indicates that after whole genome sequencing tests the outbreaks were caused by three distinctly different strains of E. coli.
According to the FDA, “these key findings reinforce our concern about the possible impacts of nearby and adjacent land use on the safety of leafy green crops and further underscore the importance of implementing appropriate risk-based preventive measures to reduce the potential for contamination of leafy greens.”
The FDA’s investigation found that the outbreaks could be traced back to a common grower with multiple ranches and fields that supplied romaine lettuce to a variety of businesses that were associated with the outbreaks. The same strain of E. coli was discovered in two brands of fresh-cut salads and was also detected in a fecal-soil sample obtained from a cattle grate upslope from a farm with multiple fields related to the outbreaks. The report emphasized that cattle are a persistent source of E. coli outbreaks in leafy greens, which is “especially true when cattle are adjacent to and are at higher elevations than produce fields.”
FDA has made several recommendations to help bolster food safety in an attempt to prevent future outbreaks. The FDA is encouraging a redoubling of preventative efforts within the leafy greens industry, with more focus placed on adjacent land use and increasing buffer zones when cattle operations are nearby. Other recommendations include improving the security of safe water supplies and increasing digital documentation to improve traceability.
While no fatalities were reported, the outbreaks which occurred last November and December sickened 188 individuals and affected people in at least 16 states and Canada. In relation to the number of outbreaks associated with leafy greens in recent years, the FDA has detailed an action plan for addressing the problem moving forward.