To develop and implement effective food safety processes and practices, it is necessary to understand the root causes of potential food contamination and foodborne-illness outbreaks. But, too often, just as we think we are getting it figured out, a new pathogenic strain emerges, a product that has not previously had issues is determined to be the cause of an outbreak; or, simply, no one can seem to get to the root of a problem – novel or ongoing. This has been shown quite clearly with the recent Salmonella outbreaks that were linked to peaches and onions. To the best of my knowledge, Salmonella outbreaks have never been associated with either of these foods in the past. While outbreaks related to such products are not entirely unheard of due to other pathogens, they are rare enough to not be one’s first thought in an outbreak and to require new thinking for prevention. And it is, in fact, a global problem. As stated in a publication from the World Health Organization, “There are many reasons for foodborne disease remaining a global public health challenge. As some diseases are controlled, others emerge as new threats.” Unfortunately, though, the challenge does seem to significantly impact produce. And that has led to an increased focus by FDA on both the impact of animal operations in close proximity to growing fields and a California- and Arizona-based leafy greens sampling strategy. In late May, FDA released the findings of an investigation into three outbreaks of E. coli O157:H7 illnesses that occurred in Fall 2019, all tied to romaine lettuce, suggesting that the proximity of cattle to produce fields may have been a contributing factor. This is based on investigation samples in which:
- One of the outbreak strains of E. coli O157:H7 was detected in a sample taken from a cattle grate on public land less than two miles upslope from an implicated produce farm.
- Four samples had other Shiga toxin-producing strains of E. coli (STEC): two were taken from the border area of a farm next to cattle grazing land in the hills above leafy greens fields; and two were from on-farm water drainage basins. Although these strains were not tied to the outbreaks, FDA feels they “offer insight into the survival and movement of pathogens in this growing region.”
- Will work with stakeholders to share knowledge on new technologies and sampling approaches that increase the ability to detect STEC, to enable more effective industry sampling and testing.
- Initiated a year-long program to test for disease-causing strains of E. coli and Salmonella in romaine samples collected after harvest but before processing.
- Has, with the University of Arizona, produce growers, and local irrigation water authorities, started a multi-year study to understand how disease-causing E. coli and other pathogens could reach leafy greens in fields near Yuma, Arizona.