Dangerous E. coli bacteria that caused three foodborne illness outbreaks in late 2019 most likely came from cattle that grazed near fields of romaine lettuce or leafy greens, according to a recent U.S. Food and Drug Administration report. FDA’s findings make clear that growers, ranchers, and local, state, and federal agencies must work together to prevent contamination of leafy greens by pathogens commonly present in animal fecal matter. This food safety problem cannot be solved by a single industry or regulatory authority.
Public health officials linked the three outbreaks—each caused by a different strain of E. coli O157:H7—to romaine lettuce or salad mixes, and traced these products to several fields in California’s Salinas Valley. According to FDA’s report released in May, investigators found the E. coli strain from the largest of the outbreaks in a sample of fecal and soil matter taken from a cattle grate within 2 miles of multiple fields where romaine had been grown. Other harmful strains unrelated to the 2019 outbreaks turned up in samples taken from an area between fields and grazing land and from on-farm water drainage basins.
This is not the first time that cattle have been implicated as a likely source of produce contamination. A feedlot with tens of thousands of animals adjacent to an irrigation canal used by farms in Yuma, Arizona, was the possible source of E. coli in a 2018 outbreak also linked to romaine. FDA’s investigation in the Salinas Valley highlights that much smaller herds also can pose contamination risks for nearby produce operations.
The FDA report makes clear that allowing cattle to graze near fields that grow romaine lettuce or other leafy greens creates an unacceptable risk to the health of consumers, who often eat these foods raw. The question is how best to reduce this danger.
The report recommends that growers “redouble” prevention efforts, “assess and mitigate risks associated with adjacent and nearby land uses,” and create buffer zones between fields and grazing lands as well as physical barriers to divert water runoff away from crops. An FDA action plan detailed agency efforts to reduce outbreaks linked to leafy greens, including plans to complete its report on the Salinas investigation and release revised standards for the quality of water used in produce operations.
These steps are necessary but not sufficient to effectively address this situation. Although the agency oversees produce safety, it does not regulate livestock operations; in fact, no federal agency does.
The solution to a complex problem like this one requires a multidimensional approach. For example, a wide range of stakeholders could be brought together to develop a coordinated plan to address risks created when produce and animal agriculture businesses are located near one another. Produce farmers and cattle ranchers should be at the table, along with federal, state, and local authorities.
State and local authorities have jurisdiction over land use, whether for cattle grazing or other activities. That’s why agencies at those levels need to consider adjacent land use when allowing cattle to graze on a particular property and put in place appropriate requirements and restrictions.
The U.S. Department of Agriculture does not have jurisdiction on the farms, ranches, and feedlots where cattle are raised; its oversight of meat and poultry safety begins when the animals are slaughtered and processed into products such as steaks and ground beef. However, the department does run programs that provide financial assistance to growers and ranchers that, for example, take steps to address natural resource and environmental concerns.
USDA should evaluate whether these programs could help livestock operations to control fecal contamination from cattle more effectively. If existing programs do not allow for such incentives, then the department should consider establishing ones that do.
FDA should lead an effort to find comprehensive solutions to the public health problems created when cattle and produce farms operate in proximity. Without such solutions, Americans may see still more outbreaks linked to romaine lettuce and other leafy greens in the years ahead.
Sandra Eskin directs The Pew Charitable Trusts’ work on food safety.
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