Earlier this year, we experienced the largest E. coli O157:H7 outbreak the country has seen in the last decade, leaving hundreds sick and claiming the lives of five people who consumed contaminated romaine lettuce.
We’re committed to taking necessary actions to prevent future outbreaks like this and to improving the safety of leafy greens available in the marketplace. Since the next romaine growing season for the Yuma region is underway, it’s critical for all of us to understand what happened so we can identify the changes that can prevent future outbreaks and reduce the scope of any problems that could arise.
Since the first signs of the outbreak appeared, our team has collaborated closely with our state, federal and local partners to determine the root cause of the outbreak. Today, the U.S. Food and Drug Administration is sharing an environmental assessment that details final findings from this investigation.
One of the investigation’s main objectives was to identify factors that potentially contributed to the introduction and spread of the strain of E. coli O157:H7 that contaminated the romaine lettuce associated with this outbreak. The FDA, the Centers for Disease Control and Prevention, and the Arizona Department of Agriculture launched an investigation of the outbreak, leading to the collection of samples in Yuma in order to help gather evidence needed to identify the source of the outbreak.
The environmental assessment issued today confirms the presence of E. coliO157:H7 in three samples of irrigation canal water collected as part of this investigation in the Yuma region. It considers that the most likely way the romaine lettuce became contaminated was from the use of water from the irrigation canal, since the outbreak strain was not found in any of the other samples collected in the region. How the water contaminated the lettuce is uncertain. But based on interviews with growers and pesticide applicators, possible explanations include direct application of irrigation canal water to the lettuce crop or the use of irrigation canal water to dilute crop-protection chemicals applied to the crops through both aerial and land-based spray applications. We cannot rule out other ways the lettuce became contaminated. It’s important to note that we have no evidence that any other product grown in Yuma was contaminated by this water.
When and how the irrigation canal became contaminated with the outbreak strain of E. coli O157:H7 is also uncertain. We know that a large concentrated animal feeding operation (CAFO) is located adjacent to this stretch of the irrigation canal where the samples were collected. This is one potential source. However, the investigation did not identify an obvious route for contamination of the irrigation canal from this facility. In addition, samples collected at the CAFO did not yield E. coli O157:H7. The investigation did not exclude other ways the irrigation canal could have become contaminated with this outbreak strain.
With the growing season underway in Yuma, we know just how important it is to continue collaborating closely with industry and our regulatory partners to ensure that leafy greens are safe. To assist with these efforts, our environmental assessment recommends a number of steps that can be taken to reduce the likelihood of another tragic outbreak from occurring in the future. Working with the produce industry to further reduce the risk of outbreaks is a key priority for the FDA.
Fully implementing the Food Safety Modernization Act (FSMA) is critical to these efforts. We must continue to advance FSMA’s Produce Safety Rule in collaboration with our state regulatory partners and ensure that we craft agricultural water standards that work across the incredible diversity of commodities and growing conditions. The FDA has resources available to help industry comply with FSMA requirements, including produce safety experts regionally located as part of the FDA’s Produce Safety Network and growers in the Yuma region can find the contact information for their area at this website.
Because leafy greens are a highly perishable commodity, the ability to traceback the route of a food product as it moves through the entire supply chain, or traceability, is critical to removing the product from commerce as quickly as possible, preventing additional consumer exposures, and properly focusing any recall actions. During the romaine investigation we found the typical traceback process to be particularly challenging because much of the finished lettuce product contained romaine that was sourced from multiple ranches As a result, our investigation involved collecting documentation from each point in the supply chain to verify the movement of product back to the Yuma area. Complicating this already large-scale investigation, the majority of the records collected in this investigation were either paper or handwritten.
Going forward, both FDA and industry need to explore better ways to standardize record keeping and determine whether the use of additional tools on product packaging could improve traceability.
We strongly encourage the leafy greens industry to adopt traceability best practices and state-of-the-art technologies to help assure quick and easy access to key data elements from farm to fork. We also strongly encourage the leafy greens industry to explore modern approaches to standardized record keeping and the use of additional tools or labels on product packaging that could improve traceability. We urge all segments of this industry and our government partners to review the findings of our environmental assessment and make necessary changes. For our part, the FDA is exploring ways to best tap into new technologies to significantly reduce the time needed for traceback investigations.
The agency is taking steps to improve our response times and provide actionable information to consumers as quickly as possible. We are also looking at our regulatory options and considering appropriate enforcement actions against companies and farms that grow, pack, or process fresh lettuce and leafy greens under insanitary conditions. We continue to explore additional ways to improve these processes and urge all segments of the leafy greens industry to review their operations in the same way.
As a next step, the FDA plans to collect and analyze romaine lettuce samples through a new special surveillance sampling assignment for contamination with human pathogens. This will help us determine whether products are safe to enter the U.S. marketplace. If samples are found to be contaminated, the FDA will follow-up with fresh-cut leafy greens processors and their growers or suppliers to determine if these foods were produced under insanitary conditions that render them harmful to consumers and take the appropriate action to remove them from the market.
We recognize and appreciate the efforts that the leafy greens industry has taken to date. But we know more must be done on all fronts to help prevent future foodborne illness outbreaks. I remain committed to investing in the FDA’s food program and applying our food safety expertise as we work to better safeguard the U.S. food supply. We want food to be safe because it promotes the American industries that grow and produce these products. That’s part of our dedication to these efforts. But first and foremost, we pursue food safety measures as key parts of our public health mandate to protect American consumers