Positive Environmental Samples Found at Taylor Farms of Mexico

After the outbreak ended, FDA continued to conduct environmental sampling at several farms in Mexico and a Taylor Farms of Mexico processing facility. Traceback evidence indicated these locations provided the implicated lettuce distributed by Taylor Fresh Foods. Sampling included water, soil, sediment, and lettuce.

The agency found two positive samples: one from a tank that held outgoing wastewater from the Taylor Farms of Mexico processing facility, and another collected from a drainage ditch of an iceberg lettuce grower identified in FDA’s traceback. Genotyping for these positive samples has been completed, and FDA is continuing its analysis to determine how the environmental isolates may relate to isolates from outbreak patients.

Root Cause of Contamination Remains Unsolved

FDA was unable to gather enough evidence to conclusively determine the root cause of contamination at the locations that grew and processed the implicated lettuce. However, the agency said that the positive environmental samples add to the strong epidemiological data and traceback convergence supporting the link between the cyclosporiasis outbreak and recalled shredded iceberg lettuce from Taylor Farms of Mexico.

FDA Announces Ten Actions to Prevent Future Cyclospora Outbreaks

Following the historically large outbreak, as well as several other, smaller cyclosporiasis outbreaks that happened this summer, FDA has announced ten planned activities to prevent future cyclosporiasis outbreaks.

• Publishing an Outbreak Investigation Report, which will summarize the outbreak investigation, review the potential factors contributing to the contamination of imported, shredded iceberg lettuce by Cyclospora, and provide recommendations to help prevent future outbreaks
• Increasing surveillance of commodities historically associated with Cyclospora and their production to better inform the understanding of contamination levels and effective sampling strategies
• Conducting more outreach and public engagement domestically and abroad to raise awareness of current and prospective food safety requirements, such as the Produce Safety Rule, the Preventive Controls for Human Food Rule, and the Food Traceability Rule, and helping to ensure that growers adopt effective practices that reduce the risk of Cyclospora in produce for American consumers
• Enhancing laboratory capacity in Mexico to collect, analyze, and process samples for Cyclospora investigations in-country, reducing the time needed to get final laboratory analyses
• Leveraging new and alternative data sources and tools to monitor environmental factors that may lead to Cyclospora proliferation, such as weather events, to determine whether such factors are an indicator of potential issues and potentially inform future prevention strategies
• Collaborating with Mexican agencies including the Ministry of Agriculture, the Federal Commission for the Protection Against Sanitary Risks (COFEPRIS), and the National Service of Public Health, Safety and Quality of Agri-Food (SENASICA) to expand food safety education and training opportunities related to Cyclospora prevention practices for Mexico’s fresh produce industry
• Convening expert panels on worker health and hygiene, water and wastewater monitoring, and gaps that need to be addressed to improve growing and processing practices for certain fresh produce, with the intent of directly targeting the conditions most likely to introduce Cyclospora into the fresh produce supply
• Working with CDC to enhance and align genotyping methods for Cyclospora, with the goal of creating a single, replicable standard within the federal government, with partner nations, across industry to make it faster and easier to trace outbreaks back to their source
• Increasing and further leveraging Foreign Supplier Verification Program (FSVP) inspections to help ensure that importers are considering Cyclospora contamination as a part of their hazard analysis and supplier verification to ensure imported fresh produce meets U.S. safety standards
• Taking lessons learned from the investigation and any root cause analysis of this specific outbreak to update the Cyclospora Prevention, Response and Research Action Plan with longer-term prevention, response, research, and programmatic activities, laying the groundwork for stronger prevention and response in future growing seasons.

FDA will undertake these activities now, ahead of the 2027 growing season.