The U.S. Food and Drug Administration (FDA) announced on October 2, 2026, that it had concluded its investigation into the Cyclospora outbreak linked to iceberg lettuce sourced from Central Mexico.
Investigation Update
In the Oct 2nd announcement, the FDA shared that they had conducted an onsite inspection and sample collection (water, soil, sediment, and lettuce) at several farms and facilities in Mexico. The FDA reported that two positive environmental samples collected during inspections in Mexico: one from a tank holding outgoing wastewater at the processing facility and another from a drainage ditch at a lettuce grower identified through traceback. The total number of samples taken was not shared by the FDA.
FDA noted that these findings confirm Cyclospora was present in the environment where lettuce was grown and processed. While they do not conclusively establish how contamination occurred, they mention this adds to the strong epidemiological and traceback evidence linking the outbreak to recalled shredded iceberg lettuce. Genotyping of both positive environmental samples has been completed, and FDA is continuing its analysis to determine how those results relate to ongoing genotyping of clinical specimens.
What Happens Next?
The FDA’s post-outbreak response page shares what is happening next, they have two types of actions (i) Immediate and (ii) ahead of the 2027 sessions. Immediate actions included that During the week of September 8, FDA met with senior Mexican public health and agricultural officials to discuss recent outbreaks and strengthen prevention efforts. The agency also sent a letter to industry calling for collaboration to address Cyclospora contamination throughout the supply chain. Work to understand the outbreak’s root cause continues, and they have committed to sharing those findings and incorporate lessons learned to their cyclospora prevention, response and research action plan.
Ahead of the 2027 growing season, FDAs also listed 10 activities that reflect their plans to mitigate risk during the 2027 season. These include
- Publishing an outbreak investigation report
- Expanding surveillance of commodities historically associated with Cyclospora.
- Conducting outreach activities, domestically and internationally on PSR, Preventive Controls and the Traceability Rule
- Strengthening laboratory capacity in Mexico and aligning genotyping methods with CDC.
- Leverage data to monitor environmental and weather factors as potential indicators of contamination risk.
- Collaborating with Mexican authorities to expand food safety education and training.
- Convening experts on worker health and hygiene, water and wastewater monitoring, and growing and processing practices.
- Increasing Foreign Supplier Verification Program inspections to assess how importers address Cyclospora hazards.
- Taking lessons learned and incorporating them into the Cyclospora Prevention, Response and Research Plan
What Are Mexican Authorities Saying?
Mexican federal and state authorities also addressed FDA’s findings. In an October 3, 2026, informational statement, COFEPRIS responded to the closure of the Cyclospora and Salmonella Javiana investigations. According to reporting reproducing the statement, COFEPRIS acknowledged FDA’s two positive Cyclospora environmental samples but emphasized that those findings alone did not conclusively establish agricultural products as the source of contamination. The agency also cited negative results from Mexican testing of raw material, finished product, and water. The statement also reaffirmed its commitment to continued technical and scientific cooperation with FDA and CDC.
In a separate release issued the same day, the Government of Guanajuato acknowledged FDA’s investigation closure and outlined continued coordination through its Secretaría del Campo. The state said it remained in communication with SENASICA and the company to review available technical evidence and determine appropriate preventive and follow-up actions.
Guanajuato also described ongoing collaboration with the Comité Estatal de Sanidad Vegetal de Guanajuato (CESAVEG), producers, and companies to strengthen monitoring, traceability, and food safety practices. The state reaffirmed its commitment to cooperate with authorities in countries receiving its agricultural exports, in coordination with Mexican institutions and based on scientific evidence.
Additional Information
For more information, visit Western Growers’ Cyclospora resource page for the fresh produce industry. Additional reading includes:
For questions or additional support, contact Gustavo Reyes at [email protected], Joelle Mosso at [email protected], or De Ann Davis at [email protected].
