The U.S. Food and Drug Administration this month released its first domestic investigation of a foodborne illness outbreak associated with leafy greens grown in a Controlled Environment Agriculture (CEA) operation.

The outbreak, with cases reported from June 10, 2021 to August 18, 2021, was caused by Salmonella Typhimurium and resulted in 31 illnesses and four hospitalizations. The FDA did not identify the specific source or route of contamination during the investigation, but did identify conditions that may have contributed to product contamination. Those included:

• Raw materials (nutrient-rich growth media) stored outdoors without adequate protection.
• Indoor ponds used to grow plants – sanitation practices, procedures and records inadequately documented.
• Pond water tested positive Salmonella Liverpool, a strain not associated with the outbreak.
• Facility and equipment design – harvest equipment did not exclude leaves which may have contacted pond water. Overhead condensate dripping on product and on conveyor belts.
• A stormwater retention pond approximately 25 feet from the CEA tested positive for the outbreak strain of Salmonella Typhimurium.

Although indoor hydroponic agriculture differs from open field agriculture in many ways, FDA concluded that many contamination risk factors are similar to those found in traditional, open field agriculture. Therefore, FDA highlighted the following requirements and recommendations for CEAs:

1. Assess and understand potential sources and routes of contamination within and around your operations, including adjacent and nearby land use that may impact CEA operations.
2. Implement effective sanitation procedures and sampling plans, including hygienic operations and equipment design, ensuring cleaning procedures (such as use of high-pressure water) do no disperse microbial contaminants which may be present.
3. Apply science and risk-based best practices aligned with the Food Safety Modernization Act (FSMA) Produce Safety Rule and good agricultural practices (GAPs).
4. Maintain proper temperature in cooling and holding areas and monitor processing and storage environments as well as product temperatures to prevent pathogen growth.
5. Ensure all water used in the operation is of adequate water quality for intended use, including pond water.
6. Perform root cause analysis (RCA) when pathogens are detected to determine how contamination likely occurred and to implement appropriate preventive measures.

Western Growers Root Cause Analysis offerings fall into three categories: 1) a fresh produce specific RCA guidance, 2) RCA training and education, and 3) RCA consultation services to help you conduct root cause analysis in your operations. For more information, please contact Afreen Malik at [email protected].