The U.S. Food and Drug Administration (FDA) is launching an assignment to collect romaine lettuce samples from commercial coolers in the Yuma County, Arizona growing region during the current harvest season. The samples will be tested for Shiga toxin-producing Escherichia coli and Salmonella spp. as part of ongoing surveillance efforts  following the spring 2018 multistate E. coli O157:H7 outbreak of foodborne illness linked to romaine lettuce from the Yuma agricultural region. Salmonella spp. also commonly causes foodborne illness outbreaks in the United States, which have at times been linked to romaine lettuce consumption.

The FDA plans to begin collecting samples of romaine lettuce from commercial coolers in February and intends to continue sampling through the end of the romaine harvest season in Yuma. The FDA assignment will focus on commercial cooler and cold storage facilities where field heat is removed from harvested romaine and where product is cold stored before processing and shipment. The focus on these sites enables the FDA to efficiently collect samples from multiple farms at centralized locations, following  a similar model used during an assignment conducted in FY19.

The agency plans to collect and test approximately 500 samples of romaine lettuce for this assignment. Each sample will consist of 10 subsamples, and each subsample will be made up of at least 300 grams of romaine lettuce (whole heads, hearts or individual leaves). All samples will be collected prior to processing of the lettuce as well as prior to any handling by workers at the cooling and cold storage facilities. 

The FDA has contracted with an independent laboratory located in Arizona near the collection sites to test the samples. Using this laboratory will help to greatly reduce the time between sample collection and the reporting of the results. The FDA expects to receive test results within 24 hours of the laboratory receiving the samples, which will then be relayed to the firms. FDA understands that industry may choose to hold the sampled lots pending notification of test results to help prevent potential recalls of any contaminated lettuce that could have entered commerce.

During this sampling assignment, the FDA will take extra precautions to help ensure the safety of agency investigators and firm employees during the coronavirus pandemic. FDA investigators will preannounce their visits to firms and will be outfitted with personal protective equipment and otherwise equipped to carry out their work while adhering to state and local guidance as well as applicable U.S. Centers for Disease Control and Prevention guidance.

Helping ensure the safety of leafy greens continues to be a priority of the FDA. This assignment adds to other work underway in collaboration with stakeholders in the Yuma agricultural region to implement actions identified in the Leafy Greens Action Plan, including a multi-year study to assess the environmental factors that impact the presence of foodborne pathogens in this region. Consistent with the action plan, the agency will engage with industry on conducting root cause analyses for any positive samples found during this assignment. Root cause analyses are important in that they seek to identify potential sources and routes of contamination, inform what preventive measures are needed, and help prevent outbreaks of foodborne illness.