FDA Closes the Book on the Listeria Outbreak Linked to Salad - December 2021

FDA said the the December 2021 Listeria outbreak linked to Dole vegetable salad products is officially over.  In this outbreak, there were a "total of 18 people infected with the outbreak strain of Listeria monocytogenes were reported from 13 states".  

The "investigation conducted by Dole detected the presence of Listeria on a piece of equipment in their Yuma, AZ, facility. FDA conducted WGS analysis of an isolate shared by Dole, and the results confirmed that this isolate of Listeria matched the strain causing illness in this outbreak and also matched the strain of Listeria found in a positive product sample collected by the Michigan Department of Agriculture and Rural Development, as reported on December 23, 2021. Dole decommissioned and later dismantled this piece of equipment."

Additionally, as "reported on February 1, 2022, following the initial voluntary recall issued by Dole on December 22, 2021, Dole detected the presence of Listeria monocytogenes on equipment used in the harvesting of the iceberg lettuce that was also used in finished products processed in the Dole Springfield, OH, and Soledad, CA, facilities. This finding prompted a subsequent voluntary recall on January 7, 2022"

"FDA analyzed the positive samples collected by Dole from the harvesting equipment. Results from FDA’s Whole Genome Sequencing (WGS) analysis showed that the strain of Listeria found on the harvesting equipment matched the strain causing illnesses in this outbreak. Dole decommissioned the harvester and it was later dismantled. Product on hold that was included in the December 2021 recall was later tested by Dole and tested positive for the strain of Listeria monocytogenes that caused illnesses in this outbreak."


https://www.fda.gov/food/outbreaks-foodborne-illness/outbreak-investigation-listeria-monocytogenes-dole-packaged-salad-december-2021
Outbreak Investigation of Listeria monocytogenes: Dole Packaged Salad (December 2021)

FDA’s investigation is complete. CDC declares outbreak over.

The FDA, along with CDC and state and local partners, investigated a multistate outbreak of Listeria monocytogenes infections linked to Dole packaged leafy greens. A total of 18 people infected with the outbreak strain of Listeria monocytogenes were reported from 13 states. According to the CDC, as of April 4, 2022, this outbreak has ended.

FDA sent investigators to multiple Dole processing facilities to conduct on-site inspections and Dole conducted a root cause analysis of their own in an effort to determine the potential source of contamination for this outbreak. Continued investigation conducted by Dole detected the presence of Listeria on a piece of equipment in their Yuma, AZ, facility. FDA conducted WGS analysis of an isolate shared by Dole, and the results confirmed that this isolate of Listeria matched the strain causing illness in this outbreak and also matched the strain of Listeria found in a positive product sample collected by the Michigan Department of Agriculture and Rural Development, as reported on December 23, 2021. Dole decommissioned and later dismantled this piece of equipment.

As reported on February 1, 2022, following the initial voluntary recall issued by Dole on December 22, 2021, Dole detected the presence of Listeria monocytogenes on equipment used in the harvesting of the iceberg lettuce that was also used in finished products processed in the Dole Springfield, OH, and Soledad, CA, facilities. This finding prompted a subsequent voluntary recall on January 7, 2022.

FDA analyzed the positive samples collected by Dole from the harvesting equipment. Results from FDA’s Whole Genome Sequencing (WGS) analysis showed that the strain of Listeria found on the harvesting equipment matched the strain causing illnesses in this outbreak. Dole decommissioned the harvester and it was later dismantled. Product on hold that was included in the December 2021 recall was later tested by Dole and tested positive for the strain of Listeria monocytogenes that caused illnesses in this outbreak.

During the investigation, operations at the Bessemer City, NC, and Yuma, AZ, facilities were temporarily halted for deep cleaning, sanitization, and verification swabbing, and have since resumed.

Epidemiologic, laboratory, and traceback data indicated that leafy greens produced by Dole were the source of this multistate outbreak. Dole cooperated with FDA inspectors, undertook a root cause analysis, and shared results of its root cause analysis with FDA. FDA plans to continue to work with industry, federal partners, state and local regulators, academia, and others to address the safety of leafy greens by advancing work in prevention, response, and addressing knowledge gaps.

Recommendation

On April 4, 2022, CDC announced this outbreak is over. The product is past expiration and is no longer available to consumers. Therefore, there are no specific recommendations for consumers, retailers, or suppliers.

In general, FDA recommends that anyone who received recalled products use extra vigilance in cleaning and sanitizing any surfaces and containers that may have come in contact with these products to reduce the risk of cross-contamination. Listeria can survive in refrigerated temperatures and can easily spread to other foods and surfaces.