Listeria outbreak linked to Dole bagged salads traced back to equipment
The FDA, CDC and local partners have concluded their investigation of a listeria outbreak linked to Dole packaged salads in late 2021.
A total of 18 people infected with the outbreak strain of Listeria monocytogenes were reported from 13 states. The CDC declared the outbreak over as of April 4, 2022.
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 its Yuma, Arizona facility. The FDA conducted Whole Genome Sequencing (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 Dec. 23, 2021. Dole decommissioned and later dismantled this piece of equipment.
As reported Feb. 1, following the initial voluntary recall issued by Dole on Dec. 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, Ohio and Soledad, California facilities. This finding prompted a subsequent voluntary recall on Jan. 7, 2022.
FDA analyzed the positive samples collected by Dole from the harvesting equipment. Results from FDA’s 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, North Carolina and Yuma, Arizona facilities were temporarily halted for deep cleaning, sanitization, and verification swabbing. Operations 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.
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.
