Salmonella Outbreak Linked to Cucumbers

An outbreak of 196 Salmonella infections across 28 states is linked through epidemiological data to cucumbers grown in Florida. Currently, Salmonella Africana is considered the outbreak strain. However, CDC and FDA are investigating an outbreak with similar onset times and demographics involving 185 illnesses from Salmonella Braenderup to determine if it is also linked to the same cucumbers. The recalled cucumbers were shipped in bulk cartons directly to retail distribution centers, wholesalers, and food service distributors in AL, FL, GA, IL, MD, NC, NJ, NY, OH, PA, SC, TN, VA, and WV from May 17th through May 21st, 2024.

As part of the investigation, the Pennsylvania Department of Agriculture collected samples of cucumbers from several retail locations in their state and found that one sample tested positive for Salmonella. However, the strain was identified as Salmonella Bareilly, a different strain of Salmonella than the one making people sick in this outbreak and one that does not match any ongoing outbreaks.

Salmonella outbreaks involving cucumbers are not uncommon as shown in the table below. Four other outbreaks have been linked to cucumbers in the U.S. since 2013. The largest of these involved Salmonella Poona traced to cucumbers from Baja, Mexico which resulted in 907 illnesses. An onsite inspection of the grower and packing facility in Mexico revealed potential sources and routes of contamination, including concerns with wastewater management, equipment design of the flume handling system area, and storage of packing materials. However, environmental samples were not collected, and the root cause of the outbreak was not determined. The firm involved was put on Import Alert.

The Salmonella Poona outbreak resulted in FDA conducting cucumber microbiological surveillance sampling in 2016–2017. Samples (n=1601) were analyzed for Salmonella spp. and E. coli O157:H7 to determine prevalence in both imported (76%) and domestic (24%) cucumbers. The sampling strategy reflected the U.S. market share of each growing region and was designed to detect contamination levels of one percent or greater. Salmonella was detected in 1.75% of the samples collected. E. coli O157:H7 was not detected in any samples.

Salmonella contamination on the skin of cucumbers can result from soil amended with untreated biological material from animal origin or irrigation water contaminated with fecal material, especially from run-off. Surface water used for overhead irrigation is also a source. Cross-contamination during harvesting, packing, and further processis also a potential hazard. FDA provides guidance on safe handling of raw produce for shippers and carriers, retailers, and consumers on their website.