FDA Investigation Reveals Likely Causes of Listeria Outbreak

In the Oct. 12 edition of The Watcher, we highlighted the multi-state listeriosis outbreak as an example of the high stakes of food safety regulation. Linked to cantaloupes from Colorado-based Jensen Farms, the deadliest foodborne disease outbreak in a decade has now killed 25 people. This week, the U.S. Food and Drug Administration (FDA) released a report from an investigation conducted in conjunction with the Centers for Disease Control and Prevention (CDC) that reveals some of the factors potentially contributing to the listeria contamination.

FDA’s "Environmental Assessment" included interviews with Jensen Farms management, on-site visits to the fields and facilities, and product sampling. The assessment concluded that facility design, equipment design, and post-harvest practices may have contributed to the growth and spread of the contamination. In addition, issues at the packing facility and cold storage were identified as the factors that most likely contributed to the contamination of the fresh cantaloupe. For example, the assessment found that the design of the facility allowed water to pool on the floor, that the "floor was constructed in a manner that was not easily cleanable," and that "the packing equipment was not easily cleaned and sanitized."

To prevent future contamination, FDA recommended that industry use good agricultural and management practices set out in the "Guide to Minimize Microbial Food Safety Hazards for Fresh Fruits and Vegetables," produced by the FDA and the U.S. Department of Agriculture. The recommendations also emphasized that good practices should be used in packing facilities, as well as growing fields.

On Oct. 18, FDA sent Jensen Farms a warning letter listing violations found during the inspections and the locations within the facilities that tested positive for outbreak strains of listeria. The letter cautioned that FDA may take further action if Jensen Farms does "not promptly correct these violations," including seizing products or enjoining the company from continuing operations.

As investigations help shed light on the causes of contamination, regulators must be able to ensure that all food producers are consistently implementing the most protective safety and prevention practices available. The public should not have to worry that the next bite of cantaloupe, spinach, lettuce, hamburger, turkey, or other food could lead to severe illness or death from a foodborne illness.

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