Listeria: What food processors need to know

Listeria is a genus of bacteria commonly found in soil and water that has the potential to be found in food processing plants. Contamination with Listeria is one of the biggest food safety concerns that food producers and processors face. When consumed, the pathogenic strain of the bacteria, Listeria monocytogenes, causes listeriosis, a potentially serious form of food poisoning. An estimated 1,600 people in the U.S. contract listeriosis each year, and approximately 260 cases are fatal, according to the Centers for Disease Control and Prevention.

If you’re a food processor, there’s a good probability that Listeria is present somewhere in your facility. The best course of action is to manage it.

Why control Listeria?

Transient Listeria is commonly found in most environments, including your home. The goal of a processor is to prevent it from becoming a permanent resident, infecting products and causing illness to customers. If Listeria contaminates a product, there can be serious consequences, including millions of dollars in direct costs, loss of contracts and partner relationships, and a damaged brand reputation.

Where to test for Listeria

Since Listeria can be found just about anywhere, it’s important to be thorough with testing. When testing environmental surfaces, Zone 1 areas (such as conveyers, slicers, dicers, blenders, etc.) should be tested. While U.S. Food and Drug Administration guidance recommends Zone 1 testing, areas in Zone 3 (such as drains, floors, bases of equipment, etc.) should also be tested.

Training and proper cleaning techniques are instrumental to avoiding Listeria contamination, as improper cleaning methods have been known to allow the transfer of Listeria from Zone 3 to Zone 1 (examples include: backsplash from a high water pressure, tracking via employees or relocated equipment, etc.).

Ultimately, by testing Zones 1 through 3 frequently, thoroughly, and with proper methods, food processors stand the best chance at protecting customers and themselves from a Listeria outbreak.