As a food safety lawyer, I enjoy reviewing recall statistics to see how the food industry is doing overall at avoiding large-scale recalls. So far this year, the industry has done a remarkable job with E. coli. To date, I count only a small number of recalls involving a very small amount of product. When it comes to Listeria, however, the statistics are quite different. Since January, there have been a large number of recalls for Listeria monocytogenes involving nearly 50,000,000 pounds.

The jump in recalls for meat and poultry products comes at the same time there is a substantial increase in Listeria recalls of other products as well. Cheese, caramel apples, ice cream, packaged salads, frozen vegetables and sunflower kernels have all been implicated in recent large-scale recalls. What’s notable in each of these cases, is that the manufacturers were all testing for and periodically finding Listeria in their processing environments. Although each of the companies involved were also performing a “root cause” analysis (and implementing corrective actions) to address each of those findings, in every case their approach absolutely failed to prevent direct product contamination and a massive recall.

So, what went wrong? Well, too many companies define the “root cause” of a positive listeria finding as the failure to adequately clean the area that sampled positive. In response, those companies implement corrective actions that call for: (1) intensified cleaning and sanitization of the area in question; (2) in most cases retesting of the sampled area; and (3) employee retraining. If this is your approach to positive environmental samples, then your products will likely be listed next on the growing list of food products being recalled. What this approach fails to consider, and which can and will be deadly to any company, is the “root source” of the Listeria that made its way into the drain in the first instance.

Low levels of Listeria in the processing environment can easily find harborage and sporadically contaminate food products over prolonged periods of time. With all the work FDA is now doing conducting extensive microbiological sampling in food facilities during routine inspections (taking as many as 300 samples during a single visit), the agency is confirming that, once introduced, Listeria can become and remain extremely resilient in the production environment. Unless adequately controlled, it can elude most attempts at detection, and contaminate small amounts of product over long periods of time. This is what was happened to Blue Bell, Dole and CRF, and which is happening in countless other food processing facilities whose sporadically contaminated products, at least to date, have avoided detection.

What does this mean for food companies? In the event of a positive, the past practices of re-cleaning, re-sanitizing, re-testing, and resuming (production) are over. Food companies cannot continue to ignore sporadic or intermittent positive findings. Although many food companies view an outbreak as something that will be caused by a single operational failure (which will be obvious and limited in scope when it occurs), the reality is that the culprit is in most cases something far more subtle, far more persistent, and far more dangerous. If you find Listeria in the environment, you need to conduct more than a “root cause” analysis; you need to conduct a “root source” analysis to help identify and then eliminate the original source of the Listeria that made its way into your facility. If you don’t, the Listeria that found its way into your drains will just as easily find its way into your product.