Listeria monocytogenes, the same bacteria that was at the center of 2015’s national recall of Blue Bell ice cream, is returning to the forefront of the food safety conversation, this time due to a contamination of Dole packaged salad products. As of the time of this writing, 15 people (one of whom has died) in eight states and seven others in Canada have been stricken with Listeria connected directly to salad products manufactured at Dole’s Springfield, Ohio facility. Dole has temporarily suspended operations at the Springfield location and issued a voluntary recall on salad products that were manufactured there. These products can be easily identified by the letter “A” at the beginning of manufacturing code on the package, as indicated in the sample image to the right.

An especially resilient organism, Listeria is effective in cold, wet environments, which are prevalent in food processing facilities that contain washing lines for products and large, refrigerated spaces. If Listeria is allowed to remain in an area for an extended period of time, it will generate its own bio-film, becoming even more difficult to remove. Once the bacteria infects a host, it does not make itself immediately known, with symptoms taking anywhere from three weeks to two months to materialize. This only exacerbates the difficulty in tracing the problem to its source.

This latest outbreak, coming just as Blue Bell is finally starting to return to normalcy after last year’s headline-grabbing mass recall, is a significant reminder of how food safety issues can impact even the largest manufacturers. Facilities must adhere to strict cleaning regimes in order to combat Listeria and other bacteria. Extending beyond a plant’s policies and procedures, hygienic concerns can have a direct effect on physical layout, as well; a location must be designed in a manner that allows easy cleaning access to any and all areas that have direct contact with food products.

No sanitation program can be 100% effective, and the reality is that food products, especially fresh produce, will introduce unwanted pathogens into a facility at some point. The second key component of maintaining a hygienic processing environment, then, is the presence of a thorough testing program that can quickly identify sources of contamination so that the problem may be eliminated before it escalates in severity. With first Blue Bell and now Dole being impacted by the severe consequences of Listeria, it remains to be seen what steps other food manufacturers will take to prevent a similar outcome.

For Dole’s response to the outbreak and information on the company’s voluntary recall, please click here.