There have been three recalls in the last few days of food due to the possibility of contamination with Listeria monocytogenese. This includes a long list of wraps, salads, humus and sandwiches from a Californian firm when Listeria was found in the manufacturing plant; corn and poblano peppers from a firm in Washington state when Listeria was found through company testing, and alfalfa sprouts and sprout salad in the North Eastern United States when Listeria was found in a retail sample. Each of these recalls was triggered by testing at different places in the supply chain – the manufacturing facility, company testing of product and testing at retail.

Both State and Federal regulators are increasing the amount of testing they are doing during inspections in manufacturing facilities and at retail operations (for example in retail stores that operate a deli) and at in foods being sold at retail. This strategy is being driven heavily by the recognition that many companies do not have adequate environmental controls in place and are not monitoring the manufacturing and processing environment adequately. While it is impossible to tell from the information provided what the underlying problem was, I am willing to speculate with a high degree of certainty that all three recalls are linked back to Listeria monocytogenese contamination of the manufacturing or processing environment.

The food industry has to pay attention to this issue for several very important reasons:

• The regulators are increasing testing, and when a positive food sample is found it will result in a recall of product if that product is in commerce.

• Increased testing at the manufacturing, processing and retail level will be targeted to looking for contamination in critical zones of equipment and surfaces that may result in subsequent contamination of food. When these positives are found the result will either be a recall of product and more focused testing by the regulators, or, even in the absence of a positive food result, if the regulators feel there is a future likelihood of food becoming contaminated they will increase contact surface and finished product testing.

• When regulators find Listeria monocytogenese the bacterial isolates have their genetic fingerprint mapped and the information entered into the national data base. This then raises the possibility of matching a strain found in a food or facility with a strain that has caused human illness.

• Illness due to Listeria monocytogenese is typically linked to those with compromised immune systems and pregnant women. When this bacteria does cause illness in such individuals it is life threatening, with over 80% of individuals requiring hospitalization and a 20% death rate.

These recent recalls serve as a reminder that the regulators are looking much more for this important and deadly microbe. They are finding it, and they are taking action – and when they do find it in a finished product this could be just the beginning of the nightmare if your food is then linked with an outbreak of listeriosis that can carry a 20% mortality rate. Understanding how to control environmental contamination at the manufacturing, processing and retail level is critical, and if you don’t pay attention to that element of food safety you are running a significant risk that is becoming greater by the day as regulators are looking to find problems more than ever before.