The second part of the article focuses on the remining two challenge questions regarding environmental monitoring programs, namely corrective action initiation and root cause investigation.

Challenge No. 2: Is Corrective Action Initiated on a Presumptive or Confirmed Positive Result?

One of your best resources is the people at your third-party testing laboratory. Someone can clearly explain the advantages and disadvantages of different indicator or pathogen methods, not just based on cost, but also time to results, sensitivity of the method, and validation of the method for environmental samples instead of product samples. Specific methods exist for environmental samples of sponges, swabs, water, and air. All methods are not created equal.


A big warning here is to never take (or submit) a sample unless the corrective action is known. If a non-food contact surface tests positive for a pathogen, what will the first step be for corrective action? For most facilities, the answer is intensified cleaning. What does that mean? Write a Standard Operating Procedure (SOP) for the decision-making and define the next steps after a positive. With a
well-written SOP, an EMP team is not making decisions with each positive, but everyone is following the SOP.


Not all positives are created equal. When a pathogen method is ordered for an environmental sample, most methods have the steps of presumptive positive, confirmed positive, identification, and serotype. Each step in the method adds more and more time when corrective action needs to be initiated. Most facilities order serotyping for investigational testing, but not routine testing.
Identification is also common for investigational testing, but not as common for routine testing. Pre-define the corrective action based on results of routine testing. If the corrective action will be the same despite the result being a presumptive positive, confirmed positive, or identified pathogen, why wait the extra days? That is valuable time wasted that could have been used to perform intensified sanitation and a root cause investigation.


A facility may get notice of a presumptive positive, although the sample does not confirm it. A facility may get notice of a confirmed positive, and the sample does not identify as the pathogen but as a close relative instead. It can be frustrating. There should not be a sense of relief when the pathogen is not confirmed. There is an important point here. Most pathogens are not competitive. The site that
tested as even a presumptive positive means the site is conducive for a pathogen. It also means that the pathogen may have been present in small amounts and missed in the testing. The pathogen may have been outcompeted in the environment, the testing, or both. In microbiology, we say negatives mean nothing and positives mean everything, because it is very difficult to find a pathogen (i.e., get a
positive pathogen result).


So, back to the challenge question: Is corrective action initiated based on a presumptive or confirmed positive pathogen result? Take presumptive pathogen results seriously. If the corrective action is the same for either a presumptive pathogen result or a confirmed pathogen result, you do not need to wait for confirmation or identification to initiate corrective action. Testing costs may be reduced when testing stops at presumptive positives.

Challenge No. 3: Does the Root Cause Investigation Locate the Source of the Pathogen?

A big red flag is when managers say they do not have time to investigate the source of the pathogen. That happens a lot in industry: a pathogen is found, sanitation is intensified, further swabbing is negative for the pathogen, and everyone moves on. Then, the pathogen comes back later. What was, and is, the source? Ingredients, humans all the way back to the agricultural workers in the field, and transportation vehicles from the field to processors to manufacturers are all potential sources of contamination, in addition to the environment, air, and water at a facility.


Why is a successful root cause investigation important? If the source of the pathogen is not found, then the pathogen will reappear and eat up resources again and again. Facilities with recurring pathogen results may harbour the potential of a resident pathogen and the facility may be manufacturing contaminated product over a long period of time and endangering public health.


Addressing these three challenges of EMPs is resource-intensive, but the payoff is huge for customer loyalty and the protection of public health. Food safety is a management program for continuous improvement, and an EMP should not be written and shelved, but continue to evolve.


Look for answers to those questions and others with us as the industry continues to grow and evolve with the everchanging times.

Article by: By Kathy Knutson Ph.D., PCQI