Neogen Corporation
10/17/2024 | Press release | Distributed by Public on 10/18/2024 10:58
Partners in Food Safety: Positive Test Result
When a food safety team is alerted to a positive test result, especially a pathogen, that team's food safety program is challenged. Immediate action can mean the difference between a minor inconvenience and major problem for the organization and even a public health risk. How a company responds is critical, but the proactive work done ahead of any positive test result will dictate how well a food manufacturer is able mitigate this undesirable situation.
We recently sat down with industry Food Safety professionals Arpan Bhagat and Dr. Martin Wiedmann to discuss the impact that a positive test result has on a food manufacturing operation and provide insight on what immediate next steps should be when, "A positive test result has occurred, now what?"
Not All Positive Results Are the Same
How an organization responds to a positive test result will vary on the specifics of the test. Is this the first instance of this type of positive? Where in the manufacturing process was the test taken? Answers to these questions will dictate the next steps for food safety professionals and will set the stage for how the organization takes action to address the adverse result.
"Getting a positive in a Zone 1 is the most critical test result that you can get.", says Arpan Bhagat, a food safety professional with almost 20 years of experience. "It has the same level of criticality as a product positive result. Zone 1 and product positives are your most critical results, and they have to be escalated to the upper management the moment that information is received."
"Now when we go to Zone 2, Zone 3, Zone 4's, those positives are nearly not as critical as Zone 1 or a product positive. You don't want Zone 2, Zone 3's to be positive. You do your cleaning and sanitation; you eliminate the pathogens from those zones. But there needs to be a clear understanding of what the definition of these zones are and what those positive results mean when you receive them from the third-party lab or if you have an in-house lab where you're performing those pathogen test results."
Figure 1. Environmental monitoring sampling zones
Similarly, the impact that a positive test result can have depends on an organization's ability to address the positive and any product that may be impacted by the undesirable testing results. As a food safety plan is developed, determining when to test can be as important as determining what to test, according to Bhagat. "One of the basic things that needs to be done is anytime you are testing a product for pathogens, you have to 1st ensure that the product is under your control before you even think about testing it for a pathogen like Salmonella or Listeria. Because once you receive the result and if your product is already in the market, the ship has sailed."
Managing a Positive Test Result
Food manufacturing organizations vary wildly in their size and structure and thus will have varying experience in dealing with positive test results. For someone not familiar with food safety best practices, their first instinct may not be the best way to utilize accurate sampling procedures to identify contamination sources, according to Dr. Martin Wiedmann, professor in Food Safety at Cornell University. "So a big question comes up; 'after an environmental positive, shouldn't I clean and sanitize first and then collect more samples?' Someone new (to food safety) might be prone to just want to make sure they don't find another positive. And the easiest way to do it is to just pour sanitizer all over the place and then sample. And then you're not going to have a positive, however, this approach prevents you from getting the data needed to know where the positive came from and hence prevents you from doing a good root cause analysis. With that, the risk is high that the real root cause was not addressed and that you will get more positives in the future."
Dr. Wiedmann stresses that additional testing is needed to understand the severity of the issue and to ensure that corrective actions are as impactful and successful as possible. "The next step would be to do what we call vector swabbing. So, we've got a positive here, let's collect another sample from that same site and then collect samples around it. So, vector swabs usually refer to the idea of vectors going in a different direction, typically at least up, down, north, east, south, and west from the original positive with a focus in sampling sites that represent a likely location where the organism may survive and originate from."
A positive test result may not immediately dictate a complete production shutdown according to Dr. Wiedmann. "If you just focus on the US current regulatory environment, an environmental positive for Listeria does not mean you have to recall your food; the FDA somewhat recently changed their stance with regard to zone 1 positives for Listeria spp. IF you have a single zone 1 Listeria spp. positive, you do not have to a recall. It just means you really have to do a stringent root cause analysis, have to retest, and then if you have two or three positives in a row, at some point you need to stop production. The US FDA guidance document is very clear about what you need to do."
Figure 2. Example of Food Contact Surface testing and follow-up activities.
Dr. Wiedmann continues, "If it's a Zone 1 positive, you're really going to need to up your game and have a written record of your root cause analysis procedures and then really follow through and try to fix the root cause. Also, you will need to do more follow up testing. You may not want to just take 5 or 6 samples; you might move into the 10 to 20 samples. And again, you should have a good and detailed written procedure that should specify all these details, such as the number of vector swabs to be taken after a positive."
Inclusive Corrective Actions
Though cleaning and sanitation are essential parts of routine food safety processes, a fully developed corrective action involves much more. "Not everything is related to cleaning and sanitation," noted Arpan Bhagat. "Whenever there is a pathogen test result, regardless of the zone, you should critically think about the condition of your infrastructure, the traffic patterns. There are various other things besides cleaning and sanitation that can impact a pathogen test result."
When addressing corrective actions, it is critical to expand the conversation to include others within the organization in order to identify appropriate and well-rounded corrective actions.
"There needs to be a multidisciplinary team that works on every pathogen positive test result," details Arpan Bhagat. "And you will be more successful when you get contributions from operations and maintenance, and your cleaning and sanitation departments, because it should not (solely) be the job of QA to come up with the corrective actions. They may not have the expertise that operations and maintenance and engineering and cleaning and sanitation departments do. So, you do need this to be a multidisciplinary corrective action rather than a QA corrective action."
Mr. Bhagat stresses the importance of culture when developing and enacting effective and successful corrective actions. "We don't need to come together just in a crisis situation. We need to have a relationship where people will volunteer to help you in a crisis situation and when you know the key personnel in your maintenance department, and your cleaning and sanitation department, and when the operations (team) provides you important clues regarding how the best corrective action should be designed for a pathogen hit. Those are the most successful corrective actions."
A corrective action's impact can be limited by the amount of time that it takes for a food safety plan to be activated. The gap in time between a known positive test result and the implementation of a corrective action can mean the difference between a minor internal issue and a costly and dangerous public health concerns. Utilizing a digital food safety testing platform like Neogen Analytics can accelerate the initiation of the activities that are specified in the food safety plan as next steps once adverse testing results are known. To see how digital food safety automation can help mitigate spoilage situations, learn more about Neogen Analytics today.
While a positive test result is an undesirable outcome, the true measure of success lies in the response. Neogen supports our customer's efforts to improve detection and build the capabilities, plans, and actions to address these results to positively impact production, brand reputation, and public health.
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