Emerging Issues Carry Risk

Features - Pathogen Detection and Prevention

Detecting and preventing emerging — and existing — pathogens.

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April 3, 2020

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The spread of pathogens by contaminated food continues to be a significant public health burden, with CDC estimating that every year four pathogens — Salmonella, E. coli O157:H7, Listeria monocytogenes, and Campylobacter — cause 1.9 million foodborne illnesses in the United States alone. Additionally, according to the World Health Organization (WHO), 600 million cases of foodborne disease and 420,000 deaths occur worldwide every year.

Many of these, including existing and emerging/re-emerging pathogens and diseases, are increasingly zoonotic, passing from animals to humans, said The Acheson Group Vice President of Public Health Rolando González. Not only are known foodborne pathogens re-emerging as more virulent organisms, including bacteria that have developed resistance to one or more antibiotics, but emerging organisms not previously associated with food are now becoming the source of outbreaks, such as Hepatitis E virus (HEV). Additionally, he said, “Supply chain risk is becoming more relevant, as demonstrated by Cyclospora incidents in recent years.” Because of this, “you need to understand the microbial profile of the raw materials that you source, and the potential biological hazards these might bear.”

Other emerging pathogenic issues related to food include changes in human population demographics, lifestyle, and global travel; intensified agricultural practices; the increased complexity of the food supply to global scale; the inherent ability of microorganisms to respond to environmental stressors; and even climate change factors, González said. “All result in increased pressures to food systems and have contributed to inadvertent development of more virulent pathogens and the introduction of foodborne pathogens into new geographic areas.”

With the persistence of pathogenic environmental contamination in food processing environments, how can a food facility best assess its pathogenic risk? A first step is that of “getting intimate with their supply chain and conducting a thorough supplier and ingredient risk assessment,” González said. Within the facility, it is important to evaluate and understand the sanitary conditions of your manufacturing and overall food-handling environment. This can be done through hygiene- and environmental-monitoring programs, and assessing the risk of cross-contamination from the environment’s hygienic conditions that may support pathogen harborage, as well as the nature of the product, employee practices, and environmental controls such as sanitation, he said.

To then pull it all together, “You need to understand the capabilities, limitations, and failure modes of your pathogen inactivation process controls.”

DETECTION. “Detecting the presence of new and existing pathogens in food and environmental samples is greatly aided by recent advances in molecular technologies and pathogen detection methods,” González said. An example he gave was that of Next Generation Sequencing (NGS) methods, such as whole genome sequencing (WGS – See Whole Genome Sequencing, above). WGS, he said, “allows identification of pathogens isolated from food or environmental samples, therefore supporting verification of the effectiveness of process and environmental controls, and inferring potential sources of microbial contamination.”

WGS also allows for comparison against genomic information available in an open-access reference database and can be used to differentiate between transient and resident pathogenic strains of bacteria. It is not being used in food facilities in the U.S., although other countries, such as Chile, have been using WGS at plant level for several years, González said. “Drawbacks of WGS include being expensive, requiring extended time to results, and calling for a pure culture isolate. There are also concerns among food companies with regulatory implications of sharing WGS data corresponding to environmental isolates collected at their facilities.”

But, he said, not all NGS methods are designed equally. For example, targeted NGS approaches do not require a pure isolate and offer a promising alternative to WGS. In the context of routine pathogen testing in food safety, he said, they offer diminished time to result, prices resembling PCR analyses, and high sensitivity.

In addition to environmental monitoring and controls, “the best defense against the spread of pathogens is through your frontline workers,” said Intertek Alchemy Senior Industry Analyst Holly Mockus. Every touchpoint in the food plant and supply chain is a potential breeding ground for bacteria, and that bacteria easily spreads, leading to global outbreaks, illness, or even death.

“While constant, consistent testing to detect them is an effective part of the arsenal to protect consumers, it’s not enough,” Mockus said. “No one knows the plant and processes better than your frontline workers. They are the ones whose behaviors and actions can detect pathogens and/or prevent the proliferation of them, since they are the ones interacting with all of the high touch points on the production floor.”

To utilize this vast network of worker knowledge, Mockus advises four key actions:

1. Teach. If you teach your employees what to be aware of and how to report it, your program will go from reactive to proactive overnight. For instance:

  • Listeria likes wet environmental conditions. Want to know where water pools during operations or where there are weeping curbs or equipment? Want to know what equipment is emitting a foul odor? Your employees know.
  • Sensitive ingredients may need refrigeration and can’t be left on the line for long periods of time. Do your employees understand this? What suggestions do they have for monitoring these ingredients?
  • Allergen spills can be potential sources of cross contamination. Does your team know the proper way to clean up an allergen spill? 
  • Backed-up drains are a fertile environment for pathogens that can be transported throughout your facility by foot traffic and rolling stock. Do your employees know that walking through the standing mire from a backed-up drain can track pathogens throughout the facility? Do they know what to look for and how to report this? Do they know that equipment used on drains cannot be used in other applications in the facility?
2. Ask. Your employees know where the gaps and problems are and will tell you if you give them an opening. So ask them — but be non-confrontational in your approach; don’t blame or finger point. Approaching it as a collaborative team experience, one that you’re just as much a part of as they are, will go a long way to getting buy-in from your team.

3. Recognize and Reward. Everyone likes to feel as though they are part of the team, and recognition is an easy way to create that team atmosphere. Keep in mind that rewards don’t have to require a large budget. A free drink in the cafeteria, his or her name in a newsletter or on the bulletin board, a thank you note recognizing the behavior and the outcome — all are easy ways to inexpensively prop up someone.

4. Empower and Engage. When your workers know what to do — and do it even when no one is looking — you’ve achieved the ultimate goal in safety. But it doesn’t stop there. Other ways to recognize that your training is getting through to your frontline workers is when they are empowered to stop the line or a process, ask questions, view their surroundings critically, and point out deficiencies.

Ultimately, you want your employees to feel so empowered by their knowledge that they are proud of what they do and how they do it.

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Supervisors have ample opportunity to forge relationships that foster engaged employees, as they are the ones who interact directly with them and spend most of the day on the production floor. Ways for them to do so include freely sharing information whenever possible; soliciting employees for ideas, suggestions, and feedback; and following up and following through.

PREVENTION. “To the extent that companies are committed to proactively mitigating the pathogenic risk, prevention is possible by periodically monitoring the effectiveness of the environmental controls implemented with currently available testing methodologies, trending and analyzing data obtained from those, and acting upon what it reveals,” González said.

Both existing and novel detection technologies can allow companies to make informed and proactive decisions to address risk factors, such as microbial environmental niches as sources of pathogens, and the potential for food contamination. “A good old visual inspection, coupled with some sort of rapid method (e.g., ATP) and microbiology analyses (pathogens and/or indicators), still provides most companies with a good assessment of the hygienic conditions of their food handling environment,” he said. This, then, allows for early adjustments in environmental control programs to prevent pathogen contamination.

“Implement robust hygiene monitoring and pathogen environmental monitoring programs, and consider the use of indicator microorganisms for hygiene monitoring,” he said. “This can provide early information about the sanitary conditions of the environment and enable the company to proactively address areas of concern before it’s too late.”

Documentation accuracy and thoroughness is also key in managing a robust pathogen detection and prevention program, González said. “Analyzing data and applying proper corrective and preventive actions is important from a regulatory and third-party audit standpoint, as well as for continuous improvement, he said, adding that regulatory requirements and third-party audit criteria (e.g., GFSI) dictate the need to maintain proper documentation of pathogen detection as well as preventive management efforts.

And that same documentation can provide the data that enables you to track, trend, and improve over time. “Establish a baseline, and compare results against it over time,” he said. “Trend and analyze; assess for trouble; identify the root cause of positive results; and address it.”

The author is Editor of QA magazine. She can be reached at llupo@gie.net.