Tag Archive for: listeria

Will My Facility Be Inspected? FDA Helps Small Businesses Determine Their Size

FDA published the draft guidance Determining the Number of Employees for Purposes of the “Small Business” Definition of Parts 117 and 507: Guidance for Industry on March 19, 2018. The comment period is through May 20, 2018. The purpose of the guidance is to raise awareness of exemptions for Part 117, the human food rule, and Part 507, the animal food rule. There is also a later compliance date for small businesses under the animal food rule of September 17, 2018, than originally set. I am addressing human food within this blog.

Why did FDA publish this draft guidance?
I’m having a difficult time understanding the publication of this Food Safety Modernization Act (FSMA) draft guidance at this time. It is helpful in defining subsidiary, affiliate, facility and full-time equivalent (FTE) employee. There are clear examples to showcase types of facilities and calculations of FTEs. The purpose of calculating FTEs is to determine if a facility is defined as a small business of less than 500 FTE employees. This is a concern when multiple facilities are related and if there are part-time or seasonal employees. This is a question I have tried my best to address in PCQI workshops for my participants. It’s nice to have the draft guidance. The reason I am having a difficult time is that it is a moot point for industry now. All small businesses came under enforcement in September 2017 for human food. Small businesses must meet the same requirements their larger competitors met in September 2016.

    I believe the reason for the publication of the draft guidance
    is not as much for industry as it is for the FDA.

Will my facility be inspected?*
FDA prioritizes their inspections, so FDA must know if a facility is a small business or larger. In fiscal year 2016-2017 when businesses with more than 500 employees came under enforcement, FDA’s goal was to complete 300 FSMA inspections. Facilities with more than 500 employees were under inspection first, because of the potential public health impact to a larger number of consumers. A total of 165 domestic and foreign FSMA inspections were completed. All other inspections-the majority-were Good Manufacturing Practices (GMP) inspections. That trend will continue with most inspections being GMP inspections. The FDA continues to train its inspectors on FSMA, and FDA inspectors are primarily in a FSMA educator mode with industry. In fiscal year 2017-2018 the goal is higher at 500 FSMA inspections; the pace is faster.

In addition to the number of FTEs, there are other factors used by FDA to prioritize inspections.

    • Domestic and foreign facilities goals are 400 and 100 inspections, respectively.
    • Facilities with a current or previous Class I recall or warning letter
    • Facilities in the same market as a facility with a Class I recall
    • Facilities making a high-risk ingredient or product

      1. Ready-to-eat foods
      2. Foods identified in FDA’s Listeria risk assessment
      3. Foods otherwise with a history of risk

While it is not possible to know if your facility will be inspected until the FDA inspectors are at your door, you can determine the likelihood by using the same tools FDA has to prioritize inspections.

*The author participated in a Food Safety Preventive Controls Alliance quarterly webinar for Lead Instructors on February 8, 2018, in which FDA inspection data was shared.

The ConnectFood website has free resources, and the folks at ConnectFood are here to help! Contact us.

About the Author
Kathy Knutson, Ph.D.
Kathy Knutson Food Safety Consulting
Dr. Kathy Knutson works nationwide with food manufacturers on recall investigations, problem-solving, training, and Food and Drug Administration (FDA) compliance. After being trained in 2016 as a Lead Instructor with the FDA-recognized curriculum for Preventive Controls Qualified Individuals, she delivered over 20 workshops to industry. With over 35 years in microbiology and 15 years of full-time teaching, Dr. Knutson is passionate about training and is an effective communicator at all levels in an organization. She has taught and consulted with companies on laboratory methods, interpretation of lab results, quality assurance, sanitation, environmental monitoring, Standard Operating Procedures (SOPs), Good Manufacturing Practices (GMPs), Hazard Analysis and Critical Control Points (HACCP) and the FDA’s Food Safety Modernization Act (FSMA). As a life-long learner, Dr. Knutson is trained in prevention of intentional adulteration, a topic on the horizon for the food industry. Dr. Knutson is a contributing author at CannabisIndustryJournal.com. Dr. Knutson writes a food safety blog and contributes expert services to manufacturers through connectfood.com, an online site for writing HACCP and food safety plans. When Dr. Knutson is not traveling, she works from home in Green Bay, Wisconsin, where she lives with her husband, two sons, and an adorable Bernedoodle. Learn more about her at https://www.linkedin.com/in/kathyknutsonphd

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FDA Listeria Draft Guidance for Ready-to-Eat Foods: Part 2

I first learned that Listeria monocytogenes is a foodborne pathogen in 1985 during the Jalisco cheese outbreak in Los Angeles and Orange Counties in California. There were 29 deaths from 86 documented cases. The veterinary world was very familiar with Listeria in cattle, long before food microbiologists. Industry and the federal Food and Drug Administration (FDA) took this emerging pathogen seriously. Since 1985, there has been active research and investigations at universities and food companies. We know that Listeria is ubiquitous, and current lab methods improve our chances of finding Listeria.

FDA Listeria Draft Guidance for Ready-to-Eat Foods: Part 1, published previously at connectfood.com, discussed Listeria testing on food contact surfaces (FCS) and non-food contact surfaces (NFCS) and from finished product. We encourage you to study FDA’s draft guidance, Control of Listeria monocytogenes in Ready-To-Eat Foods: Guidance for Industry. Here, I present three concepts needed to understand the information in the guidance.

A positive Listeria test from a FCS assumes the presence of Listeria in your product.

The guidance for ready-to-eat food recommends FCS be sampled after three hours of production and five FCS samples be collected per week per line. First consider these sample sites. The FCS sites should be after the final kill step. It does no good to sample FCS sites before the final kill step. If the test is positive, the assumption is that the final kill step killed the pathogen. The FCS sites are before the final product is sealed in packaging. Think about the distance where your product travels after the final kill step to where the package is sealed. In that distance, think about where the product is open to the environment. Listeria is an environmental pathogen. What I mean is if the product is in tubing, the product is not exposed to the environment, and these would not be FCS sites for Listeria. I am thinking about an ice cream plant. The mix travels through tubing until carton filling. The distance the product travels from the end of the tube to the carton is small, and the distance the open carton travels until sealed is small. Compare that to a large bakery. After leaving the oven on conveyor belts, the baked goods travel open to the environment for cooling and the addition of toppings. I have seen distance as long as 50 yards with the transfer onto multiple conveyor belts.

Once you have your FCS sites identified and if a FCS test is positive, it is assumed the product is positive, even without direct sampling and testing of the product. This makes sense. If a FCS is positive, the product touched the FCS. At that point it’s a chicken-and-the-egg discussion of whether the product contaminated the surface or the surface contaminated the product. It doesn’t matter until you do your root cause analysis. What you do know is that you have contaminated product.

A positive Listeria test from an environmental sample has an isolate identified as Listeria innocua or another Listeria species; consider Listeria monocytogenes as present.

Listeria monocytogenes is one of 17 species of Listeria. Only the species Listeria monocytogenes is considered a foodborne pathogen. When your contract lab tests for Listeria genus or spp., a positive test does not tell you the species. Further testing can identify the species, if needed. It is very common for the lab to report negative for Listeria monocytogenes and report the presence of Listeria innocua instead. In no way can you rest easy with a positive Listeria test and negative Listeria monocytogenes test. When the lab reports a positive Listeria test, consider Listeria monocytogenes present.

Consider the sampling site and technique. Let’s use the example of a drain swabbed with a sterile sponge. Assume Listeria monocytogenes is there. Perhaps the sponge did not swab the location of the pathogen. Perhaps the sponge did not get through the layers of goo where the pathogen is harbored. There are many reasons for missing the pathogen in the procedure for swabbing. If the test is positive for a different Listeria species, the conditions at that site are conducive for the presence of Listeria monocytogenes. Corrective action must be done in the same way as if the test were positive for Listeria monocytogenes.

Consider the variety of microflora at the site. The site was not sterile and does contain diverse types of bacteria at different numbers and proportions to each other. Listeria monocytogenes is the wimpy kid on the playground. Listeria innocua outcompetes Listeria monocytogenes not just 10-to-1, but as much as 20:1 or 50:1! The mere chance of finding Listeria innocua instead of Listeria monocytogenes is simply greater. Listeria monocytogenes may have been present in the sample, in the testing, and simply not detected.

An environmental sample tests positive for Listeria genus or Listeria species (spp.); react as if the sample were positive for Listeria monocytogenes.

You will direct the lab in what method to use and at what point to stop the testing. Work with the contract lab in making this determination. After a positive test for Listeria genus or spp., you have the option to continue testing to identify the isolate of Listeria. This costs more money and time. Will you do something different with that information? No! It is not necessary to confirm the presence of Listeria monocytogenes from a positive Listeria genus or spp. test, when your corrective action is the same. Think this through before testing. Know the action the plant will take when a Listeria genus or spp. test is positive. Expect to get positives from zones 3 and 4. FDA inspectors should not have a problem with seeing occasional positive tests. Since Listeria is ubiquitous, you are expected to find it. The important part is what you do as corrective action. Follow-up testing should be negative to prove Listeria is eliminated from the site and the area adjacent to the site.

As you work through the FDA Listeria guidance, the ConnectFood website has free resources, and the folks at ConnectFood are here to help! Contact us.

About the Author
Kathy Knutson, Ph.D.
Kathy Knutson Food Safety Consulting
Dr. Kathy Knutson works nationwide with food manufacturers on recall investigations, problem-solving, training, and Food and Drug Administration (FDA) compliance. After being trained in 2016 as a Lead Instructor with the FDA-recognized curriculum for Preventive Controls Qualified Individuals, she delivered over 20 workshops to industry. With over 35 years in microbiology and 15 years of full-time teaching, Dr. Knutson is passionate about training and is an effective communicator at all levels in an organization. She has taught and consulted with companies on laboratory methods, interpretation of lab results, quality assurance, sanitation, environmental monitoring, Standard Operating Procedures (SOPs), Good Manufacturing Practices (GMPs), Hazard Analysis and Critical Control Points (HACCP) and the FDA’s Food Safety Modernization Act (FSMA). As a life-long learner, Dr. Knutson is trained in prevention of intentional adulteration, a topic on the horizon for the food industry. Dr. Knutson is a contributing author at CannabisIndustryJournal.com. Dr. Knutson writes a food safety blog and contributes expert services to manufacturers through connectfood.com, an online site for writing HACCP and food safety plans. When Dr. Knutson is not traveling, she works from home in Green Bay, Wisconsin, where she lives with her husband, two sons, and an adorable Bernedoodle. Learn more about her at https://www.linkedin.com/in/kathyknutsonphd

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FDA Listeria Draft Guidance for Ready-to-Eat Foods: Part 1

FDA Listeria Draft Guidance for Ready-to-Eat Foods: Part 1 is an outline of essential information on the Listeria draft guidance, answering who, what, when, where, why and how questions. The guidance is written for companies manufacturing ready-to-eat (RTE) food and ingredients. As a guidance document the language is different from a rule where companies are required to comply. In general, an FDA guidance document does not require compliance, is written to help industry interpret rules, and explains FDA’s current thinking on a topic. The FDA Listeria Draft Guidance is different. In this author’s opinion, the guidance carries the full weight of a rule and will be enforced as such by FDA. If your company manufactures a RTE food, your President or company owner must be fully informed on the contents of the guidance. This paragraph answers why.

Who must test for Listeria?
All food companies making RTE foods under the jurisdiction of the federal Food and Drug Administration (FDA).

What must be tested for Listeria?
The company will identify food contact surfaces (FCS) and non-food contact surfaces (NFCS) as appropriate to the design of individual facilities. Finished product testing is discussed in the guidance and is recommended.

    We recommend that you establish and implement a written procedure for the periodic collection of samples of your RTE food product, and for testing those samples for the presence of L. monocytogenes. See page 52.

What sterile supplies are needed?
The best method to sample a surface uses a premoistened, sterile sponge on a stick. My personal favorite comes from World Bioproducts. In addition to sponges, companies can use any sterile tool including Q-tip type swabs, tongue depressors to collect solids, scoops, dippers, pipets, bottles or bags. If you are concerned about contamination during sampling, have sterile gloves available for your technicians and intensify training. Finished product may be shipped in final packaging, or, if the finished product is large, a trained technician can obtain a portion aseptically to ship.

What lab method for Listeria is used?
When samples are sent to your contract lab, you specify for the testing of Listeria genus or Listeria monocytogenes. You can specify a one- or two-step enrichment. There are pros and cons for every method and its application, but you are expected to use a standard method which has been validated when testing for Listeria. Indicator tests which do not directly test for Listeria are useful for zone 1 and 2 samples; my favorite is an indicator test called HQA.

When are FCS sampled?
Warning! Warning! You are not going to like the answer. FDA wants food companies to sample FCS after three hours into production. The reasoning here is that microbial niches will have shook free and the conditions are representative of normal operations. Be very careful if following this FDA recommendation.

When are NFCS sampled?
NFCS can be sampled at any time provided food is not affected in the process of sampling and a positive Listeria test would not be associated with the product. When NFCS are tested as part of pre-op, this is a verification activity for a sanitation program.

Where are samples taken?
FCS and NFCS samples must be taken from every production line and from any area in the facility beyond production lines.

How many samples are taken?
A minimum of five samples from FCS (Zone 1) must be taken from every line every week. A minimum of five samples from NFCS must be taken. Imagine you have four lines in each room. You will take a minimum of five FCS samples from every line, for a total of 20 samples. Know that FDA is very conservative on their definition of FCS. For example, a control panel can be a FCS, if the technician who touches the panel in turn touches the production line or product. The same is true of overhead structures like pipes where condensate or powder could fall on to the product. How you interpret the minimum of five NFCS samples is up to you and dependent on the variables in that room. In general, FDA wants to see more samples from Zones 1 and 2 than from Zones 3 and 4.

What is the frequency of testing for Listeria?
Designing the sampling plan for Listeria testing is an art and a science and determines the cost to the company. Here are examples provided in the FDA Listeria Draft Guidance. See pp. 37-38. Pay attention to the wording on frequency:

    An example of how to specify the frequency of sample collection in a written environmental monitoring plan for FCSs in an establishment producing an RTE food that supports growth of L. monocytogenes is as follows:
    • Collect environmental samples from specific FCSs on the production lines at least once every week when the plant is in operation; and
    • Test each FCS in the plant at least once each month.

    An example of how to specify the frequency of sample collection in a written environmental monitoring plan for non-FCSs in an establishment producing an RTE food that supports growth of L. monocytogenes is as follows:
    • Collect environmental samples from representative sets of non-FCSs at least once weekly for zone 2 sites, every two weeks for zone 3 sites, and monthly for zone 4 sites when the plant is in operation; and
    • Test all non-FCS sites identified in the monitoring plan at least once each quarter.

Table 4 in the guidance, pp. 34-35, is the only published FDA guidance on zone designation of which this author is aware. Please share FDA publications on zone designation with me. I would love to talk through the design of your Listeria sampling plan with you. You can reach me by signing up for Expert Services on connectfood.com.

Of course you still have questions! The ConnectFood website has free resources, and the folks at ConnectFood are here to help! Contact us.

About the Author
Kathy Knutson, Ph.D.
Kathy Knutson Food Safety Consulting
Dr. Kathy Knutson works nationwide with food manufacturers on recall investigations, problem-solving, training, and Food and Drug Administration (FDA) compliance. After being trained in 2016 as a Lead Instructor with the FDA-recognized curriculum for Preventive Controls Qualified Individuals, she delivered over 20 workshops to industry. With over 35 years in microbiology and 15 years of full-time teaching, Dr. Knutson is passionate about training and is an effective communicator at all levels in an organization. She has taught and consulted with companies on laboratory methods, interpretation of lab results, quality assurance, sanitation, environmental monitoring, Standard Operating Procedures (SOPs), Good Manufacturing Practices (GMPs), Hazard Analysis and Critical Control Points (HACCP) and the FDA’s Food Safety Modernization Act (FSMA). As a life-long learner, Dr. Knutson is trained in prevention of intentional adulteration, a topic on the horizon for the food industry. Dr. Knutson is a contributing author at CannabisIndustryJournal.com. Dr. Knutson writes a food safety blog and contributes expert services to manufacturers through connectfood.com, an online site for writing HACCP and food safety plans. When Dr. Knutson is not traveling, she works from home in Green Bay, Wisconsin, where she lives with her husband, two sons, and an adorable Bernedoodle. Learn more about her at https://www.linkedin.com/in/kathyknutsonphd

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Sanitation Basics in the Food Industry

Today I am writing an introduction to cleaning and sanitizing procedures. Twenty years ago, I believed most spoilage issues and contamination of food were due to poor cleaning and sanitizing. The food manufacturing environment is much more complex now with the concern of allergen cross-contact and the hunt for Listeria in growth niches. Here is a foundation on which to build your cleaning and sanitizing program.

What is soil?

Soil is very simply matter out of place. A lubricant on a gear is in the right place. If you get the lubricant on a food contact surface, like a conveyor belt, the lubricant has soiled the surface. When production shuts down, every particle of food on the equipment and floor is soil, and it is the job of the sanitation crew to remove the food, including any surface film from fat, protein, carbohydrate or mineral build-up. When soil is removed, the process is cleaning.

It is not possible or desirable to remove everything on a surface, down to the smallest bacterium or virus. If the surface is free of every living cell, the surface would be sterile. This is not a realistic goal in the food industry. At the microscopic level, cells adhere to the surface of the equipment and remain after cleaning. THIS IS NORMAL. The purpose of sanitizing is to kill cells which remain after cleaning. In this way, you see that it is not possible to clean and sanitize at the same time. Neither the work of cleaning nor the work of sanitizing would be efficient. It is a waste of resources to clean and sanitize in one step.

The sanitation crew members are your most valuable employees.

The work of sanitation starts your day. Production follows sanitation. Production does not start until sanitation has done their job correctly and completely. Some companies run sanitation during business hours, to emphasize that the work of sanitation parallels the work of upper management. Sanitation crews have a lot of turnover and require extensive training and monitoring. The crew must be supplied with the resources they need to do the job right. Sanitation crew members should earn some of the highest wages among a company’s workers.

There are four crucial factors for successful cleaning and sanitizing.

For successful cleaning and sanitizing, the factors are time, temperature, concentration, and energy. In general, the more, the better. However, you will use EPA-registered cleaning or sanitizing chemicals and follow the directions from the chemical supply company. It makes sense that cleaning at a higher temperature is better, but running the equipment at a higher temperature may cause damage, and workers cannot be exposed to excessive temperatures. With concentration, more is not better after a certain point. Using 5% bleach is not recommended due to its corrosive property. Energy can be supplied by manual scrubbing or by turbulence within equipment.

What are clean-in-place (CIP) and clean-out-of-place (COP) procedures?

CIP systems for cleaning are installed when a continuous loop of equipment, pumps, and pipes can be developed. CIP systems are designed with your chemical supply company to run at much higher temperatures, concentrations, and turbulence than can be achieved in a tank. COP cleaning can be done in an open tank with recirculating solution in which the disassembled parts sit, or COP cleaning can be done with manual scrubbing of parts in a bucket or tank.

With the concepts described here, I hope you can build a successful cleaning and sanitizing program. Other blog posts here at ConnectFood elaborate on the topic of cleaning and sanitizing.

The search for forms and checklists can be overwhelming, and the ConnectFood website has free resources. The folks at ConnectFood are here to help! Contact us.

Dr. Kathy Knutson has food safety expertise in microbiology, hazard analysis, and risk assessment. As a recovering academic, she resides in Green Bay home-of-the-Packers, Wisconsin with her brilliant husband and two handsome sons. Learn more about her consulting services at https://www.linkedin.com/in/kathyknutsonphd.

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What is FDA Going to Look for When They Swab?

Swab samples taken by the Food and Drug Administration (FDA) are intended to find pathogens, if present: Salmonella, Listeria monocytogenes, or pathogenic Escherichia coli. These are three pathogens to put fear in the strongest food safety professional. I recently left a food facility where we discussed all three. If Salmonella is the old, and L. monocytogenes is the current, then pathogenic E. coli is the future.

Every Salmonella is pathogenic. Some Salmonella are associated with their source, like turtles and chickens. The majority of foodborne illness is caused by just ten out of thousands of serovars of Salmonella. When we come across a Salmonella that is not among the top ten, we take note. That was the case with the Valley Milk recall. Salmonella meleagridis was identified. This one is rare. What does that mean? It means it was unique to the product and environment. Since it is unique, it may be able to be traced to a source. All Salmonella patient isolates are tested by whole genome sequencing (WGS) and are in the PulseNet database. If there are any patient isolates of Salmonella meleagridis, the Centers for Disease Control and Prevention (CDC) will investigate the link between the patient and consumption of food with the contaminated milk product.

What is an isolate? In a sample of patient fecal matter, finished product, raw ingredient, or environmental swab there is a variety of microorganisms, mostly harmless. When the lab pulls out the pathogen from among millions of other cells, the pathogen is grown as a pure culture. This is the isolate. This is also why microbiological testing takes time. Our lab tests are designed to find one pathogenic cell among millions of harmless cells.

Salmonella is big deal. An estimated one million cases of salmonellosis occur every year in the United States. Where will FDA test your facility for Salmonella? FDA will sample dry ingredient storage, dry blending, and “dry” operations. Roasting and grinding of nuts are dry operations. Nut butters and oil-based products are made in a dry area, i.e. where there is no use of water. The facility I just left was a wet operation, except for one product where they had a dry seasoning. When FDA swabs, they could test that one area for Salmonella. For the most part, FDA is not currently focused on Salmonella. The exception to that is manufacturers of products in an industry where there have been recalls, like peanut butter.

Keep your ears open for recalls by your competitor. You can sign up for recall alerts.

Listeria is the current favorite of the FDA and CDC. For example, there was an FDA initiative to visit raw milk cheese plants for swabbing. Other foods are not immune. FDA is going to facilities and conducting intensive swabbing. When the FDA arrives with a handful of inspectors, over 100 environmental sites will be swabbed from zones 1, 2, 3 and 4 per day. Product samples will be taken. My advice is to hold all product made on those days until Listeria tests are negative. Negative results should be reported within days. If Listeria tests are presumptive, consider discarding the product. However, be prepared to wait weeks for FDA to communicate results. What do you do if you can’t hold your product? Discard it. Limit the runs on the days the FDA is swabbing. Document the disposition of the product, in case the results come back positive. Companies have decided to simply discard perishable finished product made during these inspections, rather than wait for results.

Why wait for the FDA to show up for swabbing? My advice is to conduct your own intensive swabbing exercise. Know the areas of your facility that are hot for Listeria. Do you have to test product? No. Do you have to test zone 1 for Listeria? No. For zone 1 food contact surfaces, I recommend Enterobacteriaceae counts. You could do coliform or E. coli testing instead of Enterobacteriaceae. Do you have to test for Listeria monocytogenes? No. You can test for Listeria genus. Of the 17 species of Listeria, only L. monocytogenes is pathogenic. Getting a positive Listeria genus test means the environment is conducive for L. monocytogenes.

There is a difference between Listeria genus and Listeria monocytogenes testing. First, you will get the Listeria genus results quicker. Second and if you stop testing at Listeria genus, you will not have direct documentation of the presence of L. monocytogenes, the pathogen. The key is in your corrective action. Your corrective action might be the same whether the test is a presumptive Listeria genus test or a positive L. monocytogenes test. In other words, treat the seriousness of a presumptive Listeria genus the same as a positive L. monocytogenes.

The FDA published the draft Listeria guidance in January 2017. The guidance is currently in its comment period. All draft guidance represents the FDA’s current thinking on a topic. While not mandated, FDA expects industry to conduct environmental monitoring for Listeria when ready-to-eat (RTE) foods are manufactured. There is even greater FDA scrutiny for RTE foods which can support the growth of Listeria. We are anticipating another FDA guidance document to further define RTE foods. In the meantime, refer to the Preventive Controls Hazard Guide; it is 185 pages. There are categories of food, their hazards, and examples of food in the category. This is FDA’s current thinking on hazards in food. If the food is categorized as RTE, the facility should have a Listeria environmental monitoring program.

Do you need help in designing your environmental monitoring program? I would love to help!

Every isolate of L. monocytogenes from a patient has been sequenced by WGS and is in the PulseNet database. This fact keeps food safety professionals up at night. The FDA can pull a food from the grocery shelf, isolate L. monocytogenes, inform the company to initiate a recall, and match the food isolate to a patient isolate. Check out my previous post, What I want all my students to know about Listeria.

Most E. coli are not pathogenic. We can test on-site at a food facility for Enterobacteriaceae, coliforms, or E. coli and not be in fear of growing billions of cells of pathogenic E. coli. For now, what you need to know is that patient isolates of pathogenic E. coli will be sequenced by WGS and be in the PulseNet database. In the same way that Salmonella or L. monocytogenes can be matched from food isolate to patient isolate, so will pathogenic E. coli be matched. The technology and laboratory expertise are there.

It is somewhat comforting to know that that while the number of recalls is increasing, the number of cases, i.e. patients, is decreasing. The food industry is making great strides in food safety. Because of greater surveillance and communication, the average number of cases (patients) per outbreak has decreased. The number of multi-state outbreaks has increased for the same reasons.

There is much to be hopeful about around food safety. Job security is one!

Dr. Kathy Knutson has food safety expertise in microbiology, hazard analysis, and risk assessment. As a recovering academic, she resides in Green Bay home-of-the-Packers, Wisconsin with her brilliant husband and two handsome sons. Learn more about her consulting services at https://www.linkedin.com/in/kathyknutsonphd.

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What I want all my students to know about Listeria

The FDA guidance on Listeria is now out in draft form. I have known about Listeria since I was in grad school at the University of Wisconsin-Madison in 1985. That is when I learned about Listeria, but farmers and vets had known much longer. I now know that many of the miscarriages in friends, aunts and grandmothers were caused by the presence of Listeria in raw milk and from exposure in the Wisconsin farm environment. When I teach the workshop on Preventive Controls for Human Food or in other work, this is what I tell my students.

Listeriosis is an infection by Listeria monocytogenes. There is a primary and potential secondary infection. We have all consumed Listeria. Most Listeria passes through us without causing an infection. When the primary infection develops, most of us experience flu-like symptoms and recover easily. You may have had listeriosis and not even known it.

Some of us cannot fight the primary infection, because the immune system is already weakened or compromised. This includes adults who are highly stressed, undergoing chemotherapy to fight cancer, with suppressed immune systems for bone marrow or organ transplant, or who have immune-suppressing conditions like HIV, auto-immune diseases, and pregnancy.

After Listeria colonizes the intestine, cells will transfer through the lining of the intestine and into the bloodstream. This is sepsis, and a healthy body may still fight off the infection. Once in the bloodstream, Listeria has access to all parts of the body. Listeria has the unique ability to cross membranes that other bacteria do not. Listeria can cross the barrier of the brain, the meninges. The infection is called meningitis and known as circling disease in cattle. Listeria can infect the eye and cause conjunctivitis. Listeria can cross the heart lining and cause endocarditis. Listeria can set up shop in the vagina, such that when an infant is born, the infant is exposed to the pathogen. Post-partum infant deaths may be caused by Listeria.

The most impressive feat of Listeria is its ability to cross the placental barrier. I am not aware of any other bacterium capable of this. Let me know, if you know of one. Depending on the age of the fetus, Listeria infection causes a miscarriage or death shortly after birth. This is heart-breaking, and most of us know a woman who has suffered a miscarriage. Not all miscarriages are due to Listeria.

When the CDC tracks a Listeria outbreak, the number of fetal deaths are counted along with the infant, child and adult deaths. The number of deaths from Listeria is staggering and can be as high as 40% in an outbreak. The average is 20% mortality rate from listeriosis. While the sheer number of Listeria cases, i.e. individuals, is nowhere near the annual one million cases of Salmonella, it is the number of deaths that makes Listeria a pathogen of concern.

If you need help understanding the FDA Listeria guidance or the requirements for your food safety plan, please contact the friendly folks at ConnectFood.

Dr. Kathy Knutson has food safety expertise in microbiology, hazard analysis, and risk assessment. As a recovering academic, she resides in Green Bay home-of-the-Packers, Wisconsin with her brilliant husband and two handsome sons. Learn more about her consulting services at https://www.linkedin.com/in/kathyknutsonphd.

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