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Help we Found a Pathogen!

28 Mar 2019

Help we Found a Pathogen!

We have designed our pathogen programme, conducted a risk review to determine the swabbing points, found an accredited laboratory and kicked-off the monitoring. Peace of mind; until the phone call on a Friday afternoon, telling us that one of our environmental swabs has come back positive (it’s always a Friday afternoon!).

The most common reaction I have seen is panic. A mad last-minute crisis meeting and some poor souls spending some very long days in the factory, cleaning and swabbing. I vividly remember my first Listeria hunt about 20 years ago, which was, you guessed it, during the weekend.

It doesn’t have to be this way!

A good environmental pathogen management programme should include a documented pre-determined response plan. Remember the reason we decided to hunt for that pathogen? It is to find that pathogen in the environment, well before it can sneak its way into our product. We shouldn’t be surprised or upset if we get a positive result, instead we should congratulate ourselves: Yippee, our programme is working!

Our response to a positive pathogen result will depend on the sample point. If we go back to our sausage factory example (previous article), the response to a positive result close to our product in the “post-kill” zone should be very different to a positive result in the pre-kill environment.

When it comes to preparing our response plans, there’s another human factor to consider: risk appetite.

I’m not sure if you have ever talked to a financial advisor? One of the first things they do, before they mention investment options, is to gauge your risk appetite to see if you are risk averse or whether you are prepared to take the occasional loss on your journey towards financial freedom.

When it comes to our pathogen response, this is no different. I have sat in crisis meetings where the risk appetites of the various managers caused some real friction. It is important that our first step is to determine the risk, acceptable to the team, so we all agree and sign-off on the pre-determined response.

I’m a food safety professional and risk aware when it comes to pathogens, so if we find a pathogen on the floor in the pre-kill zone, I may do an investigation, but consider the risk to the product to be low. However, a positive result in the post-kill area is more serious and in addition to a full traceback investigation, extra product samples should be taken.

For the investigation, a worst-case random sampling technique is now appropriate, because we know the pathogen is in the environment and we want to find the source. Unfortunately, experience shows that we are unlikely to find the pathogen again (only for it to pop up a few months later!). I think the main reason for this lack of success, is a response that is poorly co-ordinated and too fast.

Response speed is very relevant when it comes to the latest “instant” or “very rapid” testing technology for pathogens. Whilst I can see the benefits of instant pathogen results for FMCG manufacture, an environmental pathogen programme should never be used as a line clearance tool, like ATP.

Pathogens should by definition “not be” in your factory and a positive result should always lead to a full investigation. I also prefer to use the same test method for all our pathogen testing (environmental as well as final product) to minimise any post-positive test method debates.

One of the biggest advantages of an environmental pathogen management programme is: we have time!

A positive environmental pathogen result is a time to reflect (what’s gone wrong!?). We need time to maximise our chances finding the source, so we can improve our controls and systems. As I once said to the CEO of a large multinational food company: “I’m not concerned if we find a pathogen in one of your factories, I get concerned if the response to that find is lacking.”

So, here are some response plan tips:

• Bring in some fresh eyes (the hunt is on!).
• Grab your (pre-prepared) response checklist.
• Conduct an environmental housekeeping inspection first (identify the “food – moisture – shelter” spots).
• Review factory manufacturing records for unusual events/changes.
• Observe factory traffic movements for breaches.
• Include vector swabbing (has it spread? Where has it come from?).
• Do the traceback swabbing before the deep clean.
• Consider swabbing for hygiene indicators (EB, Coliform).
• Conduct swabbing over several days.


And the list goes on!

I hope you have enjoyed this mini-series and I have shown that an environmental pathogen programme is more than a “swab here and there”.

We have explored why we should have an environmental pathogen programme, what pathogens to look for, how to look for them and what to do if we find them. I have also shared some personal lessons and experiences with you, because pathogen testing can be very costly to your food business – when you get it wrong.

Finally, if it all feels a bit overwhelming, please connect. I’m more than happy to support your journey towards a robust pathogen programme, so you can have a good night’s sleep!


About The Author

With over 30 years experience in the global food industry, Jack has led the international food safety assurance team at Fonterra and is currently working as an independent consultant. Jack has managed consultancy projects in the USA, Europe and China and led the design of Fonterra’s Environmental Pathogen Monitoring Programme. If you would like to get in contact with Jack, you can do so by emailing him at jack.vds@xtra.co.nz

Jack van der Sanden

Food Safety Consultant

28 Mar 2019

Contact Jack van der Sanden


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