Part 4 Corrective Actions Lisa Olsen Specialist Adviser

Part 4: Corrective Actions Lisa Olsen Specialist Adviser, NZ Standards

What should you get from this guide? • A clearer understanding of MAF’s expectations if there is a Listeria contamination event • Information which can be used to develop your LMP and help you prepare for a contamination event

Definitions • Contaminated product means product that testing has shown to be contaminated with L. monocytogenes. • At risk product means all batches of product that are potentially contaminated with L. monocytogenes • Contamination event is when Listeria and/or L. mono are detected on product contact surfaces and/or in product during routine monitoring, surveys or an illness investigation.

How might you receive a Listeria Notification? • Routine environmental monitoring • Routine product testing • Customer sampling • Regulatory surveys • Illness investigations

Corrective Actions • Halt processing • Isolate affected equipment and areas • Notify verifier, Food Act Officer or MAF within one working day of notification

Corrective Actions • Retrieve or recall contaminated and at risk product • Identify and hold contaminated and at risk product

Investigate Cause of Contamination • Inspect contaminated process area(s) and equipment • Carry out investigative environmental sampling to identify any environmental contamination source

Investigative environmental sampling • Commence within 1 working day of receiving notification • Explore all possible areas of contamination rather than focus on small areas • Review environmental results from other areas to identify areas that may require reassessment of controls • Testing at higher level should continue until source of contamination identified • Thoroughly clean and sanitise once sampling completed

Investigate cause of Contamination • Review supporting system and processing records • Sample raw and in-process materials • There is a good chance that more than one thing is the source of problem – it is quite likely to be a combination of things – keep an open mind

Clean and sanitise • In a high proportion of cases where Listeria contamination occurs there have been problems with the cleaning and sanitising programme • A person with the appropriate level of expertise should be involved in any review of the programme.

Intensive Microbiological Sampling Programme • Testing of at risk product and product contact surfaces at a higher frequency than routine microbiological monitoring • Purpose: • identify any at risk product that may have been contaminated at time of L. mono detection • test at risk product and product contact surfaces once processing resumes.

What product could be at risk? Previously processed product Last clear test from routine monitoring Lab result – L. monocytogenes detected on a sample taken at day 0 Routine monitoring, positive L. monocytogenes 0 P P 1 2 3 P P 4 5 6 7 P PC Days P PC P = product sample PC = product contact surface sample Samples

Testing at risk product: around time of the contamination event • What product could be considered at risk? • since last not-detected result for Listeria species • on same processing line • on same day or day before the positive result • between taking the positive sample and notification of Lm • on processing lines close to contaminated line • processed under abnormal conditions e. g. failure at a CCP

How can you narrow the range of at risk product? • Process and supporting system records • results from past testing • results from environmental investigation (if available) • knowledge of process flow and production schedules

At risk product: around time of contamination event PCS positive: sample size per batch of at risk product type Low risk Medium Sample High risk Product n=5 n=5 Product positive: sample size per batch of at risk Sample type Low risk Medium High risk product risk Product n=5 n=30 n=60

Testing once processing resumes • Use results of investigation to date to narrow the range of at risk product • Sample at risk product during processing based on random times or hourly • Sample product and product contact surfaces at the same time • For product with a short shelf life testing may need to occur on trial batches

Testing of at risk product and PCS once processing resumes PCS positive: sample size per batch of at risk product type Low risk Medium Sample High risk Product PCS n=5 n=5 n=5 Product positive: sample size per batch of at risk Sample type Low risk Medium High risk product risk Product n=5 n=30 n=60 PCS n=5 n=5

Intensive Microbiological Verification • Commences after 3 days of “notdetected” for Listeria at intensive sampling size • Continue for 4 days to give confidence that Listeria has been controlled • Minimum suggested sample sizes given • If a positive returned, resume intensive

Continued Detections? • Response to be escalated • Usually indicate bigger more persistent problems • Halt processing on the contaminated line(s) • Engage external expert to review actions and assist in resolution • Where processing continues, all affected product at risk • Consider expanded recall • Continue investigation into cause

Sample sizes • Suggestions only but justification expected where smaller sample sizes taken • As number of samples decrease, chance of accepting an unacceptable product batch increases. • Costs involved in sampling and testing weighed against impact of making an incorrect decision • Regulator to be involved in decisions on sample size

Micro Testing • For product that will not support the growth of Listeria and that has a limit of 100 cfu/g, having the laboratory enumerate the Listeria could be used to assist in determining product disposition • Lm may be further differentiated to help to determine whether the same or a new type of Lm is contaminating product contact surfaces and/or the product. • By comparing the different DNA patterns you can see if: • there is a recurring ‘house’ Lm which will have established itself in a niche or harbourage site or • there are different DNA fingerprints of Lm it suggests that contamination is being introduced, e. g. from the external environment, ingredients, equipment, personnel.

Corrective Actions • Dispose of contaminated and at risk product • Prevention of recurrence and review of LMP after the event • Documentation, records and reporting

Thank you