A Dutch broadcaster has revealed authorities had previously warned a company behind a fatal Listeria outbreak about problems with shelf life studies.

RTL Nieuws reported the findings after requesting documents about the incident from the Dutch Food and Consumer Product Safety Authority (NVWA).

Listeria in processed meats from Offerman, a Ter Beke subsidiary, made 35 people sick from 2017 to 2019. Two women miscarried and six people died. Ter Beke cited pending legal proceedings for not commenting on the report.

The shelf life set for some pate and cold meats was judged by the NVWA to be too long, according to RTL Nieuws. This means Listeria had longer to grow to higher levels in potentially contaminated products.

Responding to the article, an NVWA statement said the agency found “deficiencies” in shelf life studies in 2016 and 2017. This prompted an inspection and a warning because they were not in order. However, a re-inspection after three months did not happen as it should have, partly because of other priorities such as the fipronil in eggs crisis. The revisit and a fine did take place in September 2019, according to RTL Nieuws.

Changes to official supervision include a new intervention policy so fines are passed quicker, more attention to cleaning procedures and prioritization of re-inspection in comparable situations, said NVWA.

Low level Listeria findings

During inspections in 2016 and 2017, the NVWA discovered Listeria a few times but the risk assessment was low as presence of the bacteria was below the legal limit.

In July 2019, the National Institute for Public Health and the Environment (RIVM) detected a link between an outbreak and a product from Offerman. An investigation at the end of August revealed Listeria at higher levels than permitted but it was not clear at that time that Offerman was the source of the outbreak.

In October 2019, it was found the Offerman plant in Aalsmeer was likely the outbreak source. Listeria was found in the production area and in products. The investigation also pointed to deficiencies in cleaning procedures as the probable cause of contamination at the company. A recall was issued and the site closed in January 2020. Recall costs recorded by Ter Beke relating to the incident were almost €8 million ($8.9 million), according to the company.

Earlier this year, the fourth version of the European Union Reference Laboratory (EURL) for Listeria monocytogenes technical guidance document on challenge tests and durability studies for assessing shelf life of ready-to-eat foods for Listeria was published.

A limit of 100 colony forming units per gram (cfu/g) is set in EU regulation for RTE foods not able to support the growth of Listeria monocytogenes and for RTE foods able to support its growth when the manufacturer is able to demonstrate that its product will not exceed 100 cfu/g throughout the shelf-life.

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