Three European countries have recorded Listeria infections with fish being investigated as the source.

Germany has reported 30 infections and, since November, two people in Austria and one person in Denmark has contracted the same strain of listeriosis.

In Germany, patients were notified and transmitted to the Robert Koch Institute (RKI) from the end of September to mid-November. They are 38 to 93 years old and 26 people were hospitalized. One person died but a detailed cause of death was not reported.

In Denmark, there is no exposure information available for the one patient. The Listeria monocytogenes isolate has the sequence type (ST) 394 and is very rare among Danish patients.

Source under investigation
In Austria, the foodborne disease outbreak investigation involves the Austrian Agency for Health and Food Safety (AGES), Federal Ministry for Social Affairs, Health, Care and Consumer Protection (BMSGPK) and relevant regional authorities. Officials said initial investigation findings point to chilled smoked trout fillet from Denmark as the source.

However, a spokeswoman for RKI in Germany said investigations to confirm the source are ongoing.

“RKI currently conducts patient interviews and for us a slightly different picture might emerge. Not all patients recalled trout consumption and different retail chains were visited for food shopping,” she told Food Safety News.

“The outbreak clone is a Listeria monocytogenes strain belonging to serogroup IIa, a Listeria monocytogenes serogroup that is commonly associated with listeriosis in humans. Whole genome sequencing classifies this strain as a new genetic subtype, not detected previously, but the strain does not represent a novel species or any other novel type of pathogen.”

Lidl recall and manufacturer’s view
German authorities have informed member states via the Rapid alert System for Food and Feed (RASFF) that Listeria has been detected in chilled smoked trout fillets from Denmark.

The supermarket Lidl in Austria and Germany has issued a product recall for all use by dates of two types of smoked trout fillets from the Danish manufacturer Agustson.

Nautica Regenbogen Forellenfilets 125-gram in the varieties of natural and with pepper are affected and have DK 4566 EG on the package.

Agustson CEO Esben Andersen said the company has not agreed to a product recall.

“All sampling of our finished products including sampling of our retained samples show negative Listeria results. All laboratory results — including the lab reports sent to us by Lidl — certify that our products are suitable for human consumption.”

Andersen added the recall was not done by German authorities but Lidl decided to take such action on its own initiative.

Meanwhile, Austrian authorities reported another possible Listeria outbreak.

Since the beginning of 2020, three people in Styria have contracted an identical Listeria strain. As the cases are relatively close in time, a foodborne outbreak cannot be ruled out and AGES was asked by authorities in Styria to investigate. As yet there is no indication of the source.