Dansk Supermarked Group issued a recall after Fødevarestyrelsen (Danish Veterinary and Food Administration) detected Listeria monocytogenes in two packs of cold-smoked salmon from BK Salmon in Poland.
L. monocytogenes was identified at 240 CFU/g in chilled cold smoked salmon.
The first food sample was taken as a part of a DVFA monitoring and control project for 2017 on L. monocytogenes in ready to eat products at retail level.
As a follow up, samples were taken from two other batches of the same type of product from the Polish establishment to assess if there might be a persistent problem.
An additional sample from one of those batches was then found positive with L. monocytogenes.
Bacteria found in patients and food
The bacteria is the same type found in four patients. Three became ill within one week in August and the fourth fell ill in May.
Three women and one man have been sickened from across the country with the age range of 55-96 years. Interviews with three patients showed that smoked salmon was the most likely source.
Three of them have severe underlying disease and one has died.
The DVFA told us the recall is completed and it appears that only Dansk Supermarked Group received products from the Polish establishment.
“The DVFA has taken samples of other batches of the product and of other products from the same supplier. We are still awaiting the results of these samples.
“We are still awaiting information from the Polish authorities concerning their investigation and the distribution of possible affected products. The products were packaged in Poland. There has been no processing or handling of the product in Denmark which could cause contamination.”
DVFA said it is too early to conclude that the outbreak has stopped and to start an investigation at least two cases has to be identified.
“The investigation has gone through the normal procedures and we have had no specific leads until SSI, DTU Food and DVFA found a match between the human cases and a sample taken from the batch of polish cold smoked salmon that is now recalled.
“Isolates from food are sampled, tested and sequenced by the DVFA. In case of an outbreak the WGS data from the food analyses are shared with DTU Food and SSI in order to compare with the human sequences.
“The last couple of years the DVFA has put a great effort into combatting outbreaks caused by Listeria, together with the industry and other stakeholders. This resulted in the number of Listeria cases dropping last year and we are certain that this is the result of this united effort.”
Spike in Listeria cases
Steen Ethelberg, senior scientist at Statens Serum Institut, said it was quite possible more cases would be identified but the presumed source had been found.
BÅDSMAND RØGET LAKS, 125g; BÅDSMAND Gravad Laks, 125g; BÅDSMAND RØGET Lakserester, 150g; ØGO RØGET Laks, 100g; Levevis RØGET Laks, 100g; ØGO RØGET Laks M. Peber, 100g; Premieur RØGET Laks, 100g; Premieur Gravad Laks, 100g; Premieur RØGET Laks, 200g and Premieur Gravad Laks, 200g sold in Netto stores.
Princip RØGET Laks 100g; Princip Gravad Laks 100g; Princip RØGET Laks 200g; Princip Gravad Laks 200g; Princip RØGET Laks 300g; Levevis RØGET Laks M/Peber 100g; Levevis ØKO RØGET Laks 100g; Budget RØGEDE Lakserester 150g; Budget RØGET Laks 160g; Budget Gravad Laks 160g XXL Gravad Laks 500g and XXL RØGET Laks 500g sold in Bilka, Føtex and Salling stores.
“We don’t perform an investigation when there are sporadic cases. Last week there were three cases and we received isolates at SSI from patients in Danish hospitals and subjected them to characterization by whole genome sequencing,” he told us.
“Three cases ill at roughly the same time and almost identical by WGS is unusual, three cases in a week was obviously an outbreak. Interviews with the cases suggested a salmon product.
“We have a good cooperation with the Danish food authority and DTU Food who are responsible for WGS of food isolates and through cooperation we see if food isolates are genetically linked to cases.
“Generally it is globally well recognised that for Listeria infections salmon is on the list of classical sources along with cold cut meats and non-heat treated cured smoked meats.”
As it may take up to three weeks, from exposure to infection until symptoms appear, more illnesses related to the outbreak could occur.
Two packs positive but mass recall
Dansk Supermarked Group operates more than 1,400 stores in Denmark, Germany, Poland and Sweden and employs more than 50,000 people internationally.
It consists of the retail chains føtex, Bilka, Netto and Salling.
A spokesman told us it initiated a recall and removed affected product from around 600 stores in Denmark and a limited number in Metro Poland.
“Two individual packs were affected but we decided to remove everything with various dates to be on the safe side. The samples were slightly above the legal acceptable limit. We have other salmon products that are not affected,” he said.
“We are looking to substitute products as quickly as possible as smoked salmon is popular in Denmark. The salmon is from a Polish factory, we have worked with this factory for a number of years and the quality has been good. Unfortunately Listeria has been detected in some samples.
“As of now, there are no products from this factory but we have salmon from other suppliers. It is too early to say [if we will continue to work with them]. We know from examples across Europe that once Listeria is found it is difficult to completely get rid off.”