Photo: Mikkel Adsbøl

Denmark continues to have many foodborne infections and outbreaks

Monday 07 Oct 19


Birgitte Helwigh
Senior Scientific Officer
National Food Institute
+45 40 21 19 62


Helle Bisgaard Korsgaard
Senior Academic Officer
National Food Institute
+45 40 21 20 17


Luise Müller
Statens Serum Institut
+45 32 68 85 90

The 64 reported foodborne disease outbreaks in 2018 included two rare and serious outbreaks, according to the annual report on the incidence of foodborne diseases in Denmark for 2018. The report also shows that the vast majority of imported cooked prawns from Asia are contaminated with bacteria of fecal origin.

Campylobacter remained the leading cause of foodborne infections in Denmark causing 4,546 reported cases of human disease in 2018. Salmonella was in second place causing 1,168 reported cases of illness.

This is one of the findings of the annual report on the incidence of foodborne diseases in Denmark. The National Food Institute, Technical University of Denmark, has prepared the report in cooperation with Statens Serum Institut, SSI, and the Danish Veterinary and Food Administration. SSI is the Danish national institute for surveillance and preparedness of human infectious diseases.

Serious foodborne illness outbreaks

In 2018, 64 outbreaks of foodborne illness were reported, which is similar to the previous year, in which 63 outbreaks were reported. The outbreaks in 2018 made 1,600 patients sick, which is much more than the 1,151 patients who got sick in the outbreaks in 2017. This was mainly due to three large outbreaks in 2018, which caused approximately one quarter of the outbreak-related cases.

Two rare and serious outbreaks were reported in 2018: Firstly, a large outbreak of infectious hepatitis caused by the hepatitis A virus in dates. Secondly, a nine-patient botulism outbreak was caused by a homemade, savoury jelly dish.

“The figures from 2018 show that Denmark still experiences serious outbreaks that need to be investigated and stopped. The successful investigations of the large national outbreak of hepatitis A from Iranian dates and the local botulism outbreak show the importance of Denmark’s interdisciplinary preparedness, which can handle such unforeseen incidents,” epidemiologist Luise Müller from SSI says. 

Widespread contamination in cooked prawns

The report also shows that more than 75% of cooked Asian prawns analysed in a survey were contaminated with fecal bacteria. The National Food Institute and Danish Veterinary and Food Administration looked for enterococcus and E. coli bacteria in 300 samples of pangasius fish as well as raw and cooked prawns from Asia.

“These types of bacteria do not necessarily cause disease. However, their presence indicates that the prawns have either not been sufficiently heat-treated to kill bacteria that may be present, or that the bacteria have been introduced during the processing or packaging,” Senior Academic Officer Birgitte Helwigh from the National Food Institute says.

”When you find bacteria of fecal origin, there is the risk that disease-causing microorganisms—such as salmonella—may also be present in the product,” she adds.

All of the pangasius samples and approximately 94% of the raw prawns contained the two types of bacteria. However, these products require heat treatment before consumption. As such, the National Food Institute considers the risk of getting sick from these products lower than the risk related to the cooked products, but there is always a risk of cross-contamination during preparation if the product contains disease-causing bacteria. 

The samples were also analyzed to determine the occurrence of antimicrobial resistance. The analyses showed a low occurrence of critical resistance, which is resistance to the types of antimicrobials that are important in the treatment of serious human infections. These data are included in DANMAP 2018, which was published in September 2019.

Read more

Read the whole report on the National Food Institute’s website: Annual Report on Zoonoses in Denmark 2018 (pdf). You can also have the printed report sent to you by contacting Secretary Anne Jørgensen,

This year’s Annual Report does not contain a salmonella source account. It is the first time since 1994 this has happened and it is mainly due to technical challenges relating to data, as the model has been further developed to use whole genome sequences.

Download the DANMAP report for 2018 from the DANMAP website. The report presents findings from the DANMAP programme, which monitors the use of antimicrobials in humans and animals in Denmark, and the occurrence of antimicrobial resistance in bacteria in animals, people and foods.
10 APRIL 2021