Recent years have seen increasing focus on virus infections transferred to humans through food or water. The most well-known virus is Norovirus or Norwalk-like virus infections, which is a highly contagious, acute gastrointestinal infection with strong emesis and watery diarrhea.

Denmark has experienced several outbreaks of Norovirus during the past couple of years, many of them linked to ingestion of imported fresh raspberries, oysters or lettuce. But food items that are eaten raw, most often berries, fresh produce and raw shellfish are generally known to be potentially contaminated and may transmit the infection to humans.

Most outbreaks of the Norovirus have occurred in connection with buffets, canteens, or private parties.

As it is in very high numbers by diseased persons, up to a billion virus particles per gram faeces while the infective dose is very low, down to 10-100 virus particles, Norovirus is extremely contagious. This implies that food items contaminated with only low numbers of virus particles may cause disease. This poses some demands on the detection methods, which must to be very sensitive.

At the National Food Institute, Technical University of Denmark, we work with methods for detection and quantification of food and waterborne viruses in matrices such as berries, shellfish, fresh produce, water, air and surfaces. We work both on purification methods and on detection using PCR technology, and, if required, a further characterisation of the virus by sequencing.

The analyses are used for research purposes and as a part of our consultancy services to the food authorities. However, analyses and consultancy are also offered to external costumers that may wish to have their food products tested for viruses.

Another human pathogenic food and waterborne virus that should be mentioned is hepatitis A virus.


Danish Veterinary and Food Administration
Dianova, Aarhus, Denmark
University of Copenhagen, Faculty of Life Sciences, Denmark
Statens Serum Institut, Copenhagen, Denmark
Technological Institute of Denmark, Roskilde and Aarhus
National Research Centre for the Working Environment, Copenhagen, Denmark
Danish Agriculture and Food Council, Copenhagen
Swedish Institute for Infectious Disease Control, Stockholm
National Food Agency, Uppsala, Sweden
Kretsloppskontoret, Gothenburg, Sweden
Norwegian School of Veterinary Sciences, Oslo, Norway
CEFAS, Weymouth, England
Centers for Disease Control and Prevention, Atlanta, USA
29 OCTOBER 2020