Notified foodborne outbreaks halved in Norway in 2020 compared to the year before.

The Norwegian Institute of Public Health (FHI) received 23 notifications about outbreaks this past year compared to 46 in 2019.

Norovirus, Cryptosporidium, Salmonella and Yersinia were all reported three times each while the agent was unknown for five outbreaks.

A total of 495 people were sick in connection with the outbreaks. The number of patients in each one varied from two to 180 people with a median of 10.

In total, 212 people were sick in the trio of norovirus outbreaks, 70 for cryptosporidium and 46 for Yersinia.

The Salmonella outbreaks were caused by Salmonella Enteritidis, Salmonella Newport and Salmonella Oranienburg and affected 46 people.

Clostridium caused two outbreaks with 16 cases while one Campylobacter outbreak affected 10 people and one Listeria monocytogenes epidemic sickened four, but the source was not found.

Most foodborne outbreaks were reported in relation to restaurants, cafes and other places of dining.

Vegetables, herbs and products were linked to three outbreaks, homemade rakfisk, a traditional Norwegian fermented fish product, caused two cases of botulism but the type of food was unknown for 18 outbreaks.

Another report found foodborne diseases dropped overall in Norway in 2020 but there were domestic increases for Campylobacter, Cryptosporidium and Yersinia.

Example outbreaks
In early January 2020, there was an outbreak of cryptosporidiosis. Employees at two different businesses became ill after a Christmas lunch delivered by the same catering company over two days.

about 100 people had attended the lunches, and 62 reported they had diarrhea shortly afterward. Illness was laboratory confirmed for five people. The source of infection was not identified, but contaminated lettuce or infectious people were considered the most likely source.

A Yersinia enterocolitica outbreak affected 25 people in summer. The 17 women and eight men aged 2 to 58 years old became ill from mid- to the end of May, except for one case which had a date at the end of June.

Patient interviews showed that 23 of 25 cases had eaten a pre-washed salad product that contained baby spinach or spinach the week before illness. However, the source of infection could not be confirmed through microbiological testing.

Another Yersinia enterocolitica outbreak sickened 10 people from mid to late November. Patients lived in different parts of the country but all were women aged 11 to 59 years old. The source of infection was probably some type of pre-cut lettuce product.

In mid-December 2020, there was an outbreak of Salmonella Newport in Trondheim.

The outbreak strain was detected in 12 cases and 10 of them were associated with a company canteen in Trondheim. Iceberg lettuce imported from Spain was considered the most likely source.

Salmonella Newport with the same whole genome sequencing results was also detected in four patients living elsewher in Norway. Three were interviewed and all had been ill at the same period from the end of November and in December but the source of infection could not be verified.