The number of outbreaks and people sick in them in 2022 went up from the year before, based on new data from Norway.

A total of 34 foodborne outbreaks were reported in 2022, which is up from 23 and 25 outbreaks in 2020 and 2021 but lower than the 46 outbreaks in 2019.  

Overall, 628 people were sick this past year with the largest incident affecting 100 people, according to a report published by the Norwegian Institute of Public Health (FHI). In the 25 outbreaks in 2021, 327 patients were recorded.

Eight norovirus outbreaks sickened 135 people in 2022. Five outbreaks with 148 cases were caused by Salmonella. Cryptosporidium and Yersinia were behind three each with 14 and 51 patients, respectively.

Ten people were sick in two Listeria outbreaks. One Campylobacter outbreak had six patients and one E. coli event affected seven people. The agent was unknown for 11 outbreaks with 257 cases.

Most foodborne outbreaks were reported in connection with restaurants, cafes and other catering establishments.

Six outbreaks were linked to vegetable and herb products and five were caused by seafood such as shellfish or mollusks. One outbreak traced to pork products affected 37 people and another linked to fruit and berries had 21 patients. For 14 outbreaks, this information was not known.

Examples of Listeria and Salmonella outbreaks
Five patients were included in a Listeria outbreak, all were women aged 60 to 68 and living in two counties in Norway. They became ill around Christmas and New Year either from 2020 to 2021 or 2021 to 2022. Interviews indicated the source of infection could be a seasonal product but there was no single producer that could be identified, so the incident remained unsolved.

Five people were also sick in a separate Listeria outbreak. Samples came from February to October 2022. Three cases were men and the median age for all patients was 72 years old. Four cases had eaten smoked salmon prior to illness, with three mentioning the same producer, Troll Salmon.

The outbreak strain was detected in smoked salmon from the firm. Some environmental samples were also positive for Listeria monocytogenes. This prompted a product recall and the company stepped up measures to prevent contamination.

In another outbreak, 22 Salmonella Blockley cases were detected from seven counties. People became ill from November 2021 to February 2022. They were nine men and 13 women aged from 1 to 80 with a median of 38 years old. Fourteen people were hospitalized. Patient interviews did not point to a specific source of infection. Vegetables and salads were suspected and supply chains were investigated without officials being able to reach any conclusions.

An outbreak of Salmonella Typhimurium was also unable to be solved. Nine people fell ill in November and December 2021. Patients were five men and four women from 13 to 82 years old with a median age of 30. Four people were hospitalized.

A different Salmonella Typhimurium outbreak with 21 cases was linked to watermelon. Most samples were taken in July. Cases were aged 1 to 87 with a median of 54 years old and 60 percent were men. Eight people were hospitalized. Fifteen of 16 cases interviewed had eaten watermelon in the days before falling ill. However, no common supplier or batch of melons could be found.

A total of 89 people fell ill in a Salmonella Agona outbreak in November. They were aged 1 to 91 with a median of 37, and 50 were women. Thirty-one people were hospitalized. Sweden and the Netherlands also reported cases in the same period. Certain batches of cucumbers from a Spanish supplier were the likely source of infection.

Yersinia outbreak findings
One Yersinia enterocolitica outbreak was linked to food served at a school. Of 37 cases in the outbreak, 33 were connected to the school and they fell sick in late January 2022. Two meals served from a restaurant connected to the site stood out as possible sources of infection. Samples of pork, from the same batch served in one of the meals, were positive for the outbreak strain.

Another Yersinia outbreak affected nine people in the first three weeks of June. Cases were aged 12 to 57 and six were men. Two people were hospitalized. The likely source was a type of salad but this was not confirmed.

Finally, people were ill in late November following a two-day conference held in Stavanger, where food from two catering businesses was served. Based on questionnaire responses, 48 people, who attended day 1 of the event, became ill.

Many had eaten salads at the lunch buffet or from fruit platters served during a break but no food remained to be tested. In stool samples from three participants, Salmonella and two different types of Enterotoxigenic E. coli (ETEC) were detected. Officials said it was not possible to know if infection came from contaminated food or via sick employees or guests.

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