Thirteen people have been infected with Salmonella across Norway but the source has not yet been identified.
Folkehelseinstituttet (The Norwegian Institute of Public Health) said Salmonella Enteritidis infection has been detected in people living in several counties.
The agency is investigating with local authorities, Veterinærinstituttet (Veterinary Institute) and Mattilsynet (Norwegian Food Safety Authority).
Patient samples were taken in late July and early August. Bacteria with similar DNA profiles have been detected in all 13 individuals suggesting a common source.
There are seven women and six men affected, aged 10 to 73 years. They live in Oslo, Nordland, Troms, Finnmark, Rogaland, Vest-Agder, Vestfold, Trøndelag and Oppland.
Folkehelseinstituttet officials said there is no link to past outbreaks of Salmonella Enteritidis in the country such as the one traced to Polish eggs in 2016 and 2017.
The investigation includes interviews with patients and samples of food and leftovers being taken to try and find the source of infection.
Solveig Jore, senior adviser at Folkehelseinstituttet, said outbreak investigations can be complicated and take time.
“In many cases you will not be able to find the source of infection or to clarify if there is one common source. It is too early to say something about if this is a limited outbreak or whether it will increase in scale, but we are following the situation carefully,” she said.
Each year, between 900 and 1,300 cases of salmonellosis are reported to Folkehelseinstituttet, with most people having been infected abroad. Prevalence of Salmonella is low among Norwegian livestock and Norwegian-produced foods, compared to most other countries in Europe.
Norway was affected by an outbreak of E. coli O157:H7 with eight people ill in June and July of this year. The country also reported an outbreak of Yersinia enterocolitica O:9 with 18 people diagnosed with infection in June. In both cases a common source of infection was not found.
Sweden E. coli update
Meanwhile, the confirmed cases in an ongoing outbreak of E. coli O157:H7 in Sweden have jumped.
A total of 92 people are now infected from the 54 confirmed and 50 suspected cases reported last month.
The majority of people fell ill in July with the latest date of illness onset being Aug. 10. Patients come from nine counties but the majority live in Uppsala and Västra Götaland.
An additional 10 cases are being investigated for connection to the outbreak. Remaining suspected cases have an EHEC infection where epidemiological or microbiological connection to the outbreak has not yet been confirmed or ruled out.
Folkhälsomyndigheten (Public Health Agency) and Livsmedelsverket (National Food Agency) are continuing to try and find the source or sources of infection.
Patients are being interviewed about what they ate before they became ill and common foods traced back via the supplier and wholesale to the producer but for the moment no certain connection with any suspected foods has been established.
In Sweden, more than 500 EHEC cases are reported in people every year, with primarily children under five years of age infected.
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