An outbreak of Yersinia in Denmark and Sweden with more than 50 cases has been linked to fresh spinach. Statens Serum Institut, a public health research institute in Denmark, reports 20 people have been infected in the country. One person needed hospital treatment. The Public Health Agency of Sweden (Folkhälsomyndigheten) has recorded 37 confirmed cases.
In March, 20 cases of Yersinia enterocolitica were found in Denmark. There were 11 women and nine men aged 2 to 74 years old, with most cases aged 20 to 30. Patients were distributed throughout Denmark in Hovedstaden, Sjaelland, Syddanmark, Midtjylland, and Nordjylland.
The link to spinach was based on a case control study and the trace-back investigation, which is still ongoing to determine which country the spinach came from. After interviews with patients, Statens Serum Institut did a study in which healthy people of the same gender and age, and who lived in the same municipality as those sick, were asked if they had eaten certain foods that many of the Yersinia patients ate. The study showed patients had consumed fresh spinach to a far greater extent than the control people.
The investigation found spinach was bought in Netto and a supermarket chain in Sweden. Danish officials said the implicated product is no longer on the market because the country had not seen any cases since March and given duration of the outbreak it was likely only one batch that was contaminated.