By Robert Herriman  @bactiman63

In a follow-up on the Yersinia enterocolitica outbreak ongoing in Sweden and Denmark, health officials from both countries in this cross-border outbreak to a cumulative total of 57.


In Sweden (computer translated), the outbreak tally has reached 37, as of May 3. Health officials say that previous suspicions of a link to Latvian carrots has proven to have no connection.

Sweden has begun a case-control study to search for foods that the disease cases have eaten and which differ from what controls have eaten.

While in Denmark (computer translated), a total of 20 people are part of the outbreak. The investigation shows that the source of infection was probably fresh spinach.

After in-depth interviews with the patients, Statens Serum Institut initiated a study in which healthy subjects with the same sex and age were also asked, and who lived in the same municipality as the sick, if they had eaten certain foods that many of the sufferers had eaten. The study showed that the patients had eaten fresh spinach to a far greater extent than the controls.

The study also points out that the spinach has been bought in Netto and in a supermarket chain in Sweden. It is probably about foreign, fresh spinach sold in March. The spinach is no longer on the market.

The outbreak strains in the two countries are the same and a joint investigation is ongoing.

Yersiniosis is due to infection with the bacterium  Yersinia enterocolitica . The most common symptoms are diarrhea, fever and abdominal pain, usually of 1-3 weeks duration. The reservoir for the bacterium is primarily pig. Dog and cat can also be carriers of the bacterium.

Yersinia bacteria mainly contaminate food, usually via infected pork products, contaminated vegetables or salads, and the use of non-disinfected drinking water.