Almost 450 people have fallen ill in Finland with salad from Sweden suspected to be the source of infection.

Officials in the city of Jyväskylä are investigating Salmonella cases and absence of children and staff at preschools and private day care centers who reported symptoms of infection, with the help of the National Institute for Health and Welfare (THL). In total, 377 children and 65 adults have been affected.

On Tuesday, only a few new cases were reported, so the outbreak appears to be slowing down, said investigators. Initially up to 100 children were thought to have fallen ill in recent weeks with many going to to hospitals but not needing admission.

Patients attend or work in different preschools that outsource meals. The incident has been estimated to have affected one in seven of the 2,500 children potentially exposed.

Investigation findings
Produce served at lunch on June 18 has preliminarily tested positive for Salmonella. This included foreign iceberg lettuce, domestic fresh cucumber and domestic frozen peas. Confirmatory testing on which ingredient was contaminated is continuing with results expected in the next few days.

Suspicion has fallen on the iceberg lettuce that comes to the central kitchen ready to use in bags and does not undergo further processing. Potential contamination could have occurred during primary production with irrigation water or at the Swedish plant wher it has been processed and bagged.

An investigation is ongoing with the wholesaler that supplied the vegetables and the Swedish iceberg lettuce manufacturer, who will send their own samples for examination of batches that may have been sent to the central kitchen on the implicated dates.

A company called Kylän Kattaus, which provides food services in the city, has stopped using imported iceberg lettuce for the time being.

Tuija Sinisalo, director at Kylän Kattaus, said lessons can be learned to avoid repeat incidents.

“We are hugely sorry for the sick children and adults and all the family members. We ourselves are shocked that even though our professionals have done everything in the central kitchen according to the instructions and regulations, this happened,” Sinisalo said.

More attention has been put on hand hygiene in kindergartens and cleaning of these places has been intensified.