More than 600 people have fallen ill in a suspected food poisoning outbreak at several schools in a Finnish city.

This past week, officials from the city of Mikkeli sent a questionnaire to parents of students and staff about symptoms that occurred during or after school meals on Aug. 16. As of Monday morning, answers had been received from nearly 3,800 parents and 350 employees.

All schools in Mikkeli have had at least a few patients. The incident is being investigated with the Finnish Food Authority (Ruokavirasto) and National Institute of Health and Welfare (THL).

Samples taken from different foods and raw materials are being examined to find out the cause of the epidemic. Results of laboratory tests are expected later this week.

Mainly mild illnesses
Most sick people had mild symptoms, which they have now recovered from, and as yet no serious illnesses have come to the attention of authorities.

about half of the students had symptom onset within an hour of eating, and 75 percent within six hours. about 16 percent came down with symptoms 12 hours after eating. The most common symptom was stomach pain, followed by nausea, headache, vomiting, diarrhea, fever, muscle or joint pain, and a few reported blood in their stool.

Ill staff reported stomach pain, nausea, headache, diarrhea, vomiting, fever, joint pain, and one person had blood in their stool.

Initial findings point to vegetable tortillas as the source, because there have been sick people at all schools wher they were available.

Several students mentioned the tortillas were “bad” with some saying they tasted like soap or detergent.

The tortillas came ready-made for all kitchens, from the same place. Vegetable filling was done for schools in four different kitchens.

In 2021, a large Salmonella outbreak in Finland affected more than 700 people, with children making up the majority of patients. The implicated food was a salad with iceberg lettuce, cucumber, and peas served in several education establishments. Officials in the city of Jyväskylä investigated the incident with the help of THL.