It was just after school started in mid-August that the children were served tortillas. Soon after, many students became ill with symptoms such as stomach ache, nausea and headache. Some children vomited.
In the worst case, the children suffered from fever, muscle aches and diarrhoea.
The Finnish public health authority, the Institute for Health and Welfare, together with the city’s environmental services, has investigated what triggered the cases of illness.
The conclusion after a survey is that most cases can be traced to the tortilla breads. Those who ate tortilla bread fell ill three times as often as those who chose something else.
Laboratory tests show that some breads smelled of vinegar, but what caused the incident is still unknown – the investigation continues.