According to the test results, the winter vomiting disease caused the infection, Eva Lindgren, assistant infectious disease physician at the Västra Götaland Region, told P4 Gothenburg.
The first reports of people falling ill were received on Sunday. Symptoms have included severe vomiting, fever, diarrhea and body aches.
Such large outbreaks are unusual, Lindgren says, adding that norovirus, or winter vomiting disease as it is also called, can be found in food.
Which food caused the outbreak in this case is still being investigated by municipal food inspectors.
