Minnesota health officials said Wednesday that an outbreak of Norovirus in Winona County has sickened approximately 30 people during the past 10 days. Doug Schultz of the Minnesota Department of Health said that illnesses probably began around Sept. 23, although the department learned about them on Sept. 30. He said the illness, which causes vomiting and diarrhea, was confirmed in people who ate at Winona’s Ground Round restaurant. Restaurant owner Tim Beier has voluntarily closed the business to thoroughly clean everything. “We have been in 100 percent full cooperation with the health department,” Beier told the local press. Schultz advised people to wash their hands frequently, stay at home if they’re sick, and wait 24 hours after symptoms subside before returning to work or school. He noted there are about 40 outbreaks of foodborne illness in Minnesota each year and that approximately 60 percent of them are Norovirus, especially in the fall and winter.