Julie Willems Van Dijk, deputy secretary of the state Department of Health Services, spoke to the possibility of school closings at the press conference earlier on Friday.

I think it's really important for families with school-age children to be using this as an opportunity to think about, what would I do if schools were closed, especially for an extended period of time," she said. "Where would my children go? Who would take care of them?"

She cautioned that many children are cared for by grandparents, which could create a risk because the disease is most serious and deadly among the elderly.

The 19 cases of confirmed coronavirus exposure extends the reach of the virus to seven counties. There have been six cases in Fond du Lac County, five in Dane County, three in Sheboygan County, two in Milwaukee County, and one each in Racine, Pierce and Waukesha counties.

Westergaard said investigations into the new cases are still in the early stages. He said the those infected represent a range of ages, but most are adults. He didn’t have information on whether any of the cases were severe, which is more likely among the elderly and people with other health concerns. Several people in U.S. nursing homes have died.