Rock County has its first known case of COVID-19. Officials don’t expect it to be the last.

The case was announced via news release by the Rock County Public Health Department on Thursday evening.

The person infected is 57 years old and is isolated at home, according to the release.

Officials were careful not to say where the person lives or other personal details out of privacy concerns, but at one point in a telephone conference Thursday night, one department official referred to the person as female.

Officials did not know how the person became infected, They said there was no known direct contact with a positive case, but they suspect it could have happened when the woman attended events in Chicago.

They did not know when or where she attended the events, or how she traveled to and from Chicago.

A department nurse was on the phone with the woman Thursday night, asking questions and identifying people with whom the woman had been in close contact (within 6 feet), officials said.

Anyone who has been in close contact will be asked to self-quarantine, officials said.

State officials reported two deaths from the virus Thursday. The first death was a man in his 50s from Fond Du Lac County. The second death was a man in his 90s from Ozaukee County, according to a release from the governor’s office.

The Rock County woman was tested Monday, and the health department received notification from a state disease surveillance system Thursday, officials said.

The health department would not say where the woman was tested because of privacy concerns.

Among the many questions officials couldn’t answer were whether the woman had traveled with anyone to Chicago, what symptoms the woman had, why she was tested, whether anyone else lives in her home and how long she might be in isolation.

In isolation, an infected person never leaves the home, separates herself from others in the home as much as possible, wears a mask when close to someone, avoids touching household items and washes her hands, said public health nurse Olga Myers.

Rock County Health Officer Marie-Noel Sandoval said she expected Rock County will see more cases. She noted most surrounding counties have reported positive tests.

“I don’t truly believe this was unexpected,” Sandoval said. “We assumed that eventually we would have some positive cases in Rock County.”

When asked about how many people in Rock County had been tested, officials said they receive only information about how many positive and negative tests had come back. Those numbers Thursday night stood at 46 negative and one positive.

Sandoval said Interstate 90/39 could bring travelers carrying the virus to Rock County, but she said the fact that the county is largely rural helps keep infections away.

“I also believe we worked with our partners in the community early on to provide them with information to help protect themselves, so I think that’s all on our side,” Sandoval said.

Sandoval complimented county residents for maintaining physical distance from others and following other recommendations of health authorities.

“It’s for your own safety, and just keep doing those same things,” Sandoval said.

Testing for COVID-19 is being done in Wisconsin through the Wisconsin State Laboratory of Hygiene at UW-Madison, at the Milwaukee Health Department and at private labs throughout the state, according to the news release from the governor’s office.

Right now, Wisconsin is prioritizing testing for COVID-19 because of a shortage of testing materials.

“It is important that we reserve our testing capacity for individuals who are critically ill and healthcare workers on the front lines. This will help us keep our healthcare workforce safe and healthy and help stop the spread of the virus,” the release from the governor’s office reads.

“Many states across the country are grappling with this same problem. We have been working with our partners in the federal government, in the private sector, and our public universities to try to get the ingredients needed to run these tests,” the release reads.