BOISE (AP) — Idaho health officials said Friday that the state’s first case of the new coronavirus is a woman in her 50s in southwestern Idaho in highly populated Ada County, which includes Boise.

Gov. Brad Little said the positive test doesn’t change anything at the moment because she contracted the virus at a conference in New York City, so it’s not a case of community spread where the source is unclear.

Health officials said the woman, whose name wasn’t released, is self-isolating at home and has mild symptoms. Officials are checking the people she has had contact with, but they said the threat to the community is low.

The woman attended the conference from late February to early March, and flew back to Boise. Officials said other passengers on the plane likely had little risk of catching the virus because the woman wasn’t showing signs of being ill.

The news came several hours after Little declared a state of emergency.

The Republican governor said he wanted the state to be prepared and guard against healthcare systems being overwhelmed. The emergency declaration would be in effect for 30 days but could be extended.

Little said his declaration has two primary goals. The first is to prevent infections and slow the spread of the virus in the state’s 1.8 million residents so that healthcare facilities will have the capacity to care for those who become seriously ill.

“If too many people get sick too soon, our healthcare facilities will not have the capacity to deal with it,” Little said.

The second goal is to help protect the most susceptible, who are the elderly and those with existing health problems.

State officials say more than 100 people in Idaho have so far been tested, but until Friday no one had been found positive for COVID-19, the illness caused by the new coronavirus.

State Epidemiologist Christine Hahn said models she’s using indicate that from 15% to 35% of Idaho’s population could be infected. That means from roughly 270,000 to 630,000 residents.

Even a small fraction of them showing up in hospitals all at once would stress the system, officials said.

For most people, the coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia. The vast majority of people recover within a few weeks.

The declaration makes money available and gives Little flexibility in responding to situations around the state. He said he has received good help from the federal government.

Little’s declaration means Idaho will have access to protective gear for healthcare workers and ventilators for those who become severely ill.

State officials acknowledged that having just more than 100 people tested so far isn’t enough. But Hahn said Idaho’s testing for the coronavirus is ramping up, with three commercial labs recently taking part as well as the state lab.

“We’re in a tight pinch right now. But we think it’s going to improve as these private labs come on board,” she said.

Little said there are no plans to close schools or take extraordinary measures at the moment other than to ask people to use good hygiene to avoid getting the virus. He said protocols are in place for various scenarios should infections start appearing.

Superintendent of Public Instruction Sherri Ybarra said decisions about closing schools are being left to local districts, but that could change.

The State Board of Education was scheduled to hold a special board meeting later in the day to consider a potential response for colleges and universities to the virus.