Oregon Gov. Kate Brown said Thursday morning that the state should be prepared for thousands of cases of COVID-19 as coronavirus continues to spread throughout the state.

“My first order of business is to protect the health of Oregonians,” Brown said in a press conference in Portland. Second, she said, is helping businesses across the state of Oregon and she is bringing together business leaders to determine how to do so.

Late Wednesday night, Brown’s administration announced a statewide ban on gatherings of more than 250 people. The governor clarified Thursday that only applies to organized events, not places “such as stores, shopping centers or schools."

Schools are not covered by the ban but large meetings, assemblies and competitive events such as athletics must stop and sick students and employees should stay home, the governor said.

Dr. Jennifer Vines, lead health officer for Multnomah, Clackamas and Washington counties, said health and elected officials face an ongoing challenge in deciding how far to take social distancing policies, including the question of whether to close schools.

"I have no illusions about the bitter pill this is to swallow for our communities,” Vines said at the press conference. “You hear public health saying education is important, business opportunities are important, social connections are important. And unfortunately we have to look ahead at what’s happening in Washington and Italy ... If we start seeing crowded emergency departments and full intensive care units, by then it’s too late for these social distancing measures to have much impact.”

Patrick Allen, director of the Oregon Health Authority, reiterated the state’s warning to people most at risk of severe health effects from the virus, older Oregonians and those with underlying medical conditions. “You should stay home as much as possible," Allen said. “We can’t emphasize enough how dangerous this is for people who are at risk.”

Dr. Dean Sidelinger, the state’s epidemiologist, said that without taking such measures the state could reach as many as 75,000 cases of COVID-19 by mid-May. That figure was based on the number of Oregon cases, which Sidelinger estimated at 150 to 250, doubling every week, he said. Only 21 Oregonians are known to have tested positive so far, but very limited testing means most cases have gone undetected, he and other experts say.

As reporters pressed public health officials about Oregon’s very limited capacity to test people who may have the virus, Brown initially said she would like to have more testing available “but my understanding, at least according to public health professionals, is that we have an adequate amount.” Minutes later, Brown revised her position, saying, “We are concerned, frankly, about our testing capacity ... The federal government is only one who can expand our testing capacity and we are calling on them to do that.”

Sidelinger said the state public health lab can perform 80 tests per day and will stick with testing only people who are hospitalized and seriously ill and people exposed to others confirmed to have the disease. Labs generally test two samples from each person. He said commercial laboratories are able to test additional Oregonians but said he does not know even a rough estimate of what private labs’ capacity is. He said multiple hospital systems in Oregon will begin testing, but he said that will take time and predicted it would start within a week.

Allen, director of the Oregon Health Authority, said a state “strike force” has been deployed to the veterans senior care facility in Lebanon where two patients in their 80s have tested positive for COVID-19. But he said the approximately 150 residents and nearly 225 employees and others associated have not yet been tested for the virus.

He said the testing at the veterans home began Wednesday and might be completed “over the next couple of days." With the state only able to run 80 tests per day, the Lebanon testing could mean no one else in Oregon can be tested by the state’s public health laboratory for days on end.

Sidelinger said the state is counting on commercial labs, not its own public health lab, to expand the capacity to test the many, many Oregonians who want to know if they and those they live and work with have coronavirus. Public health officials do not know how many tests the private labs can process on a daily basis; Sidelinger suggested a reporter contact the diagnostic company LabCorp with that question.

Questioned repeatedly about the state lab’s limited capacity, Sidelinger and Allen emphasized the planned reliance on commercial labs, which he characterized as normal during an epidemic. Allen said the state needs to preserve its capacity for “surge testing” potential clusters of cases, such as at the veterans home.

The governor called the situation a “rollercoaster” and emphasized that she and other state and local officials are moving swiftly.

In response to a reporter’s question about whether large weddings with more than 250 attendees are banned, Brown said they are. Allen was less clear when asked whether other large outdoor gatherings, such as the Portland Saturday Market. “That’s one that we’re going to have to see how it plays out in practice,” Allen said.

36 Governor Brown addresses coronavirus concerns, initiatives

Brown, state Sen. Lew Frederick of Portland and state health officials were joined at the press conference by Portland area officials, including Multnomah County commissioners, Portland Public Schools Superintendent Guadalupe Guerrero and Portland Mayor Ted Wheeler. The mayor announced the city’s own emergency declaration, which allows the mayor to “assume centralized control” and authority over all city bureaus and departments, and said he is working with the city’s economic development agency Prosper Portland to develop a stimulus plan. Wheeler said city officials have not yet decided whether to cancel public meetings. Multnomah County declared an emergency Wednesday.

Officials cut off their news conference after less than an hour, leaving many questions unanswered as concerns mount in Oregon, nationally and worldwide about the pandemic.

-- Hillary Borrud; hborrud@oregonian.com