Oregon possibly acted on social distancing quickly enough to avoid becoming the next Italy – or New York – as long as Oregonians actually stay home.

New modeling released Thursday by the Oregon Health Authority shows the state’s hospital system appears capable of handling the coronavirus cases that are expected in the next month. But that’s just a planning estimate and assumes that nine out of 10 Oregonians stay home.

“We know that is going to be very hard to achieve in the short-term and probably hasn’t been achieved,” said Dean Sidelinger, Oregon’s state epidemiologist, “and will be very difficult to achieve in the long term.

“We know that the only way to get that curve to be flat or go down is aggressive action that people listen to.”

If followed strictly, Gov. Kate Brown’s March 23 stay-home order appears to be strong enough to not just slow the growth of coronavirus cases in Oregon but to reduce the number of infections, estimates from the Institute for Disease Modeling show.

The Bellevue-based research center is part of the Global Good Fund, a collaboration that involves Bill and Melinda Gates. As of Monday, it estimated that Oregon had about four times more cases than have been diagnosed.

By May 8, the institute projects, only a “small number” of inpatient beds will be needed in Oregon hospitals, driven by cases coming into the state from elsewhere.

Hospitals across the state have launched a massive campaign to prepare for the rapidly spreading global pandemic. Oregon built a 250-bed field hospital at the state fairgrounds to expand capacity. Sidelinger said despite the model’s projections, the preparation was still essential, in part because the modeled demand assumes that Oregonians follow the state’s orders -- and hospitals need to be ready for a surge if they don’t.

If Brown had taken no action at all and allowed the novel coronavirus to spread freely, estimates have shown, Oregon hospitals would have seen a surge of as many as 1,000 COVID-19 patients needing beds by mid-April.

While school closures and other initial restrictions helped reduce that number, estimates show that Oregon’s number of cases would continue to grow – just more slowly.

To date, at least 90 Oregonians have been hospitalized with the coronavirus, out of 318 cases statewide. And at least 11 Oregonians have died.

The estimates show that Oregon is poised to successfully buy time to allow for an increase in testing capacity and other measures needed to fight the virus. But how long it needs to buy time isn’t clear.

“We emphasize the urgent need for enormously increased testing capacity,” the Institute for Disease Modeling’s staff wrote in a report summarizing its Oregon forecast. “It will not be possible to relax social distancing measures and avoid an epidemic rebound without significantly increased testing.”

Testing has lagged in Oregon and the nation. Some Oregonians have waited nearly two weeks to get test results. Though testing has begun slowly expanding in Oregon, it is still so limited that the state discourages doctors from testing people who are asymptomatic, or have only mild symptoms.

If Oregon lifted social distancing measures right now, the institute estimates the state would see 15,000 coronavirus cases by May 8 – and as many as 26,000. Hospitals would need 850 regular beds and 250 intensive care beds.

Brown has canceled school through April 28 and has said she expects social distancing measures to be in place for an indefinite period.

Sidelinger said it was too soon to say when Oregon may be able to end its unprecedented statewide shutdown. “This is a long-term issue to keep social distancing in place,” he said.

— Rob Davis

rdavis@oregonian.com

503.294.7657; @robwdavis

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