New Projections Show Social Distancing Is Helping Slow Coronavirus Spread In Oregon

By Meerah Powell (OPB)
Portland, Ore. April 11, 2020 9 p.m.

New projections released Saturday by the Oregon Health Authority estimate there are currently about 7,000 cases of novel coronavirus in Oregon, contrary to the about 1,400 cases that have been diagnosed.

As of Saturday, there have been 1,447 diagnosed coronavirus cases in the state out of more than 28,600 people tested, according to the Oregon Health Authority.


“It is, to me, believable that there are that many more cases out in the community that we haven’t diagnosed,” Dr. Dean Sidelinger, state epidemiologist with the OHA, said of the 7,000 cases figure. “With a virus that spreads very easily, causing mild or even no symptoms in many people, we do see pretty aggressive spread, so those projections aren’t very surprising.”

The projections, made by the Institute for Disease Modeling in Bellevue, Washington, estimate that Oregon’s interventions, such as Gov. Kate Brown’s stay-home order and other social distancing measures, have significantly reduced the burden on local health care systems.

If no social distancing measures were taking place in Oregon, coronavirus cases would have doubled every five to seven days, the report states, resulting in about 25,000 current cases in the state rather than the estimated 7,000.

Although social distancing measures have significantly decreased the number of cases Oregon could have seen, the state must maintain the current “aggressive interventions” in order to continue decreasing active cases, the report states.

“These models give us an idea of where we could be in a little over a month, and it shows that these aggressive actions need to continue in order to keep those cases down,” Sidelinger said.

If Oregon were to return to “moderate interventions,” such as bans on gatherings of more than 250 people, instead of sticking with the “stay home, save lives” recommendations, the state could see anywhere from more than 40,000 to almost 80,000 total coronavirus cases by May 18.

The state would also see anywhere from just fewer than 15,000 to more than 20,000 people actively sick with coronavirus by mid-May.


“That’s what we worry about even more than total infections, that number of people who are sick at any one time,” Sidelinger said. “Those are the people who are potentially infecting others and also potentially seeking care in our health care system and needing care at the same time.”

Returning to moderate interventions could also result in anywhere from a total of about 400 to more than 600 deaths by May 18, the report states.

With the continued stay-home order in place, Oregon will likely see anywhere from 10,000 to 20,000 total cases by May 18, including a slowly declining number of actively infectious people and fewer than 200 total deaths.

But, without increasing the number of tests given, there will not be a way to accurately know how many people in the state are infected with the virus, and therefore no way to safely relax social distancing guidelines, the report said.

Sidelinger agrees.

“We know that we would want to have more testing and testing results available fairly quickly so that we can test more people, even those folks with mild symptoms, to let them know whether they don’t or do have COVID-19,” he said.

Sidelinger said he hopes for testing to continue to increase to get the state “where we need to be.”

“This isn’t a switch that we turned on all at once,” Sidelinger said of social distancing measures in the state. “It’s likely as they’re turned off, they’re turned off in a staggered way as well and that some may stay in place for much longer periods of time until that vaccine or really effective treatment is available.”

Even though the projections show a relatively flat level of cases by mid-May, Sidelinger said, “These estimations are not a prediction of the future.”

In the meantime, he encourages Oregonians to continue social distancing measures.