A massive wave of federal testing supplies may provide Oregon its best chance to drive down coronavirus spread low enough to eventually reopen schools to on-site learning, according to the state’s top health administrator.
The federal government has pledged to give Oregon 60,000 to 80,000 tests each week through the end of the year, presenting state officials with a limited window to identify more infections that sow new cases.
State officials say there’s no way those testing supplies would enable serial testing at schools and a full-scale, immediate reopening. But they hope expanding testing and eligibility will allow them to identify and quarantine more spreaders of the virus, eventually curbing new cases to meet school reopening metrics set by Gov. Kate Brown.
“We really think focusing these tests on driving down the prevalence rate will get us to where we can open schools for the long haul, and do it safely,” said Patrick Allen, director of the Oregon Health Authority.
But that optimism will be challenged on several fronts. Public health officials across the country worry spread could increase during the fall, as happened during the 1918 flu pandemic. Oregon lacks new screening sites to more easily access tests. And the tests have a shelf-life of only about five months, leaving the state unable to stockpile supplies.
“It is going to be a big challenge,” Allen acknowledged.
As The Oregonian/OregonLive first reported last week, state officials learned only recently they’d receive an influx of tests as part of a commitment from the Trump administration to provide 100 million tests across the country.
Oregon’s governor called the new supply of tests from the federal government “huge” during a news conference Tuesday. But she also tried to set expectations.
“We absolutely cannot test our way out of this pandemic,” Brown said.
State officials say their first step will be expanding testing criteria. The state this week will begin recommending testing for anyone exposed through close contact to a confirmed or suspected coronavirus infection, even if the person lacks symptoms.
That change will ensure Oregon’s testing guidance matches the Centers for Disease Control and Prevention, which established more aggressive testing recommendations.
It’s unclear how many more Oregonians will be tested as a direct result of the expanded criteria. But state officials said each person who is infected has, on average, 10 close contacts who would now be eligible for testing.
“I think it remains to be seen how many people will agree to be tested,” said Dr. Melissa Sutton, the state’s medical director for respiratory viral pathogens.
Oregon has relatively few coronavirus cases and deaths compared to other states. Oregon also has one of the nation’s lowest per capita testing rates, with only about 30,000 tests completed each week.
Allen said he’d like to see the state use at least half of the federal government’s allotment on top of the state’s existing benchmark, meaning at least 60,000 Oregonians should be tested weekly during the fall.
“If we’re not using more than half, I’m going to be asking the question of, ‘What do we need to do to get more of the testing deployed, or, in fact, are we deploying all of it that we can?’” Allen said. “But that will be my threshold for wondering, ‘What’s up?’”
Kristen Donheffner, the agency’s testing strategy manager, said testing 60,000 Oregonians a week is doable.
“I think that is definitely our expectation,” she said, adding that it will take a few weeks to hit the target.
State officials would also like to expand the locations where tests will be available but that poses challenges. For now, the state expects to distribute tests to county health departments, tribes, federally qualified health centers, rural hospitals and existing mobile sites.
“Our goal is not to have these tests collecting dust,” Donheffner said. “We want them used.”
The new technology, called the Abbott BinaxNOW, is an antigen test that provides results within 15 minutes. In many ways it’s similar to the diagnostic tests most people are familiar with – samples are collected by a medical professional using a nasal swab.
But an antigen test detects proteins on the surface of a virus rather than detecting the underlying genetic material, which is how molecular PCR tests work.
Antigen tests, while inexpensive and easy to administer, aren’t always as accurate. State officials worry that the tests may produce a higher rate of false negatives, giving infected people the wrong impression they don’t have the virus.
“It’s really important to note that testing is not infallible,” Sutton, the director for respiratory viral pathogens, said.
“I want all Oregonians to know that false negative test results are not uncommon,” she added. “That means if you get a negative test result, you can’t stop wearing your mask; you can’t stand closer to your friends; you can’t attend gatherings or a wedding; or visit a vulnerable family member.”
The new tests come at a key time for Oregon. The average daily case count for the past week is on the upswing, at nearly 300. State modeling suggests the number will increase this month.
Allen, the health authority director, said the state is reviewing its school reopening criteria and may make changes in the coming weeks.
He said the state is likely to keep requirements that a county must have fewer than 10 cases per 100,000 residents in recent weeks to fully reopen to on-site learning, or 30 cases per 100,000 residents to reopen kindergarten through third grade.
But he said officials may nix a statewide requirement that would block full reopenings if the state’s weekly test positivity rate is above 5%.
“What we’re really trying to avoid is this whipsawing back and forth between open and closed,” he said of reopening schools. “Because as tough as distance learning is, I think that would be even worse on kids and families and schools.”
-- Brad Schmidt; bschmidt@oregonian.com; 503-294-7628; @_brad_schmidt