UPDATE (11:30 a.m. PT, Monday, June 15) — The state of Oregon saw a significant uptick in COVID-19 cases over the past weekend. The bump comes just days after Gov. Kate Brown approved 29 of the state’s 36 counties to further relax business closures and social distancing measures under Phase 2 of reopening.

State public health officials have not shied away from predictions that the number of people infected with novel coronavirus would go up once people started to interact in public spaces again.

Still, the case bump that counties have experienced has caught some off guard.

“I think many of us felt that it was never really going to hit us here. So waking up yesterday and hearing the news about 124 cases at Pacific Seafood was a shock to many of us,” said Lincoln County health officer Dr. David Long during a press conference Monday.

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Lincoln County has been the hardest hit in per capita caseload increases during this second wave of infections. Between the first signs of a coronavirus outbreak earlier this year and May 15 (when most Oregon counties entered the first phase of reopening), Lincoln County registered seven positive cases. As of Tuesday, the county had 165 cases.

Other counties have also seen rises in cases since reopening. Jefferson, Wasco and Hood River counties have seen their numbers more than double. Counties like Deschutes, Umatilla, Jackson, Yamhill and Lane have all seen steady increases as well.

As of Tuesday, all of these counties, except Lincoln and Hood River, have now been approved by the state to enter Phase 2 of reopening.

Cases in the three Portland metro counties are also on the rise. Multnomah County is still under full stay-home restrictions that began statewide in late March.

Allowing counties to reopen even as COVID-19 cases are on the rise may seem counterintuitive, but experts warn against giving too much credence to case numbers alone.

“I think it’s going to be more a holistic picture,” said Dr. Paul Cieslak, a communicable disease specialist with the Oregon Health Authority.

Warning signs 

The decision to reopen lies with the governor’s office, but Brown and her staff are acting on the advice of the Oregon Health Authority. OHA makes recommendations based on six health indicators. Each tells us something a little different about the virus’ spread and the state’s ability to respond.

  • The percent of tests that come back positive
  • The capacity of each county to identify others who have come in contact with people who test positive
  • COVID-19 hospitalizations
  • Number of emergency room visits by people with COVID-like symptoms
  • Ratio of cases that can be traced back to a known transmission source to those that can’t
  • Number of new cases

Aside from the number of people who die from COVID-19, the number of new cases that surface each day is perhaps the most talked-about statistic of the pandemic. But it’s not as straightforward as it might appear.

Most cases in Oregon are confirmed through testing. Given that so many coronavirus infections are asymptomatic (OHA estimates about four unknown cases for every known infection), who is tested and how much testing is done makes a big difference. The larger the net that’s cast, the more people that will come back with positive test results. Similarly, if you identify a new case at a particular worksite, and test everyone else that works there, you’re likely going to find more cases than if you tested more generally in the population.

On Sunday, Oregon reported 146 new cases of COVID-19, the largest single-day total since the pandemic began.

“As we look into it, it does appear that a lot of the increase is related to increased testing around a handful of outbreaks that we’ve had,” Cieslak said.

The outbreak at Pacific Seafood in Newport accounted for a large proportion of the cases reported statewide over the weekend. After identifying a small number of COVID-19 cases at the facility, the entire staff of 376 was tested. Results for one-third of the employees were positive.

Another factor to consider when looking at reports of new cases is what communities are affected. Adding 50 cases in a place like Hood River County, which has a small population, has a proportionally greater significance than adding those same cases in the Portland metro area. Looking at how many cases per thousand people can help give those numbers context.

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OHA’s Cieslak recommends looking beyond the daily count of new cases to gauge the prevalence of the coronavirus.

“A more stable thing to look at is going to be hospitalizations because they’re less subject to variances in physician testing,” he said.

The number of cases in Hood River County has more than tripled since June 1, but Hood River public health officer Dr. Christopher Van Tilburg says he is focused on another metric: testing positivity rate.

“We’re doing a massive amount of testing. … We’re testing asymptomatic people, which we’ve never done before … so we’re going to have more positives,” he said.

Looking at the percent of tests that come back positive is a good check on whether enough people are being tested. But it also gives a clue if more testing is the reason for an increase in cases and how you compare to others.

“We would like to be under the Oregon average,” Van Tilburg said.

Hood River County’s overall test positivity rate was below the state average until last weekend.

Tracing and tracking

When counties were first applying to enter Phase 1 of reopening, contact tracing capacity was a major criterion. Finding people in the community that have come in contact with individuals with COVID-19 and urging them to self-quarantine are pillars of how public health officials in the U.S. control the spread of communicable disease. The state set contact tracer requirements based on population and the ability for county health offices to initiate contact tracing for 95% of new cases within 24 hours of discovery.

Statewide, for the first couple weeks after reopening, Oregon was largely able to meet this goal. All but one county were in compliance. But responding to a bump in new cases can be challenging and some counties are feeling the strain.

“Right now we’ve got plenty of hospital capacity, we’ve got ICU beds, ventilators, we’ve got adequate PPE and staff. If we’re short of anything it’s the contact tracers. That’s because when we get 124 cases all at one time, it overwhelms the system,” said Lincoln County’s Long.

Failing in contact tracing means increasing the risk of broader community spread. One known case could rapidly become many more as community members who have unknowingly been infected continue to interact with others.

Contact tracing can also give public health officials clues about how a disease is spreading through the community. OHA is looking at whether those cases can be traced back to a known source — say an outbreak at a particular workplace — or if the spread is more sporadic and the source cannot be identified.

This was a concern in the very early stages of the pandemic in the Pacific Northwest. When cases could no longer be directly linked to people who had traveled abroad in outbreak areas, epidemiologists knew they had a much more serious problem on their hands.

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State health officials want to be able to trace at least 70% of new cases to a known source.

“You can shut it down a lot faster. Say I’ve got seven cases and they all came from Nursing Home A, my contact tracing becomes a whole lot easier,” said Jackilen Shannon, a professor at the OHSU-PSU School of Public Health. “If I’ve got seven cases and they’re throughout the city … now I’ve got seven different groups of people I’m doing these concentric circles of tracing around, that can be a lot more challenging.”

In the weeks leading up to reopening on May 15, Oregon was starting to meet this metric with regularity. But as people have started to move around in the community more, the percent of cases that can’t be linked to a known source started to increase.

Reaction time

Sitting to the left — and appropriately socially distanced — from Gov. Kate Brown as she announced the start of Phase 2 of reopening, state epidemiologist Dr. Dean Sidelinger acted as the voice of temperance.

“Reopening is not an on/off switch,” he said. “If we begin to see a looming danger, such as widespread cases that have no epidemiological links to another case and no link to an outbreak, if we see increased positive tests and other warning signs, then we may need to consider dialing back our permitted activities in that county or in that part of the state.”

It’s beginning to become clear that there are several counties that won’t meet the standards established by the OHA. But health officials are still not ready to draw conclusions from one bad weekend.

“It’s hard to say anything definitive about a few days’ worth of data. We’re really going to have to watch the trends and draw conclusions with the benefit of at least a little bit of hindsight,” OHA’s Cieslak said.

The fact that health officials feel they have enough leeway to pause for a breath and watch for trends to develop is an indicator in and of itself. It signals how much has changed since the pandemic began.

“A few months ago, the scary thing was we just didn’t know what was going to happen,” said OHSU’s Shannon.

Shannon recalls there were so few answers to the many very basic questions about the coronavirus. The alarming calculations about how quickly Oregon COVID-19 cases would overwhelm hospital capacity drove difficult and quick decisions from health care providers and policymakers.

But now, facing a potential second wave of COVID-19 cases, public health officials and health researchers are trying to get out in front of outbreaks.

“Ideally if we’re monitoring proactively,” Shannon said, “we’ll give ourselves a little more time, and the shutdown doesn’t have to be so severe.”