Austin Griffith, a medic with Woodburn Ambulance Service, administers a Covid test during a free drive-through testing clinic on Tuesday, Aug. 25. (Amanda Loman/Salem Reporter)

Health officials in Marion and Polk counties know that Covid cases are rising but often don't know where people are getting sick.

With “Covid fatigue” setting in after a year of pandemic restrictions on daily life, health officials say young adults who have yet to be vaccinated against the virus are driving the recent increase in cases that have resulted in a new round of stringent measures being placed on the counties. 

But public health workers are increasingly unable to identify where someone contracted Covid. That’s true statewide as well, frustrating efforts to understand where the virus is spreading. 

In Marion County, health workers were able to identify a source of infection for just 30% of people who tested positive for Covid the week of April 18, the most recent week Oregon Health Authority data was available. Polk County identified a source for about half, and Oregon as a whole for one-third. The state has set a target of 70%.

Health officials in both counties said social gatherings remain a significant driver of new cases, and people 40 and younger account for a larger share of new cases.

“We're hearing about more small and large social gatherings, and people are generally eager to get back to pre-covid activities,” said Jenna Wyatt, spokeswoman for the Marion County Department of Health and Human Services, in an email. “Many people in this age group also just recently became eligible for vaccination. We are hopeful that as more people are able to get the vaccine, case counts will again begin to decline.” 

Wyatt said Marion County is operating in “surge” mode for contact tracing, meaning a health worker will attempt to contact someone once after they test positive for Covid. If they are unable to reach the person, the health department sends them a letter with instructions about quarantining, but doesn’t follow up with additional calls.

She said the department has also lost some temporary contract tracer positions to permanent public health jobs, reducing the number of people working on Covid surveillance, though she did not give an exact number.

In Polk County, contact tracing has been frustrated by people health workers either can’t reach or who are unwilling to be interviewed, said public health administrator Jacqui Umstead.

Umstead said the county couldn’t identify a source of infection for  46 people who tested positive for Covid the week of April 18. Of those, 16 were people who couldn’t be contacted or refused to answer questions, she said.

The Oregon Health Authority publicly reports weekly Covid outbreaks in workplaces that include five or more cases in employers with 30 or more workers, as well as in long-term care facilities, schools and child care settings. The number of such outbreaks and the new cases associated with them has declined in recent weeks even with more people diagnosed with Covid statewide.

Younger people are less likely to get seriously ill from Covid, but hospitalizations statewide and locally are also on the rise even as the average age of someone with Covid has shifted younger. Deaths related to the virus have declined in April, likely reflecting higher vaccination rates among older Oregonians who are most vulnerable.

State health officials have said more contagious variants of the virus have contributed to that trend, and the Oregon Health Authority believes the B.1.1.7 variant of the virus, first detected in the United Kingdom, is now the dominant strain in Oregon. That strain is more contagious.

Just 3% of all virus samples taken from patients are analyzed for variants, the Oregonian/OregonLive reported. Wyatt said without more specific local data it’s difficult to tell what role the variants play in rising hospitalizations in Marion County.

Salem Health had 61 people with Covid in the hospital as of April 29, spokeswoman Lisa Wood said, ranging in age from early 20s to late 90s.

Wood said the common denominator among those sick was clear: 59 of the 61 were unvaccinated.

“This illustrates the importance of being vaccinated, as studies show the vaccine retains effectiveness against the variants. Breakthrough cases have been seen but are in line with what would be expected in both the Pfizer and Moderna studies,” Wood said in a statement. “Breakthrough” cases refer to people who contract Covid more than two weeks after receiving their final vaccine dose. Such cases are very rare: as of April 8, the health authority had counted 168 breakthrough cases among the 700,000 Oregonians who were fully vaccinated against Covid.

From April 11 to April 24, Marion County recorded 1,041 new cases of Covid, up from 477 new cases during the prior two weeks. Polk County recorded 179 new cases, up from 159.

The local increase in new cases and the rising number of hospitalizations statewide led Gov. Kate Brown to order 15 counties back under “extreme risk” for Covid starting Friday. That designation comes with tighter restrictions, including an indoor dining ban. Marion and Polk are among them.

The restrictions will also reduce the numbers of people allowed inside gyms, churches and event venues. That decision drew outcry from local county commissioners, who said in a letter to the governor and in meetings this week that the state has shown no evidence the activities being restricted are the cause of new Covid cases.

“It’s absolutely ridiculous that we’re going into this and we’re only forcing businesses who are in fact not spreading this virus … to close,” said county commissioner Danielle Bethell in an April 28 meeting.

A spokesman for the governor defended the decision.

“COVID-19 spreads more quickly indoors, where there is less air circulation, which is why a number of indoor activities are curtailed in Extreme Risk, in addition to indoor dining. We also know that eating and drinking involves sitting for long periods of time indoors without wearing a mask, and often involves people meeting who do not live in the same household. That makes it a particularly risky activity when COVID-19 is so widespread in our communities,” spokesman Charles Boyle said in an email.

Contact reporter Rachel Alexander: [email protected] or 503-575-1241.

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