Viviana Gourley, a medical assistant at Salud Medical Center, adjusts one of her two masks at the center's COVID-19 testing area in Woodburn on Wednesday, April 29. (Amanda Loman/Salem Reporter)

The Salem area is still seeing a steady increase in people newly diagnosed with Covid, but health workers have been able to trace most cases to a known source, something many of Oregon’s larger counties have struggled to do in recent weeks.

It’s one bright spot amid a statewide escalation in cases that Gov. Kate Brown called “alarming” over the weekend. She warned Wednesday she may tighten restrictions on businesses again if numbers don’t improve and implored Oregonians to wear masks in indoor public places.

Marion County now has 1,544 residents who have tested positive for or are presumed to have the virus, an increase of 166 cases over the past week. Forty-seven of those people, about 3% of the total, have died from the virus. Polk County to date has 149 cases of the virus and 12 deaths.

(Graphic by Rachel Alexander/Salem Reporter)

But community spread of the virus in the Salem area remains lower. Last week, Oregon Health Authority reported just 16% of Marion County cases could not be traced to someone else known to have Covid. That’s far lower than a statewide rate of 33%. State health officials have said that number should remain under 30% in each county.

The daily number of people in Marion County testing positive for or presumed to have the virus has fluctuated over the past week from a low of six to a high of 44, largely mirroring fluctuations in the number of tests reported back.

Overall, the percentage of county residents whose tests come back positive has stayed relatively constant, between 6 and 7% weekly, according to a Salem Reporter analysis of the county’s published data. That’s a key public health metric because it helps show whether an increase in reported cases is because more people are being tested or because the virus is spreading more widely.

Marion County still has a higher percentage of positive tests than Oregon’s average, suggesting the virus is more widespread here.

As the virus has become more widespread, health workers are seeing the average age of people testing positive go down, said Jenna Wyatt, county health department spokeswoman. That’s been true across the U.S. and suggests younger people with very mild symptoms may be driving the spread of the virus.

She said recent case increases have been mostly linked to outbreaks in workplaces, long-term care facilities and spread between people in the same household.

(Graphic by Rachel Alexander/Salem Reporter)

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