Second round of testing shows significantly decreased prevalence

Team leaders of Oregon State University’s TRACE-COVID-19 study rally volunteers outside the Hatfield Marine Science Center on July 11 before they venture into Newport neighborhoods to collect samples door-to-door.

NEWPORT — Preliminary results of the most recent round of door-to-door sampling in Newport through Oregon State University’s TRACE-COVID-19 study indicate a prevalence of less than one-fifth that found during the first round of sampling.

Results of testing conducted in Newport on July 11 and 12 found an estimated prevalence of six in 1,000, compared to the 34 out of 1,000 prevalence indicated through testing in June. TRACE field teams visited homes in 30 Newport neighborhoods and received samples from 550 people. The number of positive results was not reported because it was lower than 10.

Ben Dalziel, assistant professor in the College of Science at OSU and co-director of TRACE, said, “This is good news, but the outbreak isn’t over. To keep things headed in the right direction, we urge residents and visitors alike to keep up the hard work — wear face masks, follow physical and social distance guidelines and abide by group size guidelines.”

Researchers also collected wastewater samples from 22 locations in Newport and from the wastewater treatment plant in late June and early July to analyze them for genetic evidence of SARS-CoV-2, the virus that causes COVID-19. Those samples provide an integrated picture for the whole city, and the results reinforce the findings of the random door-to-door sampling. They showed a steady increase in virus concentration from June 10 to June 19 — just before the first TRACE visit — then a steady decrease in virus concentrations from June 19 to July 10.

Javier Nieto, dean of OSU’s College of Public Health and Human Sciences and one of TRACE’s leaders, said there is still cause for caution. “While the prevalence of the virus is lower across much of Newport, there are still pockets of infection,” Nieto said. “These pockets can easily flare up and trigger a resurgence of the disease.”

Wastewater samples were also collected from Depoe Bay, Lincoln City, Siletz, Toledo and Yachats. The virus was detected at moderate levels in Depoe Bay on July 4 and in Toledo on June 30, July 1 and 8. Previous samples in those communities did not show traces of the virus, nor did samples taken after those dates, and neither community had levels of the virus as high as were detected in Newport’s wastewater. Wastewater samples from Lincoln City, Siletz and Yachats did not detect the virus.

In its weekly testing summary released on Monday, the Oregon Health Authority reported the first decline in the statewide positivity rate since the percent of positive tests began to rise in late May. Of the 38,179 test results reported the previous week, 4.8 percent were positive. That hopeful news came with a caveat — the report said several major manufacturers had informed the authority that testing supply allocation to labs in Oregon “may be reduced over the coming weeks due to the recent spike in positive COVID-19 cases nationally and increased demand for testing.”

The authority’s testing summary also said it had received widespread reports of long turnaround times from commercial laboratories, with some results “being reported up to two weeks following specimen collection.” During Monday’s Lincoln County Board of Commissioners meeting, Lincoln County Public Health Director Rebecca Austen named Quest as the laboratory behind local delays. Results from testing at Lakeview Senior Living in Lincoln City were not reported to the facility for more than two weeks after collection — 108 residents were tested on July 1, and a single positive result was reported to the facility on July 19.


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