PORTLAND, Ore – The Oregon Health Authority released a coronavirus study Friday showing that a “substantial” portion of Oregonians have had an undiagnosed and unreported case of COVID-19.
The study, commissioned by OHA epidemiologists, found that 1% of Oregonians who do not have COVID-19 had evidence of past viral infection in their blood.
Officials say this is 10 times higher than the reported level of infections found through conventional testing.
“We suspected that a much larger segment of the Oregon population was exposed and infected with COVID-19 than traditional diagnostic test displays,” said Paul Cieslak, MD, an OHA study co-author and medical director for communicable diseases and immunizations. “But these results also show us that most Oregonians remain susceptible to this virus.”;
Nine of the 897 blood samples collected form 19 health care facilities across Oregon between May 11 and June 15 containing antibodies against the virus that causes COVID-19.
The rate of infection was shown to increase with age, with no antibodies found in the blood of pediatric patients 17 years of age and younger.
The first case of coronavirus from Oregon was diagnosed on February 28th. As of May 31, 4,243 people had tested positive, but these data do not account for people who did not request testing.
“Because most of us are still sensitive,” Cieslak said, “we must continue to practice physical distance and camouflage until we have vaccines, treatments or other effective means to alleviate illness.”
Antibodies do not show up in your blood until two or three weeks after exposure to the virus, Cieslak said. He added at this time experts are not sure if antibodies provide protection against COVID-19.
For more information on antibody testing, visit the CDC website.