Notes from the Field: Seroprevalence Estimates of SARS-CoV-2 Infection in Convenience Sample — Oregon May 11–June 15 2020

摘要

The first known case of coronavirus disease 2019 (COVID-19) in Oregon was diagnosed on February 28, 2020. Through May 31, a total of 4,243 COVID-19 cases in Oregon were confirmed by nucleic acid testing for SARS-CoV-2, the virus that causes COVID-19, yielding a cumulative COVID-19 incidence of approximately 0.1%. Because this rate does not account for persons who were infected but did not seek testing (e.g., those with asymptomatic or mildly symptomatic infections), persons who chose not to be tested, or persons unable to access testing, the rate is believed to be lower than the true cumulative COVID-19 incidence in the state. A population-based seroprevalence survey can provide estimates of the cumulative incidence of infection more accurately than does nucleic acid testing by identifying additional persons who have had previous infections with SARS-CoV-2 but were not reported as COVID-19 cases. Seroprevalence estimates from several states and geographic areas within the United States vary from 1.0% to 6.9 ( – ). No seroprevalence estimates for SARS-CoV-2 infection are yet available for Oregon.