Accurate SARS-CoV-2 diagnosis is essential to guide prevention and control of COVID-19. Here we examine SARS-CoV-2 molecular-based test performance characteristics and summarize case-level data related to COVID-19 diagnosis. From January 11 through April 22, 2020, Public Health Ontario conducted SARS-CoV-2 testing of 86,942 specimens collected from 80,354 individuals, primarily using real-time reverse-transcription polymerase chain reaction (rRT-PCR) methods. We analyzed test results across specimen types and for individuals with multiple same-day and multi-day collected specimens. Nasopharyngeal compared to throat swabs had a higher positivity (8.8% vs. 4.8%) and an adjusted estimate 2.9 C t lower (SE = 0.5, p <0.001). Same-day specimens showed high concordance (98.8%), and the median C t of multi-day specimens increased over time. Symptomatic cases had rRT-PCR results with an adjusted estimate 3.0 C t (SE = 0.5, p <0.001) lower than asymptomatic/pre-symptomatic cases. Overall test sensitivity was 84.6%, with a negative predictive value of 95.5%. Molecular testing is the mainstay of SARS-CoV-2 diagnosis and testing protocols will continue to be dynamic and iteratively modified as more is learned about this emerging pathogen.
【초록키워드】 COVID-19, SARS-CoV-2, Diagnosis, Predictive value, polymerase chain reaction, sensitivity, rRT-PCR, Concordance, Characteristics, pathogen, SARS-CoV-2 testing, nasopharyngeal, COVID-19 diagnosis, specimens, Prevention and control, Negative predictive value, Chain Reaction, throat swabs, individual, specimen, symptomatic cases, throat swab, testing protocols, Public, polymerase chain, analyzed, collected, conducted, adjusted, individuals, testing protocol, the median, 【제목키워드】 global pandemic, Stage, initial, diagnosis of COVID-19,