We assessed the relationship between antigen and reverse transcription PCR (RT-PCR) test positivity and successful virus isolation. We found that antigen test results were more predictive of virus recovery than RT-PCR results. However, virus was isolated from some antigen-negative and RT-PCR‒positive paired specimens, providing support for the Centers for Disease Control and Prevention antigen testing algorithm.
Keywords: COVID-19; SARS-CoV-2; coronavirus disease; coronaviruses; cycle threshold; rapid antigen test; respiratory infections; reverse transcription PCR; severe acute respiratory syndrome coronavirus 2; viral cultures; viruses; zoonoses.