Performance of an Antigen-Based Test for Asymptomatic and Symptomatic #SARS-CoV-2 Testing at Two University Campuses — Wisconsin, September–October 2020 | MMWR
▻https://www.cdc.gov/mmwr/volumes/69/wr/mm695152a3.htm
Summary
What is already known about this topic?
Antigen tests for SARS-CoV-2 are inexpensive and can return results within 15 minutes, but test performance data in asymptomatic and symptomatic persons are limited.
What is added by this report?
Compared with real-time reverse transcription–polymerase chain reaction (RT-PCR) testing, the Sofia antigen test had a sensitivity of 80.0% and specificity of 98.9% among symptomatic persons; accuracy was lower (sensitivity 41.2% and specificity 98.4%) when used for screening of asymptomatic persons.
What are the implications for public health practice?
To account for reduced antigen test accuracy, confirmatory testing with a nucleic acid amplification test (e.g., RT-PCR) should be considered after negative antigen test results in symptomatic persons and positive antigen test results in asymptomatic persons.
Cependant,
Ct values for specimens with false-negative antigen results were significantly higher compared with antigen- and real-time RT-PCR-positive specimens (mean N1 Ct = 32.3 versus 23.7; p<0.01).
