tetano
Editor, Senior Moderator
Microbiol Spectr
. 2023 Apr 25;e0006423.
doi: 10.1128/spectrum.00064-23. Online ahead of print.
COVID-19 Antigen Results Correlate with the Quantity of Replication-Competent SARS-CoV-2 in a Cross-Sectional Study of Ambulatory Adults during the Delta Wave
Yuan-Po Tu[SUP] 1 [/SUP], Christopher Green[SUP] 2 [/SUP], Linhui Hao[SUP] 3 [/SUP], Alexander L Greninger[SUP] 4 [/SUP], Jennifer F Morton[SUP] 5 [/SUP], Heather A Sights[SUP] 1 [/SUP], Michael Gale Jr[SUP] 3 [/SUP], Paul K Drain[SUP] 5 [/SUP]
Affiliations
Abstract
Appropriate interpretation of various diagnostic tests for COVID-19 is critical, yet the association among rapid antigen tests, reverse transcription (RT)-PCR, and viral culture has not been fully defined. To determine whether rapid antigen testing correlates with the presence and quantity of replication-competent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in ambulatory adults, 626 adult participants were enrolled in a cross-sectional diagnostic study. Each participant had two anterior nasal swabs obtained for rapid antigen and RT-PCR testing and SARS-CoV-2 viral culture. The primary outcomes were the presence and quantification of SARS-CoV-2 growth in VeroE6-ACE2-TMPRSS2 cells in asymptomatic and symptomatic ambulatory adults. In this cross-sectional study of 626 adult outpatients, the sensitivity of a single positive antigen test to identify replication-competent SARS-CoV-2 was 63.6% in asymptomatic and 91.0% in symptomatic participants. Viral culture titers were the highest at the onset of symptoms and rapidly declined by 7 days after symptom onset. The positive agreement of the rapid antigen test with RT-PCR at a cycle threshold C[SUB]T[/SUB] less than 30 was 66.7% in asymptomatic and 90.7% in symptomatic participants. Among symptomatic participants a with a C[SUB]T[/SUB] less than 30, a single antigen test had a positive agreement of 90.7% (95% confidence interval [CI], 84.8% to 94.8%). There was 100% negative agreement as all 425 RT-PCR-negative participants had a negative antigen test. A positive antigen test in symptomatic adults with COVID-19 has a strong correlation with replication-competent SARS-CoV-2. Rapid antigen test results may be a suitable proxy for infectiousness. IMPORTANCE Do rapid antigen test results correlate with replication-competent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (i.e., infectious) virus? In this cross-sectional diagnostic study of 626 adults, the sensitivity of the antigen test to identify replication-competent SARS-CoV-2 was 63.6% in asymptomatic and 91.0% in symptomatic participants. Viral culture titers were the highest at the onset of symptoms and rapidly declined by 7 days after symptom onset. The positive agreement of the rapid antigen test with reverse transcription (RT)-PCR at a C[SUB]T[/SUB] of less than 30 was 66.7% in asymptomatic participants and 90.7% in symptomatic participants. A positive antigen test may be an appropriate surrogate for identifying replication-competent virus in symptomatic individuals with COVID-19.
Keywords: BinaxNOW; COVID-19; COVID-19 antigen; SARS-CoV-2; SARS-CoV-2 viral cultures; replication-competent.
. 2023 Apr 25;e0006423.
doi: 10.1128/spectrum.00064-23. Online ahead of print.
COVID-19 Antigen Results Correlate with the Quantity of Replication-Competent SARS-CoV-2 in a Cross-Sectional Study of Ambulatory Adults during the Delta Wave
Yuan-Po Tu[SUP] 1 [/SUP], Christopher Green[SUP] 2 [/SUP], Linhui Hao[SUP] 3 [/SUP], Alexander L Greninger[SUP] 4 [/SUP], Jennifer F Morton[SUP] 5 [/SUP], Heather A Sights[SUP] 1 [/SUP], Michael Gale Jr[SUP] 3 [/SUP], Paul K Drain[SUP] 5 [/SUP]
Affiliations
- PMID: 37097146
- DOI: 10.1128/spectrum.00064-23
Abstract
Appropriate interpretation of various diagnostic tests for COVID-19 is critical, yet the association among rapid antigen tests, reverse transcription (RT)-PCR, and viral culture has not been fully defined. To determine whether rapid antigen testing correlates with the presence and quantity of replication-competent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in ambulatory adults, 626 adult participants were enrolled in a cross-sectional diagnostic study. Each participant had two anterior nasal swabs obtained for rapid antigen and RT-PCR testing and SARS-CoV-2 viral culture. The primary outcomes were the presence and quantification of SARS-CoV-2 growth in VeroE6-ACE2-TMPRSS2 cells in asymptomatic and symptomatic ambulatory adults. In this cross-sectional study of 626 adult outpatients, the sensitivity of a single positive antigen test to identify replication-competent SARS-CoV-2 was 63.6% in asymptomatic and 91.0% in symptomatic participants. Viral culture titers were the highest at the onset of symptoms and rapidly declined by 7 days after symptom onset. The positive agreement of the rapid antigen test with RT-PCR at a cycle threshold C[SUB]T[/SUB] less than 30 was 66.7% in asymptomatic and 90.7% in symptomatic participants. Among symptomatic participants a with a C[SUB]T[/SUB] less than 30, a single antigen test had a positive agreement of 90.7% (95% confidence interval [CI], 84.8% to 94.8%). There was 100% negative agreement as all 425 RT-PCR-negative participants had a negative antigen test. A positive antigen test in symptomatic adults with COVID-19 has a strong correlation with replication-competent SARS-CoV-2. Rapid antigen test results may be a suitable proxy for infectiousness. IMPORTANCE Do rapid antigen test results correlate with replication-competent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (i.e., infectious) virus? In this cross-sectional diagnostic study of 626 adults, the sensitivity of the antigen test to identify replication-competent SARS-CoV-2 was 63.6% in asymptomatic and 91.0% in symptomatic participants. Viral culture titers were the highest at the onset of symptoms and rapidly declined by 7 days after symptom onset. The positive agreement of the rapid antigen test with reverse transcription (RT)-PCR at a C[SUB]T[/SUB] of less than 30 was 66.7% in asymptomatic participants and 90.7% in symptomatic participants. A positive antigen test may be an appropriate surrogate for identifying replication-competent virus in symptomatic individuals with COVID-19.
Keywords: BinaxNOW; COVID-19; COVID-19 antigen; SARS-CoV-2; SARS-CoV-2 viral cultures; replication-competent.