Performance Test 9.0 Evaluation Version Professional First Collected

Statistical analyses were performed using SAS (version 9.4; SAS Institute). Cycle threshold (Ct) values from real-time RT-PCR were compared using a Mann-Whitney U Test; 95 confidence intervals (CIs) were calculated using the exact binomial method.

Stevens 1; Kristen Knipe, MS 1; Justine Pompey, PhD 1; Christine Atherstone, PhD 1,3; David P.

Shewmaker, PhD 1; Magdalena Medrzycki, PhD 1; Phili Wong, MS 1; Shilpi Jain, PhD 1; Alexandra Tejada-Strop, MS 1; Shannon Rogers, MS 1; Brian Emery 1; Houping Wang, PhD 1; Marla Petway, MPH 1; Caitlin Bohannon, PhD 1; Jennifer M.

Folster, PhD 1; Adam MacNeil, PhD 1; Reynolds Salerno, PhD 1; Wendi Kuhnert-Tallman, PhD 1; Jacqueline E.

Kirking, MD 1; Khalilullah Sheiban, MD 4; Julie Kudrna, MPA 4; Theresa Cullen, MD 4; Kenneth K.

Sensitivity was higher for culture-positive specimens (92.6 and 78.6 for those from symptomatic and asymptomatic persons, respectively); however, some antigen test-negative specimens had culturable virus.

Antigen tests can be an important tool in an overall community testing strategy to reduce transmission.

Rapid antigen tests have received Food and Drug Administration (FDA) Emergency Use Authorization (EUA) for use in symptomatic persons ( 2 ), but data are lacking on test performance in asymptomatic persons to inform expanded screening testing to rapidly identify and isolate infected persons ( 3 ).

To evaluate the performance of the BinaxNOW rapid antigen test, it was used along with real-time reverse transcriptionpolymerase chain reaction (RT-PCR) testing to analyze 3,419 paired specimens collected from persons aged 10 years at two community testing sites in Pima County, Arizona, during November 317, 2020.

Viral culture was performed on 274 of 303 residual real-time RT-PCR specimens with positive results by either test (29 were not available for culture).

Compared with real-time RT-PCR testing, the BinaxNOW antigen test had a sensitivity of 64.2 for specimens from symptomatic persons and 35.8 for specimens from asymptomatic persons, with near 100 specificity in specimens from both groups.

Virus was cultured from 96 of 274 (35.0) specimens, including 85 (57.8) of 147 with concordant antigen and real-time RT-PCR positive results, 11 (8.9) of 124 with false-negative antigen test results, and none of three with false-positive antigen test results.

Among specimens positive for viral culture, sensitivity was 92.6 for symptomatic and 78.6 for asymptomatic individuals.

When the pretest probability for receiving positive test results for SARS-CoV-2 is elevated (e.g., in symptomatic persons or in persons with a known COVID-19 exposure), a negative antigen test result should be confirmed by NAAT ( 1 ).

Despite a lower sensitivity to detect infection, rapid antigen tests can be an important tool for screening because of their quick turnaround time, lower costs and resource needs, high specificity, and high positive predictive value (PPV) in settings of high pretest probability.

The faster turnaround time of the antigen test can help limit transmission by more rapidly identifying infectious persons for isolation, particularly when used as a component of serial testing strategies.

A questionnaire capturing demographic information and current and past14-day symptoms was administered to all participants.

Performance Test 9.0 Evaluation Version Professional First Collected

At both sites, a health care professional first collected a bilateral anterior nasal swab, using a swab provided in the BinaxNOW kit, immediately followed by a bilateral nasopharyngeal (NP) swab for real-time RT-PCR testing.

Anterior nasal swabs were immediately tested on-site using the BinaxNOW antigen test according to the manufacturers instructions ( 4 ).

NP swabs were stored in phosphate buffered saline at 39F (4C) and analyzed within 2448 hours by real-time RT-PCR using either the CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel for detection of SARS-CoV-2 ( 5 ) (2,582 swabs) or the Fosun COVID-19 RT-PCR Detection Kit ( 6 ) (837 swabs).

Viral culture, was attempted on 274 of 303 residual real-time RT-PCR specimens if either the real-time RT-PCR or BinaxNOW antigen test result was positive (the remaining 29 were not available for viral culture).

Results from real-time RT-PCR and the BinaxNOW antigen test were compared to evaluate sensitivity, specificity, negative predictive value (NPV), and PPV.

Statistical analyses were performed using SAS (version 9.4; SAS Institute).

Cycle threshold (Ct) values from real-time RT-PCR were compared using a Mann-Whitney U Test; 95 confidence intervals (CIs) were calculated using the exact binomial method.