Abstract
Our study aim was to evaluate the performance of the automated Sysmex HISCL® severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen assay against reverse-transcription polymerase chain reaction (RT-PCR). We tested 277 remnant frozen nasopharyngeal swab samples, stored in universal transport medium (UTM), yielding a sensitivity of 94.9% against historical RT-PCR results with cycle threshold (C t ) < 30, and a sensitivity of 76.7% for C t < 35, and specificity of 100% (all C t values) confirming compatibility of UTM-diluted samples with the assay system. Thereafter, we prospectively collected 141 nasopharyngeal swab samples in UTM from healthcare workers and 1369 paired swabs (400 UTM; 969 dry) from individuals at a public health testing center, with the first swab (UTM) reserved for RT-PCR, yielding a positivity rate of 4.6%. HISCL assay performance using UTM swabs was superior to dry swabs, with a sensitivity of 100% (95% confidence interval [CI] 71.5%-100%) at C t < 30 versus 92.3% (95%CI 81.5%-97.9%), and a specificity of 99.3% (95% CI 98.1-99.89) against 83.3% (95%CI 80.7%-85.6%). We conclude that this antigen assay is suitable for high throughput facilities where the primary indication for testing is to rule out infection with low RT-PCR C t values (proxy for high viral loads) to curb viral spread.
Keywords: HISCL automated antigen assay; RT-PCR; SARS-CoV-2; method comparison; rapid testing; variants of concern.
【저자키워드】 SARS-CoV-2, variants of concern, RT-PCR, method comparison, HISCL automated antigen assay, rapid testing, 【초록키워드】 public health, coronavirus, Healthcare workers, Infection, variants of concern, severe acute respiratory syndrome Coronavirus, RT-PCR, viral spread, variants, healthcare worker, Antigen, Nasopharyngeal swab, polymerase chain reaction, sensitivity, specificity, cycle threshold, swabs, automated, Swab, Nasopharyngeal swab samples, Chain Reaction, transport medium, Transport, acute respiratory syndrome, 95%CI, 95% CI, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, 95% confidence interval, medium, individual, viral loads, compatibility, nasopharyngeal swab sample, Universal Transport Medium, polymerase chain, tested, collected, evaluate, UTM, yielding, 【제목키워드】 automated, SARS-CoV-2 antigen, subject, nasopharyngeal swab sample, symptomatic and asymptomatic,