Antigen-Based Testing but Not Real-Time Polymerase Chain Reaction Correlates With Severe Acute Respiratory Syndrome Coronavirus 2 Viral Culture

Pekosz, Andrew; Parvu, Valentin; Li, Maggie; Andrews, Jeffrey C; Manabe, Yukari C.; Kodsi, Salma; Gary, Devin S.; Roger-Dalbert, Celine; Leitch, Jeffry; Cooper, Charles K.

doi:10.1093/cid/ciaa1706

Cited by 248 publications

(253 citation statements)

References 24 publications

Supporting

Mentioning

222

Contrasting

Unclassified

Order By: Relevance

“…Although many caveats remain, the point in the course of the first week of symptoms at which AgPOCT results turn negative might thus indicate the time at which infectivity resolves. 29 The immediate availability of test results could enable novel public health concepts in which decisions to isolate or maintain isolation are based on infectivity testing rather than infection screening. On first patient contact, a positive AgPOCT result could also help to decide on immediate isolation measures by the identification of individuals who shed particularly large amounts of virus, which would be particularly useful in emergency departments.…”

Section: Discussionmentioning

confidence: 99%

Comparison of seven commercial SARS-CoV-2 rapid point-of-care antigen tests: a single-centre laboratory evaluation study

et al. 2021

View full text Add to dashboard Cite

Background Antigen point-of-care tests (AgPOCTs) can accelerate SARS-CoV-2 testing. As some AgPOCTs have become available, interest is growing in their utility and performance. Here we aimed to compare the analytical sensitivity and specificity of seven commercially available AgPOCT devices. Methods In a single-centre, laboratory evaluation study, we compared AgPOCT products from seven suppliers: the Abbott Panbio COVID-19 Ag Rapid Test, the RapiGEN BIOCREDIT COVID-19 Ag, the Healgen Coronavirus Ag Rapid Test Cassette (Swab), the Coris BioConcept COVID-19 Ag Respi-Strip, the R-Biopharm RIDA QUICK SARS-CoV-2 Antigen, the nal von minden NADAL COVID-19 Ag Test, and the Roche-SD Biosensor SARS-CoV Rapid Antigen Test. Tests were evaluated on recombinant SARS-CoV-2 nucleoprotein, cultured endemic and emerging coronaviruses, stored respiratory samples with known SARS-CoV-2 viral loads, stored samples from patients with respiratory pathogens other than SARS-CoV-2, and self-sampled swabs from healthy volunteers. We estimated analytical sensitivity in terms of approximate viral concentrations (quantified by real-time RT-PCR) that yielded positive AgPOCT results, and specificity in terms of propensity to generate false-positive results. Findings In 138 clinical samples with quantified SARS-CoV-2 viral load, the 95% limit of detection (concentration at which 95% of test results were positive) in six of seven AgPOCT products ranged between 2·07 × 10 6 and 2·86 × 10 7 copies per swab, with an outlier (RapiGEN) at 1·57 × 10 10 copies per swab. The assays showed no cross-reactivity towards cell culture or tissue culture supernatants containing any of the four endemic human coronaviruses (HCoV‑229E, HCoV‑NL63, HCoV‑OC43, or HCoV‑HKU1) or MERS-CoV, with the exception of the Healgen assay in one repeat test on HCoV-HKU1 supernatant. SARS-CoV was cross-detected by all assays. Cumulative specificities among stored clinical samples with non-SARS-CoV-2 infections (n=100) and self-samples from healthy volunteers (n=35; cumulative sample n=135) ranged between 98·5% (95% CI 94·2–99·7) and 100·0% (97·2–100·0) in five products, with two outliers at 94·8% (89·2–97·7; R-Biopharm) and 88·9% (82·1–93·4; Healgen). False-positive results did not appear to be associated with any specific respiratory pathogen. Interpretation The sensitivity range of most AgPOCTs overlaps with SARS-CoV-2 viral loads typically observed in the first week of symptoms, which marks the infectious period in most patients. The AgPOCTs with limit of detections that approximate virus concentrations at which patients are infectious might enable shortcuts in decision making in various areas of health care and public health. Funding EU's Horizon 2020 research and innovation programme, German Ministry of Research, German Federal Ministry for Economic Affairs and Energy...

show abstract

Section: Discussionmentioning

confidence: 99%

Comparison of seven commercial SARS-CoV-2 rapid point-of-care antigen tests: a single-centre laboratory evaluation study

et al. 2021

View full text Add to dashboard Cite

show abstract

“…9 Rapid antigen tests have higher limits of detection than PCR tests and higher sensitivity in testing when viral concentrations are higher. 10 For example, the Panbio rapid antigen test has an overall sensitivity of 73% in symptomatic patients compared with RT-PCR; however, it has a sensitivity of 97% compared with RT-PCR with Ct values less than 25. 11 In a study that compared results for a single paired Sofia SARS antigen fluorescent immunoassay and an RT-PCR test among asymptomatic university students at 2 diferent campuses in Wisconsin, the sensitivity of the rapid test was 41.2% and specificity 98.4%.…”

Section: Discussionmentioning

confidence: 99%

Rapid antigen screening of asymptomatic people as a public health tool to combat COVID-19

Schwartz

McGeer

Bogoch

2021

CMAJ

View full text Add to dashboard Cite

J urisdictions across Canada have been trying to combat a second wave of the coronavirus disease 2019 (COVID-19) pandemic without using all the available tools. Accumulating evidence has shown that people who are infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who are either presymptomatic (but subsequently develop symptoms) or paucisymptomatic (have mild symptoms that do not prompt a medical visit) are major contributors to transmission. However, current approaches of testing predominately symptomatic patients and relying on the results of expensive and slow laboratory-based testing for contact tracing have proven inadequate to control the spread of the disease, with associated economic and societal impacts. Frequent rapid antigen testing is a scalable public health tool that can efectively identify asymptomatic and paucisymptomatic people with SARS-CoV-2 infection and improve contact tracing and control of outbreaks. Why test people who have no symptoms of COVID-19? A 2020 study of transmission dynamics in Taiwan showed that the infectious period for COVID-19 starts 2-3 days before symptom onset and continues to about 5 days afer. 1 Modelling has estimated that more than 50% of SARS-CoV-2 transmissions occur during the presymptomatic period or during asymptomatic infection. 2,3 A study in which the authors reconstructed transmission in China up to April 2020 found that presymptomatic transmission accounted for a high proportion (40%-90%) of transmissions. 4 Furthermore, higher viral loads have been shown to be significantly associated with higher transmission risk irrespective of symptoms. 5 Even with ideal public health resources for testing and tracing, the strategy of testing only symptomatic cases will not identify many of the contacts before they transmit infection. A report from the Ofice of the Auditor General of Ontario indicated that the average time from specimen collection to the start of case and contact management was 4.25 days. 6 In this scenario, for patients who seek testing on their first day of symptoms, on KEY POINTS • People who are presymptomatic and paucisymptomatic are important contributors to the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). What rapid antigen tests are available and how should they be evaluated? Although many diferent devices are being produced, the Abbott Panbio lateral flow assay is the only device with Health Canada approval at the time of writing. Lateral flow assays detect a protein

show abstract

“…A patient with a positive Ag-RDT result within 5 days after symptom onset can be considered to have a SARS-CoV-2 infection, because these individuals are more likely to have high viral loads [11]. However, a negative result must be interpreted with caution due to reduced sensitivity with low viral load and a confirmation test (RT-PCR) is recommended [10].…”

Section: Introductionmentioning

confidence: 99%

Development and Evaluation of a new Swiss Made SARS-CoV-2 antigen-detecting rapid test

Ducrest

2021

Preprint

View full text Add to dashboard Cite

There is an urgent need in rapid diagnostic test (RDT) to detect antigen of SARS-CoV-2 to reduce the spread of COVID-19 outbreak. We have developed a rapid and simple point-of-care lateral flow immunoassay (LFIA) detecting nucleocapsid antigen of SARS-CoV-2 in 10 minutes. The aim of this study is to evaluate the diagnostic performance and analytical sensitivity of this RDT. RT-PCR positive nasopharyngeal swab samples (n=20) for SARS-CoV-2 and 40 negative control samples were studied. Analytical sensitivity was assessed using Gamma-irradiated SARS-CoV-2 and the limit of detection (LOD) was determined at 1.4 x 10^2 TCID50/ml. Overall, RDT diagnostic sensitivity was 90% (95% confidence interval [95%CI]: 67-98%) and specificity 98% (95% CI: 85-100%). The sensitivity was 100% (95% CI: 75-100%) when using only samples with a RT-PCR Cycle threshold lower than 30. This antigen RDT displays a high diagnostic accuracy for SARS‐CoV‐2 antigen detection in high COVID‐19 prevalence settings. Its use could be considered in the absence of routine RT-PCR facilities such in low-income countries.

show abstract

Antigen-Based Testing but Not Real-Time Polymerase Chain Reaction Correlates With Severe Acute Respiratory Syndrome Coronavirus 2 Viral Culture

Cited by 248 publications

References 24 publications

Comparison of seven commercial SARS-CoV-2 rapid point-of-care antigen tests: a single-centre laboratory evaluation study

Comparison of seven commercial SARS-CoV-2 rapid point-of-care antigen tests: a single-centre laboratory evaluation study

Rapid antigen screening of asymptomatic people as a public health tool to combat COVID-19

Development and Evaluation of a new Swiss Made SARS-CoV-2 antigen-detecting rapid test

Contact Info

Product

Resources

About