RESUMO
ObjectiveTo assess the diagnostic accuracy of three rapid antigen tests (Ag-RDTs) for detecting SARS-CoV-2 infection in the general population. DesignCross-sectional study with follow-up using pseudonymised record linkage. SettingThree Dutch public health service COVID-19 test sites. ParticipantsConsecutively included individuals aged 16 years and older presenting for SARS-CoV-2 testing. Main outcome measuresSensitivity, specificity, positive and negative predictive values of BD-Veritortm System (Becton Dickinson), PanBio (Abbott), and SD-Biosensor (Roche Diagnostics), applying routinely used sampling methods (combined oropharyngeal and nasal [OP-N] or nasopharyngeal [NP] swab), with molecular testing as reference standard. For SD-Biosensor, the diagnostic accuracy with OP-N sampling was also assessed. A viral load cut-off ([≥]5.2 log10 SARS-CoV-2 E-gene copies/mL) served as a proxy of infectiousness. ResultsSARS-CoV-2 prevalence and overall sensitivities with 95% confidence intervals were 188/1441 (13.0%) and 129/188 (68.6% [61.5%-75.2%]) for BD-Veritor, 173/2056 (8.4%) and 119/173 (68.8% [61.3%-75.6%]) for PanBio, and 215/1769 (12.2%) and 160/215 (74.4% [68.0%-80.1%]) for SD-Biosensor with routine sampling, and 164/1689 (9.7%) and 123/164 (75.0% [67.7%-81.4%]) for SD-Biosensor with OP-N sampling. In those symptomatic or asymptomatic at sampling, sensitivities were 72.2%-83.4% and 54.0%-55.9%, respectively. With a viral load cut-off, sensitivities were 125/146 (85.6% [78.9%-90.9%]) for BD-Veritor, 108/121 (89.3% [82.3%-94.2%]) for PanBio, 160/182 (87.9% [82.3%-92.3%]) for SD-Biosensor with routine sampling, and 118/141 (83.7% [76.5%-89.4%]) with OP-N sampling. Specificities were >99%, and positive and negative predictive values >95%, for all tests in most analyses. 61.3% of false negative Ag-RDT participants returned for testing within 14 days (median of 3 days, interquartile range 3) of whom 90.3% tested positive. ConclusionsThe overall sensitivities of the three Ag-RDTs were 68.6%-75.0%, increasing to at least 85.6% after the viral load cut-off was applied. For SD-Biosensor, the diagnostic accuracy with OP-N and NP sampling was comparable. Over 55% of false negative Ag-RDT participants tested positive during follow-up.
RESUMO
If a health care workers (HCW) experiences COVID-19 associated symptoms, SARS-CoV-2 testing must be performed as soon as possible, to prevent transmission of the virus and to guarantee continuity of care. The gold standard for the detection of SARS-CoV-2, RT-PCR, has a high sensitivity but usually takes 6-8 hours. Lateral flow antigen assays take only 15-30 minutes and do not need any high tech equipment. In a prospective study of our hospitals HCWs, we evaluated the sensitivity of the Panbio COVID-19 Ag Rapid Test (Abbott) against the molecular test Aptima SARS-CoV-2 Assay (Hologic) which uses Transcription Mediated Amplification (TMA). TMA positive samples were further subjected to a quantitative real-time SARS-CoV-2 PCR to obtain Ct values as an indication of the viral load. Of 1101 HCWs included in the study between November 2020 and February 2021, 84 (7.6%) were TMA positive, of which 48 (57.1%) were antigen test positive. Most false negative antigen test results occurred if the duration of symptoms had been [≤]1 day or [≥]7 days. Sensitivities for symptom onset of [≤]1, 2 or 3 days were 47.1%, 63.0% and 66.7% respectively. The Panbio rapid test is fast and easy to perform, but is not a suitable SARS-CoV-2 test to confirm or exclude COVID-19 in HCWs with a very recent onset of symptoms.
RESUMO
BackgroundAntigen-based point of care tests for identification of SARS-CoV-2 may markedly enhance effectiveness of population-based controlling strategies. Previous studies have demonstrated acceptable sensitivity and high specificity compared to RT-qPCR in symptomatic individuals, but test performance for asymptomatic individuals is unknown. MethodsTest performance of the Panbio COVID-19 Ag Rapid Test (Abbott) was compared to RT-qPCR in a longitudinal cohort study of asymptomatic football players and staff members of professional football clubs. Based on timing of symptoms and prior and subsequent test results, positive RT-qPCR tests were categorized as pre-symptomatic, early or late infection or persistent RNA shedding. Findings2425 tests were performed in 824 individuals, of which 52 (6.3%) were SARS-CoV-2 positive based on RT-qPCR. There were 2406 paired sets from asymptomatic subjects for analysis. Sixteen Panbio tests were inconclusive, for which sensitivity analyses were performed (considering results as either positive or negative or being excluded). Sensitivity of Panbio ranged from 61.76% (95% CI 49.2-73.3) to 69.12% (95% CI: 56.7-79.8) and specificity from 99.53% (95% CI: 99.2-99.8) to 100% (95% CI: 99.8-100). Sensitivity of Panbio to detect subjects with pre-symptomatic/early infection (n= 42) ranged from 81.82% (95% CI: 67.3-91.8) to 90.91% (95% CI: 78.3-97.5) with specificity always above 99%. InterpretationIn asymptomatic subjects the Panbio COVID-19 Ag Rapid Test had sensitivity of 81.82% to 90.91% and specificity above 99% for identifying pre-symptomatic and early SARS-CoV-2 infection. FundingThis study was funded by the executing institutes. The Panbio COVID-19 Ag Rapid Tests were provided by the Ministry of Health, Welfare and Sport (VWS).
