Published on Sun Jun 20 2021

Evaluation of the Access Bio CareStartTM rapid SARS-CoV-2 antigen test in asymptomatic individuals tested at a community mass-testing program in Western Massachusetts

Suliman, S., Matias, W. R., Fulcher, I. R., Molano, F. J., Collins, S., Uceta, E., Zhu, J., Paxton, R. M., Gonsalves, S. F., Harden, M. V., Fisher, M., Meldrim, J., Gabriel, S., Franke, M. F., Hung, D., Smole, S. C., Madoff, L. C., Ivers, L. C.

CareStart has a high specificity and moderate sensitivity. The utility of RDTs, such as CareStart, in mass implementation should prioritize use cases in which a higher specificity is more important. Data on their performance in real-world community settings is paramount for their implementation.

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6
22
Abstract

BackgroundPoint-of-care antigen-detecting rapid diagnostic tests (RDTs) for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) represent a scalable tool for SARS-CoV-2 infections surveillance. Data on their performance in real-world community settings is paramount for their implementation. MethodWe evaluated the accuracy of CareStart COVID-19 Antigen test (CareStart) in a testing site in Holyoke, Massachusetts. We compared CareStart to a SARS-CoV-2 reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) reference, using anterior nasal swab samples. We calculated the sensitivity, specificity, and expected positive and negative predictive values at different SARS-CoV-2 prevalence estimates. ResultsWe performed 666 tests on 591 unique individuals. 573 (86%) were asymptomatic. There were 52 positive tests by RT-qPCR. The sensitivity of CareStart was 49.0% (95% Confidence Interval (CI): 34.8 - 63.4) and specificity was 99.5% (95% CI: 98.5 - 99.9). Among positive RT-qPCR tests, the median cycle threshold (Ct) was significantly lower in samples that tested positive on CareStart. Using a Ct [≤] 30 as a benchmark for positivity increased the sensitivity to 64.9% (95% CI: 47.5 - 79.8). ConclusionsCareStart has a high specificity and moderate sensitivity. The utility of RDTs, such as CareStart, in mass implementation should prioritize use cases in which a higher specificity is more important.