Rapid screening for severe acute respiratory syndrome coronavirus 2 infection with a combined point-of-care antigen test and an immunoglobulin G antibody test.

Kosuke Satoh,Ichiro Takeuchi,Shohei Imaki,Yutaro Ohyama,Takeru Abe,Kosuke Mori,Gheyath K. Nasrallah

doi:10.1371/journal.pone.0263327

Kosuke Satoh, Ichiro Takeuchi + Show 5 more

Open Access

https://doi.org/10.1371/journal.pone.0263327

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Abstract

Rapid screening and diagnosis of coronavirus disease 2019 in the emergency department is important for controlling infections. When polymerase chain reaction tests cannot be rapidly performed, rapid antigen testing is often used, albeit with insufficient sensitivity. Therefore, we evaluated the diagnostic accuracy of combining rapid antigen and antibody test results. This was a retrospective review of patients who visited our emergency department between February and May 2021 and underwent rapid antigen, immunoglobulin G antibody, and reverse transcription-polymerase chain reaction tests. The study included 1,070 patients, of whom 56 (5.2%) tested positive on reverse transcription-polymerase chain reaction. The sensitivity, specificity, and area under the curve of rapid antigen testing were 73.7%, 100.0%, and 0.87, respectively. The combined rapid antigen and antibody test result had improved diagnostic accuracy, with 91.2% sensitivity, 97.9% specificity, and an area under the curve of 0.95. The results of the rapid antigen and antibody tests could be combined as a reliable alternative to reverse transcription-polymerase chain reaction.

Highlights

The coronavirus disease 2019 (COVID-19) pandemic is a major worldwide problem [1]
We evaluated the diagnostic accuracy of a combination of rapid antigen and antibody tests for diagnosis of COVID19 in the acute phase, as this has not been sufficiently verified
Among the RT-PCRpositive patients, 94.6% had respiratory symptoms and 58.9% visited our emergency department (ED) within a week of symptom onset

Summary

Introduction

There are three main routes of virus transmission [2]: (i) inhalation of very fine respiratory droplets and aerosol particles [2,3,4,5]; (ii) deposition of respiratory droplets and particles on exposed mucous membranes in the mouth, nose, or eyes; and (iii) contact between mucous membranes and hands soiled either directly by virus-containing respiratory fluids or indirectly by touching surfaces contaminated with the virus Of note, it is still controversial whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes airborne infection and whether N95 masks are superior to surgical masks for protection against infection [6]. Its sensitivity is low (68.9%; 95% confidence interval [CI]: 61.8–75.1) [11], and its diagnostic ability decreases 7 days after onset of disease, with sensitivities of 78.3% (95% CI: 71.1–84.1) and 51.0% (95% CI: 40.8–61.0) in the first and second week, respectively [11] Even if these rapid antigen test results were negative, the patients may still have been infected. We evaluated the diagnostic accuracy of a combination of rapid antigen and antibody tests for diagnosis of COVID19 in the acute phase, as this has not been sufficiently verified

Materials and methods

Study design

Results

Discussion

Conclusion