# Preemptive rapid antigen test as an emergency measure during coronavirus disease 2019 outbreaks

## TL;DR

This study shows that rapid antigen tests can be effective for early detection of COVID-19 during outbreaks when followed by RT-PCR.

## Contribution

The study introduces a preemptive testing model combining RAT and RT-PCR for rapid outbreak response.

## Key findings

- Rapid antigen test sensitivity was 0.82 and specificity was 1.00 in a high-density outbreak setting.
- False-negative rates were slightly higher but not statistically significant compared to serial screening studies.
- The preemptive RAT strategy did not increase diagnostic inaccuracy compared to serial screening.

## Abstract

We acknowledge that the rapid antigen test (RAT) has several advantages, including faster results, cost-effectiveness, and suitability for on-site self-testing. However, there is still controversy regarding the performance of the RAT for coronavirus disease 2019 (COVID-19). The aim of this study was to evaluate RAT screening in a COVID-19 outbreak situation.

In this study, we developed a preemptive testing model in which a RAT was immediately followed by reverse transcriptase polymerase chain reaction (RT-PCR) during a single screening in a high-density community outbreak to rapidly prevent transmission. The RAT and RT-PCR were performed using the Flowflex™ SARS-CoV-2 Antigen Test Kit and the SARS-CoV-2 Nucleic Acid Test Kit, respectively. Furthermore, we retrospectively investigated diagnostic data from a total of 813 participants. Then, we analyzed sensitivity and specificity using RT-PCR as the reference method. In addition, we compared our data with those from another published study involving serial screening using the chi-squared test, in which 541 samples were analyzed.

Our study showed that the sensitivity and specificity of the RAT were 0.82 and 1.00, respectively. We found a slightly higher false-negative rate, corresponding to decreased sensitivity, in our data compared to the previous study; however, the difference was not statistically significant. In addition, there was no statistically significant difference in the false-positive rate, corresponding to specificity, between the two studies.

The current results indicate that a RAT with a single screening does not pose an additional risk of inaccurate diagnosis of COVID-19 compared to serial screening. The strategy of a preemptive RAT might be an effective emergency measure to prevent COVID-19 transmission at an early stage of an outbreak.