Field Validation of a Rapid Recombinase Aided Amplification Assay for SARS-CoV-2 RNA at Customs - Zhejiang Province, China, January 2021

Introduction: The best approach to preventing the importation of coronavirus disease 2019 (COVID-19) is enhancing the detection capacity at customs. The rapid detection is of utmost importance and therefore highly demanded. Methods: We conducted a field validation study of a duplex real-time reverse transcription recombinase-aided amplification (RT-RAA) assay in Zhoushan and Hangzhou customs, in Zhejiang Province, China. The reverse transcriptase polymerase chain reaction (RT-PCR) assay kit routinely used at customs was used in parallel, and the duration the two methods took to complete a specific number of samples was compared. Results: Among 506 samples collected, RT-RAA results were consistent with the RT-PCR results. The sensitivity and specificity were 100%, the total coincidence rate was 100%, and the Kappa value was 1 (P<0.05) for both methods. The RT-RAA kit took a significantly shorter time in testing the 20-200 samples than the RT-PCR kit. Discussion: The RT-RAA detection method is more efficient and suitable for use at customs than RT-PCR assay to realize rapid customs clearance of 200 or fewer samples.