Patients and specimens
This study enrolled patients who visited Hanyang University Guri Hospital’s emergency department from March to June 2022. RT-PCR assays were performed for patients who decided to be admitted for further specific treatment. Patients with SARS-CoV-2-positive results in the RT-PCR assay within 45 days before the emergency department visit were excluded. Repeated visits by the same patient were considered individual cases. The Korean Triage and Acuity Scale (KTAS) classification was performed for all patients visiting the emergency department.7 Disease severity and urgency of treatment increased from KTAS level 5 to level 1. COVID-19-associated symptoms were fever, cough, sputum, rhinorrhea, dyspnea, or throat pain. This study was approved by the Institutional Review Board of Hanyang University Guri Hospital (2022-11-011), which waived the requirement for informed consent to participate in the study.
Two pairs of nasopharyngeal and oropharyngeal swabs from each patient were used for STANDARD M10 and Allplex assays. Specimens were obtained and transferred using a universal viral transport medium of RM Life Science (Seoul, Korea) or GeneTM gene transport medium (SG Medical, Seoul, Korea). STANDARD M10 assay was performed immediately after sample collection, and Allplex assay was performed within 12 h after sample collection. When discordant results occurred between STANDARD M10 and Allplex assays, the specimen subjected to STANDARD M10 assay was retested with Allplex assay to correct the influence that occurred from different specimens. The retest was performed within 48 h after sample collection, and the initial results of Allplex assay were replaced by the retest results. Samples were stored at 4℃ before subsequent tests.