key: cord-332080-923jpec0 authors: Lai, Chih-Cheng; Wang, Cheng-Yi; Ko, Wen-Chien; Hsueh, Po-Ren title: In vitro diagnostics of coronavirus disease 2019: technologies and application date: 2020-06-05 journal: J Microbiol Immunol Infect DOI: 10.1016/j.jmii.2020.05.016 sha: doc_id: 332080 cord_uid: 923jpec0 Abstract Laboratory-based diagnostic measures including virological and serological tests are essential for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Real-time reverse transcription-polymerase chain reactions (rRT-PCR) can detect SARS-COV-2 by targeting open reading frame-1 antibodies (ORF1ab), envelope protein, nucleocapsid protein, RNA-dependent RNA polymerase genes, and the N1, N2, and N3 (3N) target genes. Therefore, rRT-PCR remains the primary method of diagnosing SARS-CoV-2 despite being limited by false-negative results, long turnaround, complex protocols, and a need for skilled personnel. Serological diagnosis of coronavirus disease 2019 (COVID-19) is simple and does not require complex techniques and equipment, rendering it suitable for rapid detection and massive screening. However, serological tests cannot confirm SARS-CoV-2, and results will be false-negative when antibody concentrations fall below detection limits. Balancing the increased use of laboratory tests, risk of testing errors, need for tests, burden on healthcare systems, benefits of early diagnosis, and risk of unnecessary exposure is a significant and persistent challenge in diagnosing COVID-19. (Hangzhou Bigfish Bio-tech Co., Ltd., Zhejiang, China) was recently registered 127 as a CE-IVD for detecting SARS-CoV-2 ORF-1ab and N genes in 128 nasopharyngeal swabs, sputum, and BAL fluids. This kit has a reported LOD of 129 < 2 × 10 2 copies/mL. 25 130 ARGENE® SARS-COV-2 R-GENE® (bioMérieux SA., Marcy-l'Étoile, 131 France) was developed to detect SARS-CoV-2 RdRp, N, and E genes in 132 nasopharyngeal swabs. The LOD was determined from an inactivated viral 133 strain spiked in a nasopharyngeal swab sample at 0.43 TCID 50 /mL. This test 134 kit is presently available only for research purposes (Table 2) . 26 135 The Novel Coronavirus (2019 nCoV) RT-PCR assay (Dynamiker 136 Biotechnology (Tianjin) Co., Ltd., Tianjin, China) can detect the target genes, 137 ORF-1ab, N, and actin, within 1.5 h from oropharyngeal and nasopharyngeal 138 swabs, sputum, BAL fluid, serum, plasma, conjunctival swabs, and feces. The 139 reported detection range is 2 × 10 2 copies/mL (LOD) to 2 × 10 8 copies/mL. 27 140 The performance of this assay is presently under evaluation. 141 The product, Xpert ® Xpress SARS-CoV-2 (Cepheid Inc.) detects 142 SARS-CoV-2 RNA (N2 and E genes) in nasopharyngeal swabs, aspirates or 143 wash specimens within 45 minutes, and received EUA from the USFDA during 144 March, 2020. 28 The claimed LOD for the assay is 250 copies/mL. The 145 performance of the Xpress SARS-CoV-2 test was clinically evaluated in 146 patients with respiratory illnesses from whom contrived nasopharyngeal swab 147 samples were collected into viral transport media. The samples were then 148 spiked with AccuPlex SARS-CoV-2 (a recombinant Sindbis virus particle 149 containing the target sequences of the SARS-CoV-2 genome) at ~2-, 3-, and 150 5-fold LOD concentrations. The results were in 100% agreement with the 151 predicted results of the AccuPlex SARS-CoV-2 spiked, and negative samples. 152 The BioFire® COVID-19 test includes assays for SARS-CoV-2a, 153 SARS-CoV-2d, and SARS-CoV-2e to detect SARS-CoV-2 ORF1ab and OR8 154 sequences in nasopharyngeal swabs, and is a qualitative test on FilmArray® 155 2.0 or FilmArray® Torch systems. The LOD was 3.3 E+02 GC/mL. This 156 product has received USFDA EUA to detect SARS-CoV-2 RNA. 29 Although co-infection in patients with COVID-19 is rare, it has been 208 reported. 8, 9, 40 Therefore, tests that can screen for multiple pathogens, including 209 SARS-CoV-2, provide the additional benefit of detecting possible co-infections, 210 leading to the administration of appropriate antimicrobial agents. Serological tests that can detect SARS-CoV-2 IgG-IgM antibodies are simpler 248 than rRT-PCR, and do not require complicated equipment and protocols 249 (Table 3) . Thus, these tests can be used for rapid detection and massive 250 screening, particularly for asymptomatic carriers. During the previous SARS 251 epidemic, the IgM antibody was the first line of defense during viral infections 252 and was detectable in blood samples from patients after 3 -6 days. 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In vitro diagnostic assays for COVID-19: recent advances and 687 emerging trends Policy for diagnostics testing in 690 laboratories certified to perform high complexity testing under CLIA prior to 691 emergency use authorization for coronavirus disease-2019 during the 692 public health emergency y-testing-under-clia-prior 8-13 days: 86.1% ≥14 days: 100% Specificity: 99 days: 88.1% ≥14 days: 100%/ Specificity: 99.8% 18 min CE-IVD Conformité Européenne in vitro diagnostic device Emergency Use Authorization; LFIA, lateral flow immunoassay; NA, not available; RUO, research use only; TAT, turnaround time; US FDA, Food and Drug Administration of the 52 United States