[Bronchoalveolar lavage fluid was used to diagnose two cases of 2019-nCoV infection]

Chinese Expert Consensus on the Nucleic Acid Detection of SARS-CoV-2

The coronavirus disease 2019 (COVID-19) has already become a pandemic wherein the infection's timely diagnosis has proven beneficial to patient treatment and disease control. Nucleic acid detection has been the primary laboratory diagnostic method for the detection of SARS-CoV-2. To ensure laboratory staff safety and quality nucleic acid testing, the Chinese Society of Laboratory Medicine formulated this consensus, based on the Chinese National Recommendations and previous literature for nucleic acid detection. A working group comprises 34 hospital professionals experience with real-time polymerase chain reactions (PCR) testing for SARS-CoV-2 drafted guidance statements during online discussions. A modified Delphi methodology was used in forming a consensus among a wider group of hospital professionals with SARS-CoV-2 detection experience. Guidance statements were developed for four categories: (I) specimen type, priority, collecting, transportation and receiving; (II) nucleic acid isolation and amplification; (III) quality control; (IV) biosafety management and decontamination. The modified Delphi voting process included a total of 29 guidance statements and final agreement. Consensus was reached after two rounds of voting. Recommendations were established for the detection of SARS-CoV-2 using real time PCR testing based on evidence and group consensus. The manuscript was evaluated against The Appraisal of Guidelines for Research & Evaluation Instrument (AGREE II) and was developed to aid medical laboratory staff in the detection of the ribonucleic acid (RNA) of SARS-CoV-2.

Evaluations of the serological test in the diagnosis of 2019 novel coronavirus (SARS-CoV-2) infections during the COVID-19 outbreak

We developed a chemiluminescence immunoassay method based on the recombinant nucleocapsid antigen and assessed its performance for the clinical diagnosis of severe acute respiratory syndrome coronavirus (SARS-CoV)-2 infections by detecting SARS-CoV-2–specific IgM and IgG antibodies in patients. Full-length recombinant nucleocapsid antigen and tosyl magnetic beads were used to develop the chemiluminescence immunoassay approach. Plasmas from 29 healthy cohorts, 51 tuberculosis patients, and 79 confirmed SARS-CoV-2 patients were employed to evaluate the chemiluminescence immunoassay method performance for the clinical diagnosis of SARS-CoV-2 infections. A commercial ELISA kit (Darui Biotech, China) using the same nucleocapsid antigen was used for the in-parallel comparison with our chemiluminescence immunoassay method. The IgM and IgG manner of testing in the chemiluminescence immunoassay method showed a sensitivity and specificity of 60.76% (95% CI 49.1 to 71.6) and 92.25% (95% CI 83.4 to 97.2) and 82.28% (95% CI 72.1 to 90.0) and 97.5% (95% CI 91.3 to 99.7), respectively. Higher sensitivity and specificity were observed in the chemiluminescence immunoassay method compared with the Darui Biotech ELISA kit. The developed high sensitivity and specificity chemiluminescence immunoassay IgG testing method combined with the RT-PCR approach can improve the clinical diagnosis for SARS-CoV-2 infections and thus contribute to the control of COVID-19 expansion.