Laboratory testing of SARS‐CoV, MERS‐CoV, and SARS‐CoV‐2 (2019‐nCoV): Current status, challenges, and countermeasures

Emerging and reemerging infectious diseases are global public concerns. With the outbreak of unknown pneumonia in Wuhan, China in December 2019, a new coronavirus, SARS‐CoV‐2 has been attracting tremendous attention. Rapid and accurate laboratory testing of SARS‐CoV‐2 is essential for early discovery, early reporting, early quarantine, early treatment, and cutting off epidemic transmission. The genome structure, transmission, and pathogenesis of SARS‐CoV‐2 are basically similar to SARS‐CoV and MERS‐CoV, the other two beta‐CoVs of medical importance. During the SARS‐CoV and MERS‐CoV epidemics, a variety of molecular and serological diagnostic assays were established and should be referred to for SARS‐CoV‐2. In this review, by summarizing the articles and guidelines about specimen collection, nucleic acid tests (NAT) and serological tests for SARS‐CoV, MERS‐CoV, and SARS‐CoV‐2, several suggestions are put forward to improve the laboratory testing of SARS‐CoV‐2. In summary, for NAT: collecting stool and blood samples at later periods of illness to improve the positive rate if lower respiratory tract specimens are unavailable; increasing template volume to raise the sensitivity of detection; putting samples in reagents containing guanidine salt to inactivate virus as well as protect RNA; setting proper positive, negative and inhibition controls to ensure high‐quality results; simultaneously amplifying human RNase P gene to avoid false‐negative results. For antibody test, diverse assays targeting different antigens, and collecting paired samples are needed.