Source : The Journal of Infectious Diseases, 30 May 2020, jiaa305, https://doi.org/10.1093/infdis/jiaa305
We comparatively assessed sensitivities and specificities of four commercial ELISAs and two rapid tests in 77 patients with PCR confirmed SARS-CoV-2 infection, grouped by intervals since symptom onset. While test sensitivities were low (<40%) within the first 5 days post disease onset, IgM-, IgAand total antibody-ELISAs increased in sensitivity to >80% between the 6th and 10th day post symptom onset. The evaluated tests (including IgG and rapid tests) provided positive results in all patients at or after the 11th day post onset of disease. Specificities of the ELISAs were 83% (IgA), 98% (IgG) and 97% (IgM and total antibodies).
SARS-Coronavirus 2 (SARS-CoV-2), a new Betacoronavirus, is currently causing a massive pandemic with severe consequences for the health-care systems worldwide [1, 2]. While polymerase chain reaction (PCR) based tests quickly became the cornerstone of SARS-CoV-2 diagnosis, the potential of antibody tests has not been comprehensively evaluated. Depending on respective infection stages, antibody assays could nonetheless significantly complement PCR based testing [3, 4]. Multiple commercial enzyme-linked immunoassays and rapid tests (lateral flow immunossays) have recently become available, but their diagnostic ability has to be thoroughly evaluated and compared before they can be widely used in the clinical setting [5, 6]. Here, we compared the diagnostic ability of four ELISAs, which assess SARS-CoV-2-specific antibodies of immunoglobulin classes (Euroimmun SARS-CoV-2 IgA and IgG, Wantai SARS-CoV-2 IgM and total antibodies), and two rapid tests (Wantai SARS-CoV-2 Ab Rapid Test and 2019-nCoV IgG/IgM Rapid Test) in 77 patients with symptomatic SARS-CoV-2 infection.