A comparison of a SARS-CoV-2 rapid-test and serological-test in a Public Health Hospital

Abstract

Introduction: Nowadays, with the start of the vaccination campaign is very important to assess the extent of exposure of the population and identifying rapid, sensitive and accurate test to quickly identify new cases of SARS-CoV-2. The rapid test, cheap and easy to perform, is therefore very useful in developing countries, where the vaccination campaign has not yet reached adequate coverage.

Methodology: We compared the VivaDiag COVID-19 IgM/IgG Rapid Test (VivaCheck Biotech Co., Ltd) with the Roche Elecsys Anti-SARS-CoV-2 (Roche Diagnostics, Rotkreuz, Switzerland) to recognize past infections and to compare VivaDiag COVID-19 IgM/IgG Rapid Test (VivaCheck Biotech Co., Ltd) with Abbott Real Time PCR SARS-CoV-2 assay to recognize infection during its acute phase so that it's possible to evaluate the use of commercially available assays in clinical practice.

Results: Of the 1,100 patients tested with serological and rapid test, 1,085 were negative both to serological and rapid test, 4 patients were positive at rapid (2 for IgM and 2 for IgG) but negative serological test, 11 patients were positive at serological test but negative to rapid. Of the 300 tested with oropharyngeal swab and rapid test, 294 were negative both to swab and rapid test, 2 positives both to swab and rapid test, 3 positives at swab but negative at rapid test, 1 negative at swab but positive at rapid test.

Conclusions: the combined use of these tests according to the specific needs of users, allows a reliable identification of infected patients in the acute phase, distinguishing them from subjects with an antibody response from a previous infection.

Keywords: SARS-CoV-2; antibody response; asymptomatic subjects; rapid test; serological test.