[SARS-CoV-2 antigen rapid tests].

BACKGROUND

For detection of SARS-CoV-2-infected persons ("severe acute respiratory syndrome coronavirus 2") quantitative Real-Time PCR (qRT-PCR) remains the gold standard. SARS-CoV‑2 antigen-detecting rapid diagnostic tests (Ag-RDTs) have the advantage of being fast and simple to use at any location. According to previous studies, Ag-RDTs seem to have poorer sensitivity and specificity. There are currently a few hundred Ag-RDTs available, but many of them have not been independently evaluated.

OBJECTIVES

Evaluation of diagnostic performance of rapid antigen tests detecting SARS-CoV‑2 from 6 different manufacturers.

MATERIALS AND METHODS

We performed Ag-RDTS with naso- and oropharnygeal swabs from laboratory routine which had had already resulted in a positive qRT-PCR test. To exclude possible dilution effects when samples were used for a second time, we also performed qRT-PCR analytics for already used samples. The initially measured Ct values could be confirmed.

RESULTS

Ag-RDTs showed differences in discrimination between positive and negative results. In samples with lower virus concentrations (Ct value > 30), the results were not reliable and the discrimination between negative and positive results was not unambigious.

CONCLUSIONS

Ag-RDTs with high sensitivity allow the identification of highly contagious patients anywhere. There are differences between manufacturers which are important when testing patients. An independent transparent evaluation of Ag-RDTs is necessary.