Should IgM/IgG rapid test kit be used in the diagnosis of COVID-19?

Abstract

KEY FINDINGS

Current evidence does NOT support use of IgM/IgG rapid test kits for the definitive diagnosis of COVID-19 in currently symptomatic patients.

• The present standard for diagnosis of COVID-19 is through qualitative detection of COVID-19 virus nucleic acid via reverse transcription polymerase chain reaction (RT-PCR).

• Due to long turnaround times and complicated logistical operations, a rapid and simple field test alternative is needed to diagnose and screen patients.

• An alternative to the direct detection and measurement of viral load (RT-PCR) is the qualitative detection of specific antibodies to COVID-19. ELISA (discussed in a separate rapid review) and lateral flow immunoassay (LFIA) IgM/IgG rapid test kits are two currently available, qualitative, antibody tests for COVID-19.

• Two low quality clinical trials showed that there is insufficient evidence to support the use of IgM/IgG rapid test kits for the definitive diagnosis of COVID-19. Diagnostic accuracy varies greatly depending on the timing of the test. The test performed very poorly during the early phase of the disease (i.e., less than eight days from onset of symptoms).

• Existing guidelines do not recommend serologic antibody tests for the diagnosis of COVID-19 in currently symptomatic patients.