Interpreting Diagnostic Tests for SARS-CoV-2
2020
This viewpoint describes how to interpret two types of diagnostic tests commonly used for SARS-CoV-2 infections – reverse transcriptase-polymerase chain reaction (RT-PCR) and IgM and IgG enzyme-linked immunosorbent assay (ELISA) – and how the results may vary over time.
False-negative results mainly occurred due to inappropriate timing of sample collection in relation to illness onset and deficiency in sampling technique, especially of nasopharyngeal swabs. Specificity of most of the RT-PCR tests is 100% because the primer design is specific to the genome sequence of SARS-CoV-2. Occasional false-positive results may occur due to technical errors and reagent contamination.
The authors synthesize evidence and suggest a clinically relevant timeline for diagnostic markers for detection of COVID-19. They emphasize that most of the available data are for adult populations who are not immunocompromised, and that the time-course of PCR positivity and seroconversion may vary in children and other groups, including the large population of asymptomatic individuals who go undiagnosed without active surveillance.
Interpreting Diagnostic Tests for SARS-CoV-2
Source:
Sethuraman N, Jeremiah SS, Ryo A. Interpreting Diagnostic Tests for SARS-CoV-2. JAMA 2020; 323 (22): 2249–2251. https://doi.org/10.1001/jama.2020.8259