Laboratory diagnostics for SARS-CoV-2 plays a crucial role in the COVID-19 pandemic. It is not only important for diagnostic clarification, but also plays a key role in assessing the epidemiological development and strategies to slow down the pandemic, and provides arguments for enforcement or relaxation of containment measures .
Currently, direct pathogen detection by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) is the most commonly used acute diagnostic method. However, current publications show that the sensitivity of qRT-PCR alone is not sufficient to adequately exclude false negative results. Factors here are the time point and the procedure for taking the samples. Furthermore, the virus is often no longer available in sufficient quantity for a positive detection after activation of the immune system [2, 3, 4]. Experts therefore call for further diagnostic test systems.
Scientists demonstrated that the combined detection of specific IgG and IgM antibodies against SARS-CoV-2 can have a higher diagnostic sensitivity than a corresponding qRT-PCR test [3, 4]. A combination of anti-SARS-CoV-2 IgM detection with qRT-PCR also increases the diagnostic sensitivity to over 90% compared to the sole detection of COVID-19 disease by qRT-PCR . Thus, the detection of immunoglobulins offers the possibility of additionally confirming a diagnosis [3, 4, 5, 6].
It is also possible to use antibody tests for epidemiological studies for example to determine the immune status of the population and the development of the pandemic . Antibody tests can also contribute to clarifying infection chains. The knowledge gained from this provides an important contribution to decision-making regarding the application, enforcement or relaxation of containment measures.