Challenges and experiences of the SARS-CoV-2 pandemic in molecular diagnostics

Although the SARS-CoV-2 pandemic has been a great challenge for the diagnostic capacities, it also proved to be a unique source of experience. While previously PCR tests had overwhelmingly been used for targeted diagnostic and quantitative follow-up testing, screening and (initially) release tests became far more prevalent during the pandemic. It was well to be seen that the forced pace of bringing tests to market often gave way to not fully mature concepts. The PCR method is based on the detection of sequences, the proportions of which are likely to alter throughout the course of the disease. It is becoming increasingly clear that different target genes might be the best suitable for diag-nostic, screening and release testing. Even with specific assays, an unprecedentedly high number of tests might result in the inflation of the positive predictive value, when the true prevalence of the infection remains very low among the tested individuals. Here we try to summarize some of the potentially most relevant diagnostic conclusions of the pandemic so far according to our own data and the literature.