Current RT-qPCR to detect SARS-CoV-2 may give positive results for related coronaviruses

Some weeks after the first CoVID-19 outbreak, the World Health Organization published some real-time PCR (qPCR) protocols developed by different health reference centers. These qPCR designs are being used worldwide to detect SARS-CoV-2 in the population, to monitor the prevalence of the virus during the pandemic. Moreover, some of these protocols to detect SARS-CoV-2 have widely been applied to environmental samples for epidemiological surveillance purposes. In the present work, the specificity of these currently used RT-qPCR designs was validated in vitro using SARS-CoV-2 and highly related coronaviral genomic sequences and compared to performance of the commercially available GPS™ CoVID-19 dtec-RT-qPCR Test. Assays performed with SARS-CoV-2-related genomes showed positive amplification when using some of these qPCR methods, indicating they may give SARS-CoV-2 false positives. This finding may be particularly relevant for SARS-CoV-2 monitoring of environmental samples, where an unknown pool of phylogenetically close-related viruses may exist.