CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel For Emergency Use Only

The FDA EUA PCR assays for SARS-CoV-2 are qualitative (detected vs. not detected) rather than quantitative assays that determine that amount of virus in a sample. Higher Ct values correlate with less SARS-CoV-2 RNA in the sample. Although attempts to culture virus from upper respiratory specimens have been largely unsuccessful when Ct values are high2, SARS-CoV-2 PCR Ct values cannot be interpreted as a measure of viral burden, are not standardized by RT-PCR platform, and have not been approved by the FDA for use in clinical management. While the CDC does not recommend the use of Ct values for clinical management, they may be useful in the context of laboratory and clinical information available for a patient. Note that Ct values are not included routinely in lab reports and may be difficult to retrieve