Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is influenced by the type of transport medium: Implications for diagnosis and monitoring.

ABSTRACT

It is unclear if the use of a molecular transport medium (MTM) containing guanidine isothiocyanate (GITC) would be advantageous over the CDC recommended, commonly used viral transport medium (VTM). We retested 70 SARS-CoV2 cases by RT-PCR in varying stages of follow-up using MTM and VTM in parallel and found discrepant results of RNase P, E and N genes. Majority (81%) patients tested positive with MTM as compared with VTM (27.1%). Even patients who were sampled 3 weeks after diagnosis demonstrated a significant discrepancy in the positivity rates between MTM vs VTM raising concerns about the clinical utility of VTM.