June 15, 2020

Nasal-Swab Testing Misses Patients with Low SARS-CoV-2 Viral Loads

Category: Article Summary

Topic: Testing and Treatment

• [pre-print, not peer reviewed] Callahan et al. compared results of nasal specimens under 3 transport conditions, traditional viral transport media (VTM), GITC transport medium, and dry swabs, to those of standard nasopharynx swabs collected at the same time among 308 individuals. They observed high concordance (Cohen’s kappa >0.8) only for patients with viral loads (VL) from the nasal samples >1000 copies/mL. There was low concordance (Cohen’s kappa = 0.49) for those with VL<1000 copies/mL.  

Callahan et al. (June 14, 2020). Nasal-Swab Testing Misses Patients with Low SARS-CoV-2 Viral Loads. Pre-print downloaded June 15 from https://doi.org/10.1101/2020.06.12.20128736