Saliva Is Comparable to Nasopharyngeal Swabs for Molecular Detection of SARS-CoV-2 (original) (raw)

BackgroundThe continued need for molecular testing for SARS-CoV-2 and potential for self-collected saliva as an alternative to nasopharyngeal (NP) swabs for sample acquisition led us to compare saliva to NP swabs in an outpatient setting, without restrictions to avoid food, drink, smoking, or tooth-brushing.MethodsA total of 385 pairs of NP and saliva specimens were obtained, the majority from individuals presenting for initial evaluation, and were tested on two high-sensitivity RT-PCR platforms: the Abbott m2000 and Abbott Alinity m (both with limits of detection [LoD] of 100 copies of viral RNA/mL).ResultsConcordance between saliva and NP was excellent overall (Cohen’s κ=0.93), for both initial and followup testing, for both platforms, and for specimens treated with guanidinium transport medium as preservative as well as for untreated saliva (κ=0.88-0.95). Viral loads were on average 16x higher in NP specimens than saliva specimens, suggesting that only the relatively small fracti...