Cancer Diagnosis Program | Biorepositories and Biospecimen Research Branch

Search BRD Papers

A Direct Comparison of Enhanced Saliva to Nasopharyngeal Swab for the Detection of SARS-CoV-2 in Symptomatic Patients.

Author(s): Procop GW, Shrestha NK, Vogel S, Van Sickle K, Harrington S, Rhoads DD, Rubin BP, Terpeluk P

Publication: J Clin Microbiol, 2020, Vol. 58, Page

PubMed ID: 32883744 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   This study compared detection of SARS-CoV-2 in saliva/oropharyngeal secretion specimens to matched nasopharyngeal swab specimens. Patients (n=216, 18-82 years old) with symptoms of COVID-19 were instructed to sniff strongly to gather nasal secretion/mucus into the oropharynx, cough to produce phlegm, and then to collect secretions and additional saliva in a sterile specimen collection container. Nasopharyngeal swab specimens were then collected by a healthcare professional (details not provided) and placed in 0.9% normal saline. Specimens were refrigerated at the collection site and then transported to the laboratory in insulated coolers with ice packs. RNA was extracted the same day as collection with the MagNA Pure System and SARS-CoV-2 RNA was detected by real-time RT-PCR using the CDC 2019 nCoV real-time RT-PCR diagnostic panel. The nasopharyngeal swab specimen result was used as the reference (CT value cut-off for a positive result not provided) to calculate the positive and negative percent agreement for the matched saliva/oropharyngeal secretion specimen.

   Summary of Findings:

   Positive percent agreement between the nasopharyngeal and saliva/oropharyngeal specimen for SARS-CoV-2 RNA detection was 100% for the 38 nasopharyngeal specimens that were positive for SARS-CoV-2 RNA in the nasopharyngeal specimen. Negative percent agreement between the nasopharyngeal and saliva/oropharyngeal specimen was 99.4% for the remaining 178 specimens that were negative in the nasopharyngeal specimen. The one discordant case yielded a negative result in the nasopharyngeal specimen and a positive result in the saliva/oropharyngeal specimen. For this case, the presence of SARS-CoV-2 was confirmed in the saliva specimen using the Aptima SARS-CoV-2 transcription-mediated amplification assay. The mean CT value for SARS-CoV-2 RNA detection was significantly higher for saliva/oropharyngeal secretion specimens compared to nasopharyngeal swab specimens (24.16 versus 20.55, P=0.022) and there was no correlation between the CT values of the positive saliva/oropharyngeal secretion specimens and nasopharyngeal specimens (r=0.162; P=0.333).

   Biospecimens

   • Cell - Nasopharynx
   • Bodily Fluid - Saliva

   Preservative Types

   • None (Fresh)

   Diagnoses:

   • Pneumonia/Respiratory Infection

   Platform:

   Analyte	Technology Platform
   RNA	Real-time qRT-PCR

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Biospecimen Acquisition	Biospecimen location	Oral cavity/oropharynx Nasopharynx
   Real-time qRT-PCR Specific	Targeted nucleic acid	SARS-CoV-2
   Biospecimen Acquisition	Method of cell acquisition	Nasopharyngeal swab Saliva/oropharyngeal secretion

   View more