Comparing SARS-CoV-2 Viral Load in Human Saliva to Oropharyngeal Swabs, Nasopharyngeal Swabs, and Sputum: A Systematic Review and Meta-Analysis

Table 8

Study characteristics of SARS-CoV-2 viral load in oropharyngeal fluid combined with saliva indicated by copies/mL RNA.

Author	Reference	Study design	Viral load (copies/mL RNA)	SD and IQR	Method to detect viral load	Saliva sample source	% SARS-CoV-2 positive	Total cohort size	Days onset	Symptomatic	Asymptomatic
Gottsauner (2020)	[59]	Cross-sectional	Mouth and throat median: 1.8 × 10^3	IQR: 3.1 × 10^2–4.7 × 10^4 copies/mL	RT-PCR	Gargle mouth and throat with 20 mL 0.9% NaCl for 30 s	83	12	1–5	NR	NR
			Mean: 1.8 × 10^4	SD: 4.02 × 10^4
Lyngbakken (2020)	[60]	Randomized controlled trial	OPS (mean log10): 4.5 (3.17 × 10^4 copies/mL RNA)	NR: SD copies/mL RNA	RT-qPCR	Swabs were rotated for ten seconds on posterior oropharyngeal mucosal membrane (over both tonsils, soft palate, and posterior oropharynx)	49	51	2	NR	NR
			OPS (CT value mean): 34.54	SD OPS (CT value): 6.53
To (2020)	[1]	Observational cohort	Posterior oropharyngeal saliva (median log10): 5.2 (1.59 × 10^5 copies/mL RNA)	IQR: 4.1–7	RT-qPCR	Coughing by clearing throat and saliva from intubated patients were obtained by endotracheal aspiration	87	23	0–30	NR	NR

All median values, if present, are original and obtained from the publication. Authors were contacted for the original dataset. NR = not reported, ND = not detected, NPS = nasopharyngeal swab, OPS = oropharyngeal swab, SD = standard deviation, and IQR = interquartile range.