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

Table 5

Study characteristics of SARS-CoV-2 viral load in oropharyngeal fluid combined with saliva indicated by C_T values.

Author	Reference	Study design	Viral load (CT value)	SD and IQR	Method to detect viral load	Saliva sample source	% SARS-CoV-2 positive	Total cohort size	Days onset	Symptomatic	Asymptomatic
Hung (2020)	[49]	Cross-sectional	Oropharyngeal saliva median: 34.5	IQR: 32.5–41	RT-PCR	Produce saliva coughed up from the posterior oropharynx (clearing the throat)	89%	18	4–30	CT value: 32	CT value: 34.83
			Mean: 36.1	SD: 6.9						SD: 2.21 n = 12	SD: 0.42 n = 1
Hon-Kwan Chen (2020)	[50]	Cross-sectional	Posterior oropharyngeal saliva median: 29.7 mean: 31.8	IQR posterior saliva: 27.2–37.2	RT-PCR	Spit posterior oropharyngeal saliva by coughing up via clearing the throat	Posterior saliva: 5.2% NPS: 10.3%	58	NR	NR	NR
			NPS median: 26.8 mean: 27	SD: 12.6
				IQR NPS: 20.7–33.5
				SD: 12.2

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