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

Table 9

Study characteristics of SARS-CoV-2 viral load in sputum 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
Zheng (2020)	[7]	Retrospective cohort	Saliva + sputum (median log10): 5	IQR: 4–5.9	qRT-PCR	By coughing out saliva from the throat into a sterile container	100	96	0–55	NR	NR
			(1 × 10^5 copies/mL RNA)

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.