J Korean Med Sci.  2020 May;35(20):e195. 10.3346/jkms.2020.35.e195.

Clinical Significance of a High SARS-CoV-2 Viral Load in the Saliva

• Yoon JG
• Yoon J
• Song JY
• Yoon SY
• Lim CS
• Seong H
• Noh JY
• Cheong HJ
• Kim WJ

• KMID: 2500852
• DOI: http://doi.org/10.3346/jkms.2020.35.e195

Abstract

Background
Patients with coronavirus disease 2019 (COVID-19) can unknowingly spread the virus to several people during the early subclinical period.
Methods
We evaluated the viral dynamics in various body fluid specimens, such as nasopharyngeal swab, oropharyngeal swab, saliva, sputum, and urine specimens, of two patients with COVID-19 from hospital day 1 to 9. Additional samples of the saliva were taken at 1 hour, 2 hours, and 4 hours after using a chlorhexidine mouthwash. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load was determined by real-time reverse transcriptase polymerase chain reaction (rRT-PCR).
Results
SARS-CoV-2 was detected from all the five specimens of both patients by rRT-PCR. The viral load was the highest in the nasopharynx (patient 1 = 8.41 log10 copies/mL; patient 2 = 7.49 log10 copies/mL), but it was also remarkably high in the saliva (patient 1 = 6.63 log10 copies/mL; patient 2 = 7.10 log10 copies/mL). SARS-CoV-2 was detected up to hospital day 6 (illness day 9 for patient 2) from the saliva of both patients. The viral load in the saliva decreased transiently for 2 hours after using the chlorhexidine mouthwash.
Conclusion
SARS-CoV-2 viral load was consistently high in the saliva; it was relatively higher than that in the oropharynx during the early stage of COVID-19. Chlorhexidine mouthwash was effective in reducing the SARS-CoV-2 viral load in the saliva for a short-term period.

Keyword

SARS-CoV-2; COVID-19; Viral Load; Saliva; Chlorhexidine

Figure

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  Fig. 1 Viral dynamics of severe acute respiratory syndrome coronavirus 2 in patient 1 (A) and 2 (B): viral load from serial nasopharyngeal, oropharyngeal, saliva, sputum, and urine samples.NP = nasopharynx, OP = oropharynx.

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  Fig. 2 Impact of chlorhexidine mouthwash on the severe acute respiratory syndrome coronavirus 2 viral load in the saliva.HD = hospital day.

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