Method of Study
A study was done in Korea with two COVID-19 Patients, from the day 1-9 in hospital several specimens were taken the nasopharyngeal and oropharyngeal region using polyester flocked swabs, saliva and sputum samples also were collected and placed in separate tubes with virus transport medium.
On days 3 and 6, chlorhexidine gluconate solution mouthwash (0.12%, 15 mL) was done for 30 seconds after baseline specimen sampling on saliva and sputum samples. The same method of samples was collected to at 0 hours before mouthwash, 1 hour, 2nd hour, and 4th hour.
The presence of SARS-CoV-2 was confirmed by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR). RNA was extracted from the clinical samples using NucliSENS easyMAG platform (bioMérieux, Marcy-l’Étoile, France). rRT-PCR was performed using CFX96 real-time PCR detection system (Bio-rad, Hercules, CA, USA) and PowerChek 2019- nCoV real-time PCR kit (Kogenebiotech, Seoul, Korea), which targeted the E and RdRP genes of SARS-CoV-2. The primer and probe sequences were designed according to the previous study.7 The sample was defined as negative if the cycle threshold (Ct) value exceeded 35 cycles. Details regarding the rRT-PCR protocol are provided in the Supplementary Appendix. The RNA copy number was calculated from the Ct values using the standard curve generated by dilution of the plasmid DNA.
This study was approved by the Institutional Review Board of Korea University Guro Hospital (approval number: 2020GR0123). Informed consent was waived.
The viral load in saliva decreased for first 2 hrs after using chlorhexidine gluconate solution mouthwash (0.12%, 15 mL), but increased back to normal from 2hrs to 4hrs duration.
J Korean Med Sci. 2020 May 25;35(20):e195. English.
Published online May 20, 2020.