COVID-19 Evidence Alerts
from McMaster PLUS^TM

AIM: This study aimed at investigating the efficacy of a 0.05% cetylpyridinium chloride-0.05% chlorhexidine (CPC-CHX) mouthwash in reducing viral load in the saliva as compared with sterile water.

MATERIALS AND METHODS: Forty SARS-CoV-2 positive patients were asked to dispense 4 mL of saliva. Half the patients rinsed for 60 s with 15 mL CPC-CHX, and the remaining patients rinsed with sterile water (control). Four millilitres of saliva were collected after 15, 30 and 60 min after rinsing. Quantitative reverse transcriptase polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) specific for SARS-CoV-2 nucleocapsid protein were performed. For ELISA, the intact (representing the active virus) to total virus load (I/T) was calculated.

RESULTS: SARS-CoV-2 copy numbers/mL from RT-qPCR tended to decrease in the control group, whereas in the CPC-CHX group, an increase was observed after T30. However, mixed linear model analysis revealed no statistical differences between groups (p = .124), time points (p = .616) and vaccinated or non-vaccinated patients (p = .953). Similarly, no impact of group (p = .880), time points (p = .306) and vaccination (p = .711) was observed for I/T ratio values.

CONCLUSIONS: Within the limitation of this study, there was no evidence that the intervention reduced salivary SARS-CoV-2 viral load during the course of 60 min. Therefore, commonly used pre-procedural rinsing might not be clinically relevant.