Impact of Oral Rinsing with Octenidine Based Solution on SARS-CoV-2 Loads in Saliva of Infected Patients an Exploratory Study

Abstract

Objective: In this study, the in-vivo effect of an antiseptic mouth rinse with Octenisept plus phenoxyethanol (OCT + PE) on the oral SARS-CoV-2 load was investigated.

Material and methods: In eight COVID-19 patients, saliva samples were obtained before mouth rinsing and at five time points post rinsing with OCT + PE (n = 47 saliva samples in total). SARS-CoV-2 RNA was detected and quantified by RT-qPCR and virus isolation in cell culture was performed to assess for infectivity.

Results: Immediately after mouth rinsing (1 min), a significant reduction of the SARS-CoV-2 RNA loads in saliva was achieved (p = 0.03) with 7/8 participants having SARS-CoV-2 RNA levels undetectable by RT-qPCR. At later time points, RNA levels returned to baseline levels in all study participants. Infectivity of saliva samples was demonstrated by successful virus isolation from saliva samples collected at later time points.

Conclusions: This study highlights that saliva samples from COVID-19 patients are infectious and demonstrates that mouth rinsing with OCT + PE temporarily leads to a significant reduction of the SARS-CoV-2 load in saliva.

Clinical relevance: Mouth rinsing with OCT + PE could provide a simple, rapid, and efficient method for SARS-CoV-2 infection prevention, particularly in the field of dental and respiratory medicine.

Keywords: SARS-CoV-2; octenidine; oral rinsing.

Figure 1

Octenidine dihydrochloride (OCT) plus phenoxyethanol effectively reduces detectable viral RNA in the saliva of SARS-CoV-2 positive individuals. SARS-CoV-2 RNA levels in the saliva of 8 subjects as quantified by RT-qPCR pre-rinsing with OCT plus phenoxyethanol (0 min) and 1, 30, 60, 240 and 360 min after rinsing with OCT plus phenoxyethanol are illustrated. RNA levels < LoD were set to 1 × 10⁰ copies/mL to allow for logarithmic presentation. Median RNA levels for each time point and 95% CI are indicated. Significant differences are indicated by asterisk (* = p < 0.05, unpaired t-test). Circles represent individual participant values with circles highlighted in light turquoise represent infectious samples as proved by successful virus isolation.

Figure 2

SARS-CoV-2 RNA kinetics of the included 8 subjects: SARS-CoV-2 RNA load [copies/mL] in saliva samples at the analyzed time points is illustrated. The dashed light grey line corresponds to the limit of detection of the RT-qPCR used [14]. The points marked with a green asterisk (time points 240 h subject #5, 360 h subject #6) correspond to infectious samples from which virus isolation was successful.