Evaluating the Effect of Gargling with Hydrogen Peroxide and Povidone‑Iodine on Salivary Viral Load of SARS‑CoV‑2: A Pilot Randomized Clinical Trial

Abstract

Background and Aim: This study evaluates the salivary viral load of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in  hospitalized patients and outpatients before and after gargling with 1% hydrogen peroxide and 0.25% povidone-iodine in comparison  with normal saline.

Patients and Methods: This clinical trial was conducted on 120 participants with laboratory‑confirmed coronavirus  disease 2019 (COVID-19) in two groups: outpatients (n = 60) and hospitalized patients (n = 60). In each group, the patients were randomly  divided into three subgroups of 20 based on their given mouthwash for gargling (hydrogen peroxide, povidone-iodine, or normal saline).  Two saliva samples were taken from each patient: the first one before gargling and the second one 10 minutes after gargling 10 ml of the  respected mouthwashes for 30 seconds. The TaqMan real‑time polymerase chain reaction (PCR) amplification of SARS‑CoV‑2 was used to measure the viral load.

Results: Saliva samples from 46% of patients were positive for coronavirus before gargling the  mouthwashes. The percentage of patients with an initial positive saliva sample was significantly higher in the outpatient group (83.3%)  than in the hospitalized group (5.4%) (P = 0.01). According to the findings, gargling any mouthwash similar to saline did not reduce the  viral load (P > 0.05).

Conclusion: The saliva of COVID-19 patients in the initial stage of the disease was more likely to contain SARS-CoV-2  than the saliva of the hospitalized patients. Gargling hydrogen peroxide or povidone-iodine did not reduce the salivary SARS-CoV-2 viral  load.