Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), is known to spread among humans through inhalation of respiratory droplets, saliva, or by direct contact with contaminated surfaces.¹

SARS-CoV-2 has been identified in the saliva of infected patients. Hence, the oral cavity can potentially transmit COVID-19. Moreover, the cell receptor of SARS-CoV-2, angiotensin-converting enzyme II (ACE2), is expressed on the oral mucosa and the epithelial cells of the tongue.²

Therefore, adequate oral hygiene and controlling the viral load in saliva assumes significance in order to curb the spread of COVID-19. Mouthwashes with antimicrobial properties are an important part of oral hygiene. Povidone-iodine (PVP-I) is a broad-spectrum antimicrobial agent, with potential efficacy against both enveloped and non-enveloped viruses.^1,2 Studies have reported that PVP-I can inactivate SARS-CoV-2 and inhibit the attachment of the virus to oral and nasopharyngeal tissues.¹

Anderson et al conducted an in vitro study to determine the virucidal activity of topical and oral PVP-I products, including gargle and mouthwash, against SARS-CoV-2. All the studied products - antiseptic solution, skin cleanser, gargle and mouth wash and throat spray – could attain ≥99.99% virucidal activity against the virus. This represented ≥ 4 log₁₀ reduction in virus titer within a contact time of 30 seconds.³

Frank and colleagues have also stated in their review that PVP-I is safe to use at concentrations up to 2.5% for up to 5 months and can cause rapid inactivation of coronaviruses, even when used for as little as 15 seconds.⁴

The available evidence supports the virucidal properties of PVP-I against SARS-CoV-2. Antimicrobial PVP-I mouthwash can therefore serve as a potential preventive approach, as a preprocedural mouthwash in healthcare settings, and in the community at large, to check the spread of the virus. 

References

1. Chopra A, Sivaraman K, Radhakrishnan R, et al. Can povidone iodine gargle/mouthrinse inactivate SARS-CoV-2 and decrease the risk of nosocomial and community transmission during the COVID-19 pandemic? An evidence-based update. Jpn Dent Sci Rev. 2021 Nov; 57: 39-45.
2. Elzein R, Abdel-Sater F, Fakhreddine S, et al. In vivo evaluation of the virucidal efficacy of chlorhexidine and povidone-iodine mouthwashes against salivary SARS-CoV-2. A randomized-controlled clinical trial. J Evid Based Dent Pract. 2021 Sep; 21(3): 101584.
3. Anderson DE, Sivalingam V, Kang AEZ, et al. Povidone-Iodine Demonstrates Rapid In Vitro Virucidal Activity Against SARS-CoV-2, The Virus Causing COVID-19 Disease. Infect Dis Ther. 2020 Sep;9(3):669-675.
4. Frank S, Capriotti J, Brown SM, Tessema B. Povidone-Iodine Use in Sinonasal and Oral Cavities: a Review of Safety in the COVID-19 Era. Ear Nose Throat J. 2020;99(9):586-93.