As the third wave of coronavirus disease 2019 (COVID-19), largely fuelled by the Omicron variant of coronavirus, shows a decline in the country, the weekly cases for the week from February 21 to 27 witnessed a drop to below the 1-lakh mark.¹

Even though the current wave shows signs of ebbing, this is no time to be complacent. Infected people can continue to spread the virus through respiratory droplets via sneezing or coughing, and infect others. People can even get infected through contaminated surfaces.²

Therefore, taking adequate precautions and practicing COVID-appropriate behavior still remain key approaches to contain the spread of COVID-19. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load is high in the nasopharynx, saliva and throat.² Additionally, angiotensin-converting enzyme II (ACE2), the SARS-CoV-2 cell receptor, has been shown to be expressed on the oral mucosa and the epithelial cells of the tongue.³

Considering all this, maintaining optimum oral hygiene and reducing the viral load in the body’s reservoirs with high viral load becomes important to limit transmission. Gargling with a virucidal solution appears to be a potential intervention to attain viral clearance. Povidone-iodine (PVP-I) is a broad-spectrum antimicrobial agent which also has virucidal properties.⁴

Reports have shown that PVP-I can block the attachment of SARS-CoV-2 to oral and nasopharyngeal tissues. It can also reduce the viral particles in saliva and respiratory droplets.4 A randomized, four-arm study by Mohamed et al sought to determine the potential of regular gargling in eliminating SARS-CoV-2 in the oropharynx and nasopharynx.2 The investigators looked at the effects of gargling 3 times a day for 30 seconds, using PVP-I, essential oils and tap water, on viral clearance among COVID-19 patients. Five Stage 1 COVID-19 patients (asymptomatic state during the first 2 days of infection) were included in each group. Investigators noted that in the PVP-I group, SARS-CoV-2 was not detected in any of the participants on Day 4, Day 6 and Day 12. Among participants in the essential oils group, there were 4 negative samples and 1 either positive or indeterminate result all through Day 4, Day 6 and Day 12. In the tap water group, 2 samples were negative and the other 3 were either positive or indeterminate on Day 4, Day 6 and Day 12. Among participants in the control group, one sample was negative on Day 4 and Day 12; other samples yielded either positive or indeterminate result. Viral clearance was attained in 100%, 80%, 20% and 0% of the patients in PVP-I, essential oils, tap water and control group, respectively. There was high viral clearance rate for PVP-I as early as 4 days following the intervention. The study thus showed that regular gargling with PVP-I could achieve early viral clearance among Stage 1 patients.

Use of PVP-I gargle or mouthrinse could thus play a vital role in limiting transmission of SARS-CoV-2 and help contain the spread of COVID-19.

References

1. Weekly Covid cases fall below 1 lakh, lower than tally in 1st wk of 3rd wave. Available from: https://health.economictimes.indiatimes.com/news/industry/weekly-covid-cases-fall-below-1-lakh-lower-than-tally-in-1st-wk-of-3rd-wave/89881284. Accessed February 28, 2022.
2. Mohamed NA, Baharom N, Sulaiman WSW, et al. Early viral clearance among COVID-19 patients when gargling with povidone-iodine and essential oils - A clinical trial. Available from: https://www.medrxiv.org/content/10.1101/2020.09.07.20180448v1.full.pdf. Accessed February 28, 2022.
3. 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;21(3):101584.
4. 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;57:39-45.