Routine procedures involving the upper aerodigestive tract may be associated with a risk of inadvertent transmission of the virus from asymptomatic patients with COVID-19 infection to healthcare workers. Since the nasal cavity and the pharynx are reservoirs for the SARS-CoV-2 virus, it has been proposed that application of viricidal agents like PVP-I in the pharynx and nasal cavity may reduce virus burden and consequent transmission.

PVP-I has been a widely used topical antiseptic for over six decades and has the broadest spectrum of antimicrobial action as compared to other commonly used antiseptics such as chlorhexidine. Several in vitro studies have confirmed the viricidal activity of PVP-I against many common respiratory viruses such as influenza, adenovirus, including similar coronaviruses (SARS and MERS). It is also active against rotavirus, Ebola, HIV, polyomavirus and hepatitis A. It has bactericidal activity against common oral bacteria such as Klebsiella pneumonia and Streptococcus pneumonia.

Several in vitro studies have demonstrated rapid inactivation of SARS and MERS viruses including other viruses such as influenza, with PVP-I gargles and throat spray. No mucosal irritation has been reported indicating good mucosal tolerance. However, topical oro-nasal PVP-I prophylaxis is contraindicated in cases of known iodine allergy or those undergoing radioiodine treatment. The authors have suggested a prophylactic treatment protocol for the application of topical povidone-iodine to the upper aerodigestive tract as a prophylactic measure to reduce the viral load thereby also reducing the risk of transmission of SARS-CoV-2 virus. This protocol includes 15 ml 1% PVP-I as a swish and spit for 30 seconds to be done by the patient before induction of anesthesia and application of 1% PVP-I to oral cavity and pharynx for all transoral procedures. The applied solution is left for 30 seconds. For any transnasal procedure, 10–20 ml 1% PVP-solution is placed into the nasal cavity. 

In conclusion, topical oronasal PVP-I may be used as an additional low-cost prophylaxis measure to reduce the risk of transmission associated with aerosol-generating procedures that are routinely done in ENT operating theatres in addition.

Naqvi SHS, et al. Am J Surg. 2021 Jan;221(1):162-167.