A pilot study to see any Change of the Nasal and Oropharyngeal Microbiota with Prolonged Use of Medical Masks during the COVID-19 Outbreak

Roy, S.; Majumder, P.; Bhattacharjee, K.

Background: The outbreak of coronavirus disease 2019 (COVID-19) has played havoc on the healthcare system and society. Many international guidelines have put forward various measures to control the spread and, using various quality masks seems to be the most important amongst them. This was a cross-sectional pilot study to see any alterations in the bacterial flora of the nasal and the oropharyngeal (OP) microbiota with the use of medical masks over prolonged periods during this COVID-19 outbreak. Methods: Nasal and oropharyngeal swabs were collected using proper international guidelines from 30 healthy healthcare workers matching pre-set inclusion criteria, who gave written informed consent. The swabs were used for gram stain as well as culture and sensitivity analysis using standard methods. Results: In general, we found that the oropharyngeal microflora harboured a more diverse population of bacteria (n=13) than the nasal microflora (n=5). The predominant bacterial flora was found to Staphylococcus epidermidis in the nasal cavity and Streptococcus viridans in the oropharyngeal cavity. There was no growth in 8 (26.68%) samples of oropharynx and 3 (10%) of nasal samples, with one patient having no growth in both the samples. The commonest resistant antibiotic from both the cavity cultures was benzylpenicillin (nasal flora 80% and OP flora 47.37%). Conclusion: This small pilot study has shown a reassuring aspect of no change in the typical bacterial microflora species of the nasal and OP cavity with prolonged use of medical masks. This is the first study to show this convincing evidence during the COVID-19 outbreak and also in healthy healthcare workers who have to wear masks over long durations.