Bacterial profile and associated factors of face mask contamination among health care workers

Extended and improper mask use may lead to increased bacterial contamination of the mask surface, highlighting the need to better understand patterns of microbial load and persistence on masks in clinical settings. This study aims to investigate the bacterial contamination in face masks used by healthcare workers (HCWs), identify the predominant bacterial species, and evaluate factors contributing to contamination. A cross-sectional study was conducted among 400 HCWs in secondary and tertiary hospitals in a metropolitan Indian city. Data was collected through interviews on demographics and hygiene. Mask and indoor air samples were analysed using conventional cultures and the Automated VITEK-2 for identification. Bacterial contamination was found in 84.5% of masks and included strains of MRSA (1.5%) and MSSA (0.25%). While environmental samples mirrored mask flora, MRSA was found only on the inner mask surfaces, suggesting HCWs may be nasal carriers. Bacterial loads were highest in wards and lowest in the ICU, with significantly higher counts linked to poor hand hygiene. In Univariate analysis, factors such as higher age, gender, clinical setting of work, surgical mask, higher patient contact, working hours, hospital providing mask and duration of mask usage were found to be significantly associated with colony count. Multivariable quasi-Poisson regression analysis identified clinical setting of work (RR 1.69, CI 1.29–2.21), Female Gender (RR 0.79, CI 0.67–0.93), surgical mask (RR 1.30, CI 1.05–1.61), and hospital providing masks (RR 0.80, CI 0.66–0.98) as predictors for bacterial contamination. The high prevalence of bacterial contamination, including MRSA on masks, highlights the need for strict handling protocols, frequent replacement, and further research into the potential for cross-contamination and hospital-acquired infections.