Cotton and Surgical Face Masks in Community Settings: Bacterial Contamination and Face Mask Hygiene

During the current COVID-19 pandemic, the use of face masks has become increasingly recommended and even mandatory in community settings. To evaluate the risk of bacterial cross-contamination, this study analyzed the bacterial bioburden of disposable surgical masks and homemade cotton masks, and surveyed the habits and face mask preferences of the Flemish population. Using culture approaches and 16S rRNA gene amplicon sequencing, we analyzed the microbial community on surgical and/or cotton face masks of 13 healthy volunteers after 4 h of wearing. Cotton and surgical masks contained on average 1.46 × 105 CFU/mask and 1.32 × 104 CFU/mask, respectively. Bacillus, Staphylococcus, and Acinetobacter spp. were mostly cultured from the masks and 43% of these isolates were resistant to ampicillin or erythromycin. Microbial profiling demonstrated a consistent difference between mask types. Cotton masks mainly contained Roseomonas, Paracoccus, and Enhydrobacter taxa and surgical masks Streptococcus and Staphylococcus. After 4 h of mask wearing, the microbiome of the anterior nares and the cheek showed a trend toward an altered beta-diversity. According to dedicated questions in the large-scale Corona survey of the University of Antwerp with almost 25,000 participants, only 21% of responders reported to clean their cotton face mask daily. Laboratory results indicated that the best mask cleaning methods were boiling at 100°C, washing at 60°C with detergent or ironing with a steam iron. Taken together, this study suggests that a considerable number of bacteria, including pathobionts and antibiotic resistant bacteria, accumulate on surgical and even more on cotton face masks after use. Based on our results, face masks should be properly disposed of or sterilized after intensive use. Clear guidelines for the general population are crucial to reduce the bacteria-related biosafety risk of face masks, and measures such as physical distancing and increased ventilation should not be neglected when promoting face mask use.

Survey of facial masks using behaviour during COVID-19 outbreak

Wearing facial masks has been indicated as an effective way to reduce the risk of COVID-19 transmission among people. To get a deeper understanding of the habit of using face masks in normal life during COVID-19 outbreak and seek ways to solve the problems of mask using, we conducted a large-scale survey in China through online questionnaires. Totally 1004 respondents, including community outreach workers, non-healthcare professionals, retired people, and students participated in this study. Detailed information regarding the types of masks that people usually use, the habit of changing masks, the methods of mask cleaning, and the attitude toward reusing masks and their potential impact on the environment were collected and analyzed. Results show that more than 98% of people in China used masks during the pandemic, and the types of masks using and frequency of masks changing/reuse varied between different people. Moreover, most of the respondents had a healthy mask-changing habit for preventing the spread of COVID-19 and worried about the safety of mask reusing. The study would help enhance public awareness and develop policies for a better habit in face of the pandemic.