Detection of SARS-CoV-2 in Used Face Masks of Health-care Workers during an Intrapandemic Period of COVID-19

Dear Editor, The world has witnessed multiple waves of the SARS-CoV-2 pandemic despite implementing mandatory face masking. Inappropriate usage of masks may increase the transmission of COVID-19 infection. During normal breathing, the microbial population that gets inhaled through the nostrils may be exhaled as a result of immediate exhalation. However, consistent usage of masks leads to the gathering of the microbial population inside the surface area of the masks for a longer period, which may result in the inhalation of the viral particles inside unknowingly. Considering the applicability of face masks in reducing SARS-CoV-2 infection, the present article investigated the effect of face masking among health-care workers during the COVID-19 pandemic. During the study, used face masks (N-95 masks and surgical masks) of 231 health-care workers including clinicians, nurses, ward boys, and ward girls who were on duty at the COVID-19 intensive care unit and COVID-19 ward were collected from September to October 2021. Swab samples were taken from the inner and outer parts of the respective masks and extracted RNA samples from the masks were analyzed for SARS-CoV-2 positivity using a real-time polymerase chain reaction platform. Of the collected samples, six samples were positive for SARS-CoV-2 with a positive test rate of 2.59% (cycle threshold [CT] values ranged from 25 to 34). It is noteworthy to mention that, 2/6 samples, taken from the inner part of the N-95 masks were positive for the SARS-CoV-2 genes (E and ORF). However, the followed up samples from these two individuals were negative for SARS-CoV-2. The other four participants whose outer part of the used face masks tested SARS-CoV-2 positive could not be followed up considering their refusal to participate in the study. The main contention of the study was to investigate whether the inner or outer surfaces of the face masks were carrying the virus unknowingly thereby increasing the risk of more transmissions among healthy individuals. Our data thus prompted that during September–October 2021, when the overall infection rate in the region was below 2%, SARS-CoV-2 was detected in the face masks. Comparing this with the crucial period when the infection rate was quite high worldwide, the possibility of face masks acting as fomites for the healthy population cannot be ruled out. Several studies have been conducted focusing on the role and applicability of face masks in reducing COVID-19 infection including a randomized trial from Bangladesh with 3,42,183 participants.[1-3] In a previous study, it was documented that the countries with high levels of face masking among people did not show better outcomes than the countries with low mask usage during the six months of the second wave of SARS-CoV-2 in Europe.[4] Interestingly, the COVID-19 management policy in Sweden was mainly featured in the development of “natural” herd immunity by avoiding a societal shutdown and and mandatory masking.[5] The present article hinted at the possibility of face masks acting as fomites for the healthy population. The study, thus, prompted the point that improper use of face masks by the healthy population including health-care workers may unknowingly trigger the increased infection which may contribute to future COVID-19 waves. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.