Pilot study on burden of fungal contamination in face masks: need for better mask hygiene in the COVID-19 era.

Risk factors which led to the outbreak of COVID-19 associated Mucormycosis still remains elusive. Face masks can become contaminated by fungal spores that are present ubiquitously in the environment. However the exact burden of such contamination is not known. Fifty masks of patients who attended the Employees Health Scheme COVID-19 facility of a tertiary healthcare centre in India were sampled by direct impression smears on Sabouraud Dextrose Agar. Agar plates were screened for any growth within five days after incubation. Growth was identified by microscopy on the Lactophenol Cotton Blue mount. Mask hygiene practices of participants was assessed using a pre-designed proforma. Out of 50 masks, fungal contamination was seen in 35/50 (70%) masks, with Aspergillus sp. being isolated from 26/50 (52%) masks and Mucorales being isolated from 9/50 (18%) of the masks. Aspergillus niger, Rhizopus a rrhizus and Syncephalastrum sp. were the most common species isolated. Same mask was worn for a median duration of 8 days (2-30 days) at a stretch with or without washing. Thirty one patients washed and re-wore their masks, with median time duration since last wash being 12 hours (4-72 hours). None of the factors assessed for mask hygiene were associated with fungal contamination. High rates of fungal contamination observed in our study emphasizes the need for better mask hygiene in the COVID-19 era.