Microbiological Contamination of Reusable Cloth Face Masks Among Market Traders in Kano, Kano State

The adoption of reusable cloth face masks as a respiratory protection measure during infectious disease outbreaks has raised important questions about the microbial safety of improperly maintained masks. This study evaluated microbiological contamination of reusable cloth face masks worn by traders in Kano central market, Kano State, North West Nigeria. Mask samples were collected from 60 consenting traders, half of whom reported daily mask washing and half with infrequent washing (less than once per week). Inner and outer surfaces of each mask were sampled using sterile swabs moistened with 0.9 percent saline. Total aerobic plate counts, fungal counts, and identification of S. aureus, Klebsiella species, and Aspergillus species were performed. Results showed that traders who washed masks infrequently had mean bacterial counts on inner surfaces that were 8-fold higher than those who washed daily. S. aureus was isolated from 58 percent of infrequently washed masks compared to 15 percent of daily-washed masks. Aspergillus flavus was isolated from 25 percent of infrequently washed masks. Multiple layers and synthetic fabric composition were associated with higher microbial retention. These findings suggest that without proper hygiene, reusable masks may paradoxically expose wearers to elevated microbial loads. Public health messaging on mask hygiene practices should be prioritized in high-density market environments. Keywords: cloth face masks, microbial contamination, Staphylococcus aureus, hand hygiene, Kano.