Efficacy of anti-microbial gel vapours against aerosolised coronavirus, bacteria, and fungi

Background: The urban population spends up to 90% of their time indoors. The indoor environment harbours a diverse microbial population including viruses, bacteria, and fungi. Pathogens present in the indoor environment can be transmitted to humans through aerosols. Aim: This study evaluated the efficacy of an antimicrobial gel containing a mix of essential oils against aerosols of bacteria, fungi, and coronavirus. Methods: The antimicrobial gel was allowed to vapourize inside a glass chamber for 10 or 20 minutes. Microbial aerosols of Escerichia coli, Aspergillus flavus spores or murine hepatitis virus MHV 1, a surrogate of SARS CoV-2 was passed through the gel vapours and then collected on a 6-stage Andersen sampler. The number of viable microbes present in the aerosols collected in the different stages were enumerated and compared to number of viable microbes in control microbial aerosols that were not exposed to the gel vapours. Results: Vaporizing the antimicrobial gel for 10 and 20 minutes resulted in a 48% (p = 0.002 Vs. control) and 53% (p = 0.001 Vs. control) reduction in the number of MHV-1 in the aerosols, respectively. The antimicrobial gel vaporised for 10 minutes, reduced the number of viable E. coli by 51% (p = 0.032 Vs. control) and Aspergillus flavus spores by 72% (p=0.008 Vs. control) in the aerosols. Conclusions: The antimicrobial gel may be able to reduce aerosol transmission of microbes. Keywords: Aerosol, Coronavirus, SARS-CoV-2, Indoor Air, Antimicrobial, Essential oils