Exploring inactivation of SARS-CoV-2, MERS-CoV, Ebola, Lassa, and Nipah viruses on N95 and KN95 respirator material using photoactivated methylene blue to enable reuse

Background: The COVID-19 pandemic resulted in a worldwide shortage of N95 respirators, prompting the devel-opment of decontamination methods to enable limited reuse. Countries lacking reliable supply chains would also benefit from the ability to safely reuse PPE. Methylene blue (MB) is a light-activated dye with demonstrated anti-microbial activity used to sterilize blood plasma. Decontamination of respirators using photoactivated MB requires no specialized equipment, making it attractive for use in the field during outbreaks.Methods: We examined decontamination of N95 and KN95 respirators using photoactivated MB and 3 var-iants of SARS-CoV-2, the virus that causes COVID-19; and 4 World Health Organization priority pathogens: Ebola virus, Middle East respiratory syndrome coronavirus, Nipah virus, and Lassa virus. Virus inactivation by pretreating respirator material was also tested.Results: Photoactivated MB inactivated all tested viruses on respirator material, albeit with varying effi-ciency. Virus applied to respirator material pre-treated with MB was also inactivated, thus MB pretreatment may potentially protect respirator wearers from virus exposure in real-time.Conclusions: These results demonstrate that photoactivated MB represents a cost-effective, rapid, and widely deployable method to decontaminate N95 respirators for reuse during supply shortages.(c) 2022 Published by Elsevier Inc. on behalf of Association for Professionals in Infection Control and Epidemiology, Inc.

Automated summary

Researchers demonstrated that photoactivated methylene blue is a cost-effective, rapid, and widely deployable method to decontaminate N95 respirators for reuse during supply shortages.