Department of Urology, University of Washington School of Medicine, Seattle Children's Hospital, Seattle, Washington, United States.
Viral Special Pathogens Branch, Division of High Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States.
Infect Control Hosp Epidemiol. 2022 Jul;43(7):876-885. doi: 10.1017/ice.2021.230. Epub 2021 May 21.
The coronavirus disease 2019 (COVID-19) pandemic has resulted in shortages of personal protective equipment (PPE), underscoring the urgent need for simple, efficient, and inexpensive methods to decontaminate masks and respirators exposed to severe acute respiratory coronavirus virus 2 (SARS-CoV-2). We hypothesized that methylene blue (MB) photochemical treatment, which has various clinical applications, could decontaminate PPE contaminated with coronavirus.
The 2 arms of the study included (1) PPE inoculation with coronaviruses followed by MB with light (MBL) decontamination treatment and (2) PPE treatment with MBL for 5 cycles of decontamination to determine maintenance of PPE performance.
MBL treatment was used to inactivate coronaviruses on 3 N95 filtering facepiece respirator (FFR) and 2 medical mask models. We inoculated FFR and medical mask materials with 3 coronaviruses, including SARS-CoV-2, and we treated them with 10 µM MB and exposed them to 50,000 lux of white light or 12,500 lux of red light for 30 minutes. In parallel, integrity was assessed after 5 cycles of decontamination using multiple US and international test methods, and the process was compared with the FDA-authorized vaporized hydrogen peroxide plus ozone (VHP+O) decontamination method.
Overall, MBL robustly and consistently inactivated all 3 coronaviruses with 99.8% to >99.9% virus inactivation across all FFRs and medical masks tested. FFR and medical mask integrity was maintained after 5 cycles of MBL treatment, whereas 1 FFR model failed after 5 cycles of VHP+O.
MBL treatment decontaminated respirators and masks by inactivating 3 tested coronaviruses without compromising integrity through 5 cycles of decontamination. MBL decontamination is effective, is low cost, and does not require specialized equipment, making it applicable in low- to high-resource settings.
2019 年冠状病毒病（COVID-19）大流行导致个人防护设备（PPE）短缺，这突显了迫切需要简单、高效和廉价的方法来对暴露于严重急性呼吸冠状病毒 2（SARS-CoV-2）的口罩和呼吸器进行消毒。我们假设亚甲蓝（MB）光化学处理具有多种临床应用，可对被冠状病毒污染的 PPE 进行消毒。
该研究的 2 个臂包括（1）用冠状病毒接种 PPE，然后用光（MBL）进行消毒处理，（2）用 MBL 处理 PPE 5 个循环以确定 PPE 性能的维持。
使用 MBL 处理来灭活 3 个 N95 过滤式面罩（FFR）和 2 个医用口罩模型上的冠状病毒。我们用 3 种冠状病毒（包括 SARS-CoV-2）接种 FFR 和医用口罩材料，并用 10µM MB 处理，并将其暴露于 50,000 勒克斯的白光或 12,500 勒克斯的红光下 30 分钟。同时，使用多种美国和国际测试方法评估经过 5 个循环消毒后的完整性，并将该过程与经 FDA 授权的汽化过氧化氢加臭氧（VHP+O）消毒方法进行比较。
总体而言，MBL 以 99.8%至>99.9%的病毒灭活率在所有测试的 FFR 和医用口罩上均可靠且一致地灭活了所有 3 种冠状病毒。经过 5 个循环的 MBL 处理后，FFR 和医用口罩的完整性得以维持，而 1 个 FFR 模型在经过 5 个循环的 VHP+O 处理后失效。
MBL 处理通过灭活 3 种经测试的冠状病毒来对呼吸器和口罩进行消毒，而不会通过 5 个循环的消毒来损害完整性。MBL 消毒有效，成本低，且不需要专用设备，因此适用于低资源到高资源环境。
