安全、便捷技术再生一次性医用口罩的实验研究

在防控新型冠状病毒(2019 novel coronavirus, 2019-nCoV)疫情中，为了减少病毒的传播，一次性医用口罩是普通民众必不可缺少的防护品。然而，随着2019-nCoV的蔓延，口罩短缺现象严重。本研究旨在探讨一次性医用外科口罩(口罩)的再生方法，以达到既有个人防护的效果又能节省资源。用流行性感冒病毒(简称流感)模拟2019-nCoV污染口罩，采用常用的恒温烘箱干烤及电吹风机热风处理2种方法，对表面污染有流感病毒的医用口罩进行病毒灭活，洗脱口罩上已灭活处理的病毒，感染Mardin-Darby狗肾细胞(Mardin-Darby canine kidney cell，MDCK细胞)，观察细胞病变并定量检测病毒基因组拷贝数以评价病毒灭活效果。同时采用抽滤系统和PM2.5监测仪对以2种相似热灭活方式处理过的口罩滤过截留PM2.5的效果进行评价。结果显示电吹风机30 min热风处理后病毒基因组拷贝数降低至原来的1/1 000 000～1/10 000 000，接近未感染组，但烘箱56 ℃ 30 min干热处理仅灭活部分病毒。2种热灭活方式对口罩的PM2.5滤过截留效果无显著影响。本研究提供了一个安全、便捷处理一次性医用外科口罩的方法，为个人防护用品口罩表面污染病毒的灭活及其再生利用提供了科学依据。然而，应注意的是在口罩匮乏的非常时期，普通人群可采用该简便技术再生口罩后再次使用，但该方法再生的口罩不适合密切接触患者的人群、医护人员及实验室工作人员使用。

Evaluation of heat inactivation of virus contamination on medical mask

The outbreak of the 2019 Novel Coronavirus(2019-nCoV)in Wuhan and its continuous spread to almost all the area of China created an urgent need for personal protective equipment(PPE).Heat inactivating contaminated pathogens on the surface of PPE may provide a possible way to re-use PPE and alleviate the great burden of needs of PPE.We assessed the effect of heating inactivation of influenza virus on medical masks by baking and hair dryer.We also assessed mask filterability to PM2.5 after similar heating processes.Efficiency of viral inactivation was evaluated by infecting MDCK cells with the rescued virus and quantifying the viral RNA levels in the supernatants produced by the infected cells.Using theair dryer for 30 minutes effectively inactivated virus whereas baking at 56℃for 30 min partially inactivated virus.Both hair dryer and baking did not significantly affect the mask filterability to ambient PM2.5.Although the results indicated that in the period that masks are insufficient for whole population,the community people can use this simple technique to regenerate masks for reuse,it is important to note that this method is not suitable for people who are in close contact with patients,medical staffs and laboratory technicians.