Unisanté, Department of Occupational and Environmental Health, University of Lausanne, Lausanne, Switzerland
Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland.
BMJ Glob Health. 2020 Oct;5(10). doi: 10.1136/bmjgh-2020-003110.
During pandemics, such as the SARS-CoV-2, filtering facepiece respirators plays an essential role in protecting healthcare personnel. The recycling of respirators is possible in case of critical shortage, but it raises the question of the effectiveness of decontamination as well as the performance of the reused respirators.
Disposable respirators were subjected to ultraviolet germicidal irradiation (UVGI) treatment at single or successive doses of 60 mJ/cm after a short drying cycle (30 min, 70°C). The germicidal efficacy of this treatment was tested by spiking respirators with two staphylococcal bacteriophages (vB_HSa_2002 and P66 phages). The respirator performance was investigated by the following parameters: particle penetration (NaCl aerosol, 10-300 nm), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry and mechanical tensile tests.
No viable phage particles were recovered from any of the respirators after decontamination (log reduction in virus titre >3), and no reduction in chemical or physical properties (SEM, particle penetrations <5%-6%) were observed. Increasing the UVGI dose 10-fold led to chemical alterations of the respirator filtration media (FTIR) but did not affect the physical properties (particle penetration), which was unaltered even at 3000 mJ/cm (50 cycles). When respirators had been used by healthcare workers and undergone decontamination, they had particle penetration significantly greater than never donned respirators.
This decontamination procedure is an attractive method for respirators in case of shortages during a SARS pandemic. A successful implementation requires a careful design and particle penetration performance control tests over the successive reuse cycles.
在 SARS-CoV-2 等大流行期间，过滤式面罩呼吸器在保护医护人员方面发挥着重要作用。在严重短缺的情况下，呼吸器可以回收再利用，但这引发了消毒效果以及重复使用的呼吸器性能的问题。
一次性呼吸器在经过 30 分钟、70°C 的短暂干燥循环后，接受单次或连续 60 mJ/cm 的紫外线杀菌照射（UVGI）处理。通过将两种葡萄球菌噬菌体（vB_HSa_2002 和 P66 噬菌体）接种到呼吸器上来测试这种处理的杀菌效果。通过以下参数研究呼吸器的性能：颗粒渗透（NaCl 气溶胶，10-300nm）、扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）、差示扫描量热法和机械拉伸试验。
经过消毒后，没有从任何呼吸器中回收活噬菌体颗粒（病毒滴度对数减少>3），并且没有观察到化学或物理性质的降低（SEM，颗粒渗透<5%-6%）。将 UVGI 剂量增加 10 倍导致呼吸器过滤介质的化学性质发生变化（FTIR），但不影响物理性质（颗粒渗透），即使在 3000 mJ/cm（50 次循环）时也未改变。当呼吸器被医护人员使用并经过消毒后，它们的颗粒渗透显著大于从未佩戴过的呼吸器。
在 SARS 大流行期间，短缺情况下，这种消毒程序是一种有吸引力的呼吸器处理方法。成功实施需要对连续重复使用循环进行仔细的设计和颗粒渗透性能控制测试。
