Kitagawa Hiroki, Nomura Toshihito, Nazmul Tanuza, Kawano Reo, Omori Keitaro, Shigemoto Norifumi, Sakaguchi Takemasa, Ohge Hiroki
Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan; Project Research Center for Nosocomial Infectious Diseases, Hiroshima University, Hiroshima, Japan; Department of Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Department of Infectious Diseases, Hiroshima University Hospital, Hiroshima, Japan; Department of Virology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Photodiagnosis Photodyn Ther. 2021 Mar;33:102184. doi: 10.1016/j.pdpdt.2021.102184. Epub 2021 Jan 20.
The effectiveness of 222 nm ultraviolet (UV) C light for disinfecting surfaces contaminated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been reported. The aim of this study was to evaluate the effect of the intermittent irradiation of 222 nm UVC on SARS-CoV-2 and the fluence-dependent effect of 222 nm UVC irradiation on SARS-CoV-2 inactivation.
We experimented with 5 min continuous and intermittent irradiation for 0.1, 0.05, 0.013, and 0.003 mW/cm of 222 nm UVC to evaluate the differences in the effect of the continuous and intermittent irradiation of 222 nm UVC on SARS-CoV-2 inactivation. For intermittent irradiation, we followed the on-off irradiation cycles with every 10-s irradiation followed by a 380-s interval. Thereafter, we evaluated the effects of 0.1, 0.013, and 0.003 mW/cm 222 nm UVC irradiation on SARS-CoV-2 contamination at UV fluences of 1, 2, and 3 mJ/cm at each irradiance.
At each irradiance, no significant difference was observed in the log reduction of SARS-CoV-2 between continuous and intermittent irradiation. At each UV fluence, no significant difference was observed in the log reduction of SARS-CoV-2 among the three different irradiance levels.
There was no significant difference between continuous and intermittent irradiation with 222 nm UVC with regards to SARS-CoV-2 inactivation. Moreover, 222 nm UVC inactivates SARS-CoV-2 in a fluence-dependent manner. The efficacy of 222-nm UVC irradiation in reducing the contamination of SARS-CoV-2 needs to be further evaluated in a real-world setting.
已有报道称222纳米深紫外线（UVC）光对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）污染的表面具有消毒效果。本研究的目的是评估222纳米UVC间歇照射对SARS-CoV-2的影响以及222纳米UVC照射对SARS-CoV-2灭活的光通量依赖性影响。
我们用222纳米UVC以0.1、0.05、0.013和0.003毫瓦/平方厘米进行5分钟连续和间歇照射，以评估222纳米UVC连续和间歇照射对SARS-CoV-2灭活效果的差异。对于间歇照射，我们采用开-关照射循环，每次照射10秒，随后间隔380秒。此后，我们评估了在每个辐照度下，0.1、0.013和0.003毫瓦/平方厘米的222纳米UVC照射在1、2和3毫焦/平方厘米的紫外线光通量下对SARS-CoV-2污染的影响。
在每个辐照度下，连续照射和间歇照射之间SARS-CoV-2的对数减少量没有显著差异。在每个紫外线光通量下，三种不同辐照度水平之间SARS-CoV-2的对数减少量没有显著差异。
在SARS-CoV-2灭活方面，222纳米UVC连续照射和间歇照射之间没有显著差异。此外，222纳米UVC以光通量依赖性方式使SARS-CoV-2失活。222纳米UVC照射在减少SARS-CoV-2污染方面的效果需要在实际环境中进一步评估。
