N95口罩能否在消毒后復(fù)用？翻譯一篇research letter
最近有不少朋友詢問口罩消毒的事情，于是我翻到了這篇2020年9月發(fā)表在Emerging Infectious Diseases上的research letter。由于它給出了結(jié)論和比較容易執(zhí)行的方案，遂搬運(yùn)。僅提供一種可能性，以應(yīng)對(duì)（可能發(fā)生的）N95短缺。一次性使用醫(yī)用口罩及醫(yī)用外科口罩請(qǐng)勿復(fù)用。
愿意啃論文的朋友，可以到https://www.zhihu.com/question/367683843?utm_id=0看看其他類似研究，其中有一篇指出常見消毒方法可能破壞熔噴材料結(jié)構(gòu)，但似乎與其他論文意見存在沖突。
我本人不是醫(yī)學(xué)/概率學(xué)/統(tǒng)計(jì)學(xué)專業(yè)，翻譯可能存在錯(cuò)誤，歡迎發(fā)現(xiàn)錯(cuò)誤的朋友們指出；也歡迎持有不同觀點(diǎn)的朋友帶著論據(jù)來交流。
請(qǐng)注意，這篇letter只測(cè)試了消毒方法生效時(shí)長(zhǎng)和對(duì)N95口罩熔噴材料過濾性能的影響，沒有測(cè)試對(duì)呼氣閥、鼻梁條、頭帶等其他附件的影響。建議每次消毒后做一次定性的適合性試驗(yàn)以確保N95口罩功能的完整性！
有論文用市面上能隨便買到的工具“教你在家做定性適合性試驗(yàn)（QLFT）”，生肉，我正在搬。能者先啃：https://doi.org/10.1017/dmp.2020.352
術(shù)語首次出現(xiàn)時(shí)會(huì)用括號(hào)寫出縮寫，再出現(xiàn)會(huì)直接用縮寫（懶）；譯文中由譯者添加的括號(hào)是方括號(hào)，在原文中就有的括號(hào)是圓括號(hào)。
以下是全文搬運(yùn)+正文翻譯：
對(duì)N95呼吸器消毒的有效性，及應(yīng)對(duì)新冠病毒的復(fù)用
Effectiveness of N95 Respirator Decontamination and Reuse against SARS-CoV-2 Virus
Robert J. Fischer, Dylan H. Morris, Neeltje van Doremalen, Shanda Sarchette, M. Jeremiah Matson, Trenton Bushmaker, Claude Kwe Yinda, Stephanie N. Seifert, Amandine Gamble, Brandi N. Williamson, Seth D. Judson, Emmie de Wit, James O. Lloyd-Smith, Vincent J. Munste
DOI: https://doi.org/10.3201/eid2609.201524
摘要：冠狀病毒疫情大流行引起了全球范圍的N95呼吸器短缺。我們選用了四種消毒方法，分析了它們對(duì)新冠病毒的滅活能力和對(duì)呼吸器功能的影響。結(jié)果指出，N95呼吸器可以在消毒后復(fù)用，前提是呼吸器的適合性及氣密性保持完好。
The coronavirus pandemic has created worldwide shortages of N95 respirators. We analyzed 4 decontamination methods for effectiveness in deactivating severe acute respiratory syndrome coronavirus 2 virus and effect on respirator function. Our results indicate that N95 respirators can be decontaminated and reused, but the integrity of respirator fit and seal must be maintained.
史無前例的冠狀病毒病大流行造成了世界范圍內(nèi)個(gè)人防護(hù)用品【personal protective equipment，PPE】的短缺，尤其是如N95呼吸器這類的呼吸系統(tǒng)防護(hù)用具(1)。新冠病毒在醫(yī)院環(huán)境的傳播時(shí)有發(fā)生，大量院內(nèi)傳播案例凸顯出醫(yī)護(hù)工作者【面對(duì)院感】的脆弱性(2)。新冠病毒在環(huán)境中的穩(wěn)定性【environmental stability】造成了對(duì)迅速、有效的消毒方法的迫切需求。
The unprecedented pandemic of coronavirus disease has created worldwide shortages of personal protective equipment, in particular respiratory protection such as N95 respirators (1). Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurs frequently in hospital settings; numerous reported cases of nosocomial transmission highlight the vulnerability of healthcare workers (2). The environmental stability of SARS-CoV-2 virus underscores the need for rapid and effective decontamination methods.
一般來說，N95呼吸器本該在使用一次后即丟棄，不過大量文獻(xiàn)中都包含對(duì)N95呼吸器消毒以殺滅細(xì)菌芽孢【bacterial spores】、細(xì)菌或呼吸道病毒（比如甲流病毒）(3-6)的內(nèi)容。有效殺滅病原體的方法包括紫外線、環(huán)氧乙烷、汽化雙氧水【vaporized hydrogen peroxide，VHP】、γ射線、臭氧和干熱(A. Cramer et al., unpub data, https://doi.org/10.1101/2020.03.28.20043471) (3–6)。然而，針對(duì)這些消毒方法對(duì)N95呼吸器的過濾效率及適合性的影響，尚未有太多深入研究。有報(bào)告顯示，上述的消毒方法確實(shí)會(huì)對(duì)N95呼吸器的過濾效率和適合性產(chǎn)生影響。(7; 附錄：https://wwwnc.cdc.gov/EID/ article/26/9/20-1524-App1.pdf).
In general, N95 respirators are designed for one use before disposal. Extensive literature is available for decontaminating N95 respirators of either bacterial spores, bacteria, or respiratory viruses (e.g. influenza A virus) (3–6). Effective inactivation methods for these pathogens and surrogates include UV light, ethylene oxide, vaporized hydrogen peroxide (VHP), gamma irradiation, ozone, and dry heat (A. Cramer et al., unpub data, https://doi.org/10.1101/2020.03.28.20043471) (3–6). The filtration efficiency and fit of N95 respirators has been less well explored, but reports suggest that both filtration efficiency and N95 respirator fit can be affected by the decontamination method used (7; Appendix, https://wwwnc.cdc.gov/EID/ article/26/9/20-1524-App1.pdf).
我們選用了4種消毒方法——紫外線（波長(zhǎng)260-285納米）、70℃干熱、70%酒精和汽化雙氧水【VHP】，分析了它們殺滅新冠病毒的能力和對(duì)N95呼吸器功能的影響。新冠病毒初始接種的循環(huán)閾值【Ct值】*為20-22，接近從人的上呼吸道及下呼吸道取樣得來的數(shù)值。我們將每一種消毒方法在N95織物【N95 filter fabric】上的消毒速率，同該消毒方法在不銹鋼上的消毒速率作比較。在每一輪消毒并佩戴兩小時(shí)后，我們采用定量的適合性試驗(yàn)【QNFT】評(píng)估N95呼吸器的過濾效果，連續(xù)做三輪(附錄)。VHP和酒精在N95及不銹鋼上都有極快的消毒速率（圖，panel A）；紫外線在不銹鋼上的消毒速率很快，但在N95織物上慢得多，推測(cè)與織物多孔的特性有關(guān)；干熱則相反，在N95上的消毒速率比在不銹鋼上快。
（*譯者：記得核酸檢測(cè)的“Ct值”嗎？就是它）
We analyzed 4 different decontamination methods, UV light (260–285 nm), 70oC dry heat, 70% ethanol, and VHP, for their ability to reduce contamination with infectious SARS-CoV-2 and their effect on N95 respirator function. The starting inoculum of SARS-CoV-2 has cycle threshold values of 20–22, similar to those observed in samples obtained from the upper and lower respiratory tract in humans. For each of the decontamination methods, we compared the normal inactivation rate of SARS-CoV-2 virus on N95 filter fabric to that on stainless steel. Using quantitative fit testing, we measured the filtration performance of N95 respirators after each decontamination run and 2 hours of wear, for 3 consecutive decontamination and wear sessions (Appendix). VHP and ethanol yielded extremely rapid inactivation both on N95 and on stainless steel (Figure, panel A). UV light inactivated SARS-CoV-2 virus rapidly from steel but more slowly on N95 fabric, probable because of its porous nature. Heat caused more rapid inactivation on N95 than on steel; inactivation rates on N95 were comparable to UV.
圖。4種方式消毒N95呼吸器的結(jié)果。
A) 新冠病毒失活速率（附錄：https://wwwnc.cdc.gov/EID/article/26/9/20-1524-App1.pdf）?！包c(diǎn)”是三次消毒后平均存活滴度【mean viable titer】的估計(jì)值，“圓”是平均存活滴度的后驗(yàn)中值，“粗條”是68% credible interval【這怎么翻？】，“細(xì)條”是95% credible interval。直線表示病毒滴度隨時(shí)間衰減的程度，根據(jù)指數(shù)衰減曲線（負(fù)斜率）的聯(lián)合后驗(yàn)分布和截距（初始病毒滴度），隨機(jī)重復(fù)50次后生成。任意一次試驗(yàn)中未出現(xiàn)陽(yáng)性孔的用三角形標(biāo)記在每次試驗(yàn)近似檢出限【approximate single-replicate LOD】上，用來指示低于檢出限【LOD】的值可能置于的區(qū)間。黑色點(diǎn)虛線表示近似檢出限：100.5 TCID50/mL。在酒精和干熱針對(duì)不銹鋼消毒的圖中，為了避免過度繪制，t=0時(shí)在LOD上的點(diǎn)有輕微向上和向左移動(dòng)。
B）消毒并佩戴兩小時(shí)，重復(fù)三輪后，口罩的QNFT結(jié)果。每種消毒方法的6次實(shí)驗(yàn)的數(shù)據(jù)（小圓和小三角），以及估計(jì)的適合因數(shù)中值（大圓）、適合因數(shù)的68%區(qū)間（粗條）、95%區(qū)間（細(xì)條）如圖所示。適合因數(shù)是口罩外顆粒物濃度與口罩內(nèi)濃度的比值，用于衡量過濾能力，由測(cè)量的機(jī)器報(bào)出數(shù)值。
（譯者：如果你看翻譯看得頭大，請(qǐng)相信我，我看原文也是這種感覺。）
Figure. Results of decontamination of N95 respirators by 4 different methods. A) Inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus (Appendix, https://wwwnc.cdc.gov/EID/article/26/9/20-1524-App1.pdf). Points indicate estimated mean viable titer across 3 replicates, circles the posterior median estimate of the mean, thick bars a 68% credible interval, and thin bars a 95% credible interval. Lines show predicted decay of virus titer over time and were generated by 50 random draws/replicate from the joint posterior distribution of the exponential decay rate (negative of the slope) and intercept (initial virus titer). Time points with no positive wells for any replicate are plotted as triangles at the approximate single-replicate LOD to indicate a plausible range of sub-LOD values. Black dotted line shows approximate LOD: 100.5 TCID50/mL media. Points at the LOD and at t = 0 for ethanol and heat methods applied to steel are offset slightly up and to the left to avoid overplotting. B) Mask integrity quantitative fit testing results after decontamination and 2 hours of wear for 3 consecutive runs. Data from 6 individual replicates (small circles and triangles) for each treatment are shown, in addition to estimated median fit factor (large circles), 68% range of underlying fit factors (thick bars), and 95% range (thin bars). Fit factors are a measure of filtration performance, the ratio of the concentration of particles outside the mask to the concentration inside. The measurement machine reports values
QNFT顯示：4種消毒方法的單輪消毒都不會(huì)顯著降低N95呼吸器的過濾能力*（圖，panel B），而后續(xù)的消毒中，酒精和干熱會(huì)大幅降低N95的過濾能力，其中干熱的表現(xiàn)略好于酒精。經(jīng)VHP和紫外線消毒的口罩相較于對(duì)照組，在兩輪消毒后仍保持著差不多【comparable】的過濾能力，三輪消毒后的表現(xiàn)“勉強(qiáng)能用”【acceptable】。
（*譯者：仍有下降，酒精和干熱消毒后的N95有小概率通不過適合性試驗(yàn)，見圖）
Quantitative fit tests showed that the filtration performance of the N95 respirator was not markedly reduced after a single decontamination for any of the 4 decontamination methods (Figure, panel B). Subsequent rounds of decontamination caused sharp drops in filtration performance of the ethanol-treated masks and, to a slightly lesser degree, the heat-treated masks. The VHP- and UV-treated masks retained comparable filtration performance to the control group after 2 rounds of decontamination and maintained acceptable performance after 3 rounds.
我們發(fā)現(xiàn)，VHP消毒既能在短時(shí)間內(nèi)使新冠病毒失活，又能較好地保持N95呼吸器功能完整性（在實(shí)驗(yàn)室條件下），綜合來看是最佳選擇；紫外線在保持功能完整性方面的表現(xiàn)與VHP幾乎一樣好，但消毒速度要慢得多；70℃的干熱與紫外線的消毒速度相似，也能讓N95在一至兩輪輪消毒后仍保持可接受的【acceptable】適合性，但不應(yīng)超過三輪；與過往的結(jié)論(8)一致，酒精消毒會(huì)破壞N95功能完整性，并不推薦。
Our findings showed that VHP treatment had the best combination of rapid inactivation of SARS-CoV-2 virus and preservation of N95 respirator integrity under the experimental conditions (Figure, panel C). UV light killed the virus more slowly and preserved respirator function almost as well. Dry heat at 70oC killed the virus with similar speed to UV and is likely to maintain acceptable fit scores for 1–2 rounds of decontamination but should not be used for 3 rounds. Consistent with earlier findings (8), ethanol decontamination reduced N95 integrity and is not recommended.
上述的所有消毒方法——尤其是紫外線和干熱，在使用時(shí)都應(yīng)有足夠長(zhǎng)的消毒時(shí)間來保證有效降低病毒濃度，具體需要的時(shí)間取決于初始的病毒污染程度。決策者可以用我們估計(jì)出的【病毒濃度】衰減曲線，結(jié)合實(shí)際估計(jì)的污染程度，來選擇合適的處置時(shí)長(zhǎng)（附錄）。
All treatments, particularly UV light and dry heat, should be conducted for long enough to ensure sufficient reduction in virus concentration. The degree of required reduction depends upon the degree of initial virus contamination. Policymakers can use our estimated decay rates together with estimates of real-world contamination to choose appropriate treatment durations (Appendix).
?
?
我們的結(jié)果指出，在N95呼吸器短缺的時(shí)期，可以使用紫外線和VHP對(duì)其進(jìn)行最多三次的消毒，或用干熱進(jìn)行一至兩次的消毒。在此期間，請(qǐng)務(wù)必遵循國(guó)家制定的關(guān)于適合性試驗(yàn)、氣密性檢查和呼吸器復(fù)用的指南【guidelines】。我們建議每次消毒的時(shí)長(zhǎng)要足，并在每次消毒后，利用現(xiàn)有的定性的適合性試驗(yàn)【QLFT】工具，確保呼吸器的功能完好。
Our results indicate that, in times of shortage, N95 respirators can be decontaminated and reused up to 3 times by using UV light and HPV and 1–2 times by using dry heat. Following nationally established guidelines for fit testing, seal check, and respirator reuse is critical (9,10). We recommend performing decontamination for sufficient time and ensuring proper function of the respirators after decontamination using readily available qualitative fit testing tools.
致謝（不翻了）
Acknowledgments
We thank Madison Hebner, Julia Port, Kimberly Meade-White, Irene Offei Owusu, Victoria Avanzato, and Lizzette Perez-Perez for excellent technical assistance.
This research was supported by the Intramural Research Program of the National Institute of Allergy and Infectious Diseases, National Institutes of Health. J.O.L.-S. and A.G. were supported by the Defense Advanced Research Projects Agency PREEMPT no. D18AC00031 and the UCLA AIDS Institute and Charity Treks, and J.O.L.-S. was supported by the US National Science Foundation (DEB-1557022), the Strategic Environmental Research and Development Program (RC‐2635) of the US Department of Defense.
關(guān)于作者（不翻了）
About the Author
Dr. Fischer is a member of the Virus Ecology Section at the Rocky Mountain Laboratories Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health. His research interests include the ecology of emerging viruses in their natural and spillover hosts, including SARS-CoV-2.
參考文獻(xiàn)
References
Ranney ML, Griffeth V, Jha AK. Critical supply shortages — the need for ventilators and personal protective equipment during the Covid-19 pandemic. N Engl J Med. 2020;382:e41. https://doi.org/10.1056/NEJMp2006141
McMichael TM, Currie DW, Clark S, Pogosjans S, Kay M, Schwartz NG, et al. Epidemiology of Covid-19 in a long-term care facility in King County, Washington. N Engl J Med. 2020; NEJMoa2005412. https://doi.org/10.1056/NEJMoa2005412
Batelle. Final report for the Bioquell hydrogen peroxide vapor (HPV) decontamination for reuse of N95 respirators. 2016 [cited 2020 May 22]. https://www.fda.gov/media/ 136386/download
Fisher EM, Shaffer RE. A method to determine the available UV-C dose for the decontamination of filtering facepiece respirators. J Appl Microbiol. 2011;110:287–95. https://doi.org/10.1111/j.1365-2672.2010.04881.x
Heimbuch BK, Wallace WH, Kinney K, Lumley AE, Wu CY, Woo MH, et al. A pandemic influenza preparedness study: use of energetic methods to decontaminate filtering facepiece respirators contaminated with H1N1 aerosols and droplets. Am J Infect Control. 2011;39:e1–9. https://doi.org/10.1016/ j.ajic.2010.07.004
Lin TH, Tang FC, Hung PC, Hua ZC, Lai CY. Relative survival of Bacillus subtilis spores loaded on filtering facepiece respirators after five decontamination methods. Indoor Air. 2018;28:754–62. https://doi.org/10.1111/ina.12475
Lin TH, Chen CC, Huang SH, Kuo CW, Lai CY, Lin WY. Filter quality of electret masks in filtering 14.6–594 nm aerosol particles: effects of five decontamination methods. PLoS One. 2017; 12:e0186217. https://doi.org/10.1371/journal.pone.0186217
Viscusi DJ, Bergman MS, Eimer BC, Shaffer RE. Evaluation of five decontamination methods for filtering facepiece respirators. Ann Occup Hyg. 2009;53:815–827. https://doi.org/10.1093/annhyg/mep070
US Centers for Disease Control and Prevention. Decontamination and reuse of filtering facepiece respirators. 2020 [cited 2020 Apr 5]. https://www.cdc.gov/coronavirus/2019-ncov/ hcp/ppe-strategy/decontamination-reuse-respirators.html
US National Institute for Occupational Safety and Health; US Centers for Disease Control and Prevention. Recommended guidance for extended use and limited reuse of N95 filtering facepiece respirators in healthcare settings. 2020 [cited 2020 May 22]. https://www.cdc.gov/niosh/topics/hcwcontrols/ recommendedguidanceextuse.html
