Covid-19: How long does the coronavirus last on surfaces?[1]
新冠病毒(COVID-19)能在物體表面上存留多久？
We can pick up the Covid-19 by touching surfaces contaminated with the new coronavirus, but it is only just becoming clear how long the virus can survive outside the human body.
接觸到沾有新冠病毒的物體表面可能會染上武漢肺炎(Covid-19)，不過也漸漸有研究顯示這種病毒可以在人體外存活多長的時間。
By Richard Gray
17th March 2020
理查德·格雷（Richard Gray）於2020年3月17日發表
As Covid-19 has spread, so has our fear of surfaces. There are now some familiar scenes in public places around the world – people trying to open doors with their elbows, commuters studiously surfing their way through train journeys to avoid grabbing a handle, office workers rubbing down their desks each morning.
隨著新冠病毒的散播，我們對各種物體表面的恐懼也隨之蔓延。目前在世界各地的公共場所都能看到某些相似的畫面，例如有人會想用手肘開門、通勤者搭火車時身體會擺出像要衝浪的樣子，盡可能地保持平衡，也不願意用手握手把、坐辦公室的則會每天早上勤奮地擦桌子。
In the areas worst hit by the new coronavirus, teams of workers in protective clothing have been dispatched to spray a fog of disinfectant in plazas, parks and public streets. Cleaning regimes in offices, hospitals, shops and restaurants have been increased. In some cities, well-meaning volunteers even venture out at night to scrub the keypads of cash machines.
在新冠病毒疫情嚴重的地區，則會派出身穿防護服的工作人員到各個廣場、公園和街道上噴灑消毒劑。各地都在加強辦公室、醫院、商店和餐廳的清潔衛生。在某些城市，甚至有好心人冒著大半夜的危險擦洗自動提款機的鍵盤。
Like many respiratory viruses, including flu, Covid-19 can be spread in tiny droplets released from the nose and mouth of an infected person as they cough. A single cough can produce up to 3,000 droplets. These particles can land on other people, clothing and surfaces around them, but some of the smaller particles can remain in the air. There is also some evidence that the virus is also shed for longer in faecal matter, so anyone not washing their hands thoroughly after visiting the toilet could contaminate anything they touch.
和許多呼吸道病毒（包括流感）一樣，新冠病毒也能藉由感染者咳嗽時從鼻子和嘴裡噴出的微小飛沫中傳播。每次咳嗽最多可以產生3000滴飛沫。這些顆粒會附著在其他人的身上、衣服和周圍的物體表面上，而有些更小的顆粒則能停留在空氣中。還有一些證據顯示，這種病毒在糞便中能存活更長的時間，所以在上廁所後沒有徹底洗乾淨手的人都可能會污染他們接觸到的任何東西。
It is worth noting that, according to the Centers for Disease Control and Prevention, touching a surface or object with the virus and then touching one's own face "is not thought to be the main way the virus spreads". Even so, the CDC, the World Health Organization and others health authorities, have emphasised that both washing one's hands and cleaning and disinfecting frequently touched surfaces daily are key in preventing Covid-19's spread. So although we still don't know exactly how many cases are being caused directly by contaminated surfaces, experts advise exercising caution.
值得注意的是，據美國疾病控制與預防中心(CDC)所稱，接觸到沾染上病毒的表面或物體後，再碰到自己的臉，「並不是這種病毒主要的傳播方式」。即便如此，美國疾病控制與預防中心、世界衛生組織(WHO)和其他衛生機構也強調，每天勤洗手和消毒常被觸摸的物體表面都是防止病毒傳播的關鍵。因此，儘管我們仍然不清楚直接接觸到沾有病毒的物體表面而受到感染的案例到底有多少起，但是專家們仍然建議應謹慎防疫。
One aspect that has been unclear is exactly how long Sars-CoV-2, the name of the virus that causes the disease Covid-19, can survive outside the human body. Some studies on other coronaviruses, including Sars and Mers, found they can survive on metal, glass and plastic for as long as nine days, unless they are properly disinfected. Some can even hang around for up to 28 days in low temperatures.
目前尚不清楚的是Sars-CoV-2（導致武漢肺炎的病毒名稱）可以在人體外存活多長的時間。一些對其他冠狀病毒（包括SARS和MERS）的研究發現，若沒有進行適當的消毒，它們可以在金屬、玻璃和塑膠上存活長達9天的時間。有些病毒甚至可以在低溫下存活長達28天。
Coronaviruses are well known to be particularly resilient in terms of where they can survive. And researchers are now beginning to understand more about how this affects the spread of the new coronavirus.
眾所周知，冠狀病毒對環境具有高適應性，目前研究人員也在研究這個特性對新冠病毒傳播的影響。
Neeltje van Doremalen, a virologist at the US National Institutes of Health (NIH), and her colleagues at the Rocky Mountain Laboratories in Hamilton, Montana, have done some of the first tests of how long Sars-CoV-2 can last for on different surfaces. Their study, which has been published in the New England Journal of Medicine, shows that the virus could survive in droplets for up to three hours after being coughed out into the air. Fine droplets between 1-5 micrometres in size – about 30 times smaller than the width of a human hair – can remain airborne for several hours in still air.
美國國家衛生研究院（NIH）的病毒學家多雷瑪倫（Neeltje van Doremalen）和她在落基山實驗室(位於蒙大拿州漢密爾頓)的同事們對Sars-CoV-2在不同物體表面上能存活多久進行各種試驗。他們的研究已發表在《新英格蘭醫學雜誌》上，該研究顯示，新冠病毒在被咳出進入空中後，還能在飛沫中存活長達三個小時的時間。在靜止空氣中，直徑為1-5微米之間的飛沫（約比人髮小30倍）可以在空中停留數小時。
It means that the virus circulating in unfiltered air conditioning systems will only persist for a couple of hours at the most, especially as aerosol droplets tend to settle on surfaces faster in disturbed air.
也就是說在沒有加裝過濾設備的空調中流通的病毒最多只能存活幾個小時，而在不流通的空氣中，懸浮微粒更會快速地附著在物體表面上。
But the NIH study found that the Sars-CoV-2 virus survives for longer on cardboard – up to 24 hours – and up to 2-3 days on plastic and stainless-steel surfaces.
但NIH的研究發現，Sars-CoV-2病毒在紙板上存活的時間更長(長達24小時)；在塑膠和不銹鋼表面上存活的時間更可長達2-3天。
The findings suggest the virus might last this long on door handles, plastic-coated or laminated worktops and other hard surfaces. The researchers did find, however, that copper surfaces tended to kill the virus in about four hours.
這些結果表示，這種病毒可以在門把、塑膠塗層或層壓材料製的台面上，以及其他堅硬的表面上存活如此長的時間。不過研究人員確實也發現，病毒在銅材表面上往往只能存活大約四小時。
But there is a speedier option: research has shown that coronaviruses can be inactivated within a minute by disinfecting surfaces with 62-71% alcohol, or 0.5% hydrogen peroxide bleach or household bleach containing 0.1% sodium hypochlorite. Higher temperatures and humidity also tend to result in other coronaviruses dying quicker, although research has shown that a related coronavirus that causes Sars could be killed by temperatures above 56°C or 132°F (hotter than even a bath scalding enough to cause injury) at a rate of about 10,000 viral particles every 15 minutes.
但是，還有一個更快的選擇：研究顯示，用62-71％的酒精、0.5％的過氧化氫(雙氧水)漂白水或0.1％的次氯酸鈉漂白水消毒物體表面，就能在一分鐘內殺死冠狀病毒。高溫和高濕度也會使其他冠狀病毒死得更快，不過研究顯示，需要至少56°C或132°F以上的溫度（若用這個溫度的水洗澡可能會被燙傷）才能殺死造成SARS疫情的冠狀病毒，在這個條件下，大約每15分鐘能殺死1萬顆病毒顆粒。
The US Environmental Protection Agency (EPA) has now published a list of disinfectants and active ingredients that can be used against the Sars-CoV-2 virus. Ultraviolet light can also be used to disinfect some surfaces, but is not currently recommended for use on human skin.
目前美國國家環境保護署（EPA）公布了一張產品清單，載明了各種可以對抗Sars-CoV-2病毒的消毒劑和活性成分。紫外線也可以用來消毒某些物體表面，但是還不建議使用在人體皮膚上。
Although there is no data on how many virus particles will be in a single droplet coughed up by an infected person, research on the flu virus suggests smaller droplets can contain many tens of thousands of copies of the influenza virus. However, this can vary depending on the virus itself, where in the respiratory tract it is found and at what stage in the infection the person is.
儘管目前還沒有關於感染者咳出的每滴飛沫中會帶有多少病毒顆粒的相關數據，但是對流感病毒的研究卻顯示，較小的飛沫可帶有成千上萬的流感病毒顆粒。不過，這還要看病毒是在呼吸道的哪個部位以及感染者是處在哪個感染階段而定。
On clothing and other surfaces harder to disinfect, it is not yet clear how long the virus can survive. The absorbent natural fibres in cardboard, however, may cause the virus to dry up more quickly than on plastic and metal, suggests Vincent Munster, head of the virus ecology section at Rocky Mountain Laboratories and one of those who led the NIH study.
目前還不清楚在衣服等其他難以消毒的表層上，病毒可以存活多長的時間。落基山實驗室病毒生態學部負責人，同時也是上述NIH研究主要研究員之一的文森特·蒙斯特（Vincent Munster）表示，紙板中的親水性天然纖維可能是導致病毒死亡速度比在塑膠和金屬上更快的原因。
“We speculate due to the porous material, it desiccates rapidly and might be stuck to the fibres,” he says. Changes in temperature and humidity may also affect how long it can survive, and so may explain why it was less stable in suspended droplets in the air, as they are more exposed. “[We’re] currently running follow-up experiments to investigate the effect of temperature and humidity in more detail.”
他說：「我們推測，可能是因為多孔材料的緣故，讓病毒乾掉死亡的速度變快，還會讓病毒黏在纖維上。」溫度和濕度的變化也會影響其生存的時間，所以可以解釋為什麼在空氣中以懸浮微粒形式存在的病毒，穩定性會比較差，因為它們接觸到空氣中溫度濕度的機會比較大。「目前[我們]正在進行一些後續實驗，仔細研究溫度和濕度對病毒的影響力。」
The ability of the virus to linger for so long only underlines the importance of hand hygiene and cleaning of surfaces, according to Munster.
蒙斯特說：「病毒持久的存活能力只是在提醒我們保持手部衛生和清潔物體表面有多重要。」
“There is a potential for this virus to be transmitted via a variety of routes,” he says.
他說：「因為這種病毒還可能可以藉由更多途徑來進行傳播。」
* This article was edited on 18 March 2020 to add the fact that the research paper by Neeltje van Doremalen and colleagues has now been published in the New England Journal of Medicine. It has also been clarified that the virus's survival on natural fibres has only been tested on cardboard. The article was edited further on 24 March 2020 to add a link to the EPA's list of disinfectants and active ingredients that have claims for use against Sars-CoV-2.
*本文修改於2020年3月18日，補上目前多雷瑪倫及其同事的研究已在《新英格蘭醫學雜誌》上發表這件事。同時說明有關該病毒在天然纖維上的存活率，目前僅在紙板上進行過測試。2020年3月24日再度進行修改，補上EPA所列出能夠對抗Sars-CoV-2的消毒劑和活性成分清單的連結。
留言列表
科技 (2)
{{ article.title }}
