戴口罩真的能讓你保持健康嗎？

Q. How effective are antimicrobial “courtesy masks” at preventing the spread of contagious airborne illnesses?

問：抗菌“禮貌口罩”在預(yù)防空氣傳播疾病方面效果如何?

A. The best evidence suggests that, when sick, wearing a mask can help to protect others from getting sick. And when well, wearing a mask around those who are sick will probably decrease your own chances of becoming infected. But the masks are far from foolproof.

答：最確鑿的證據(jù)表明，生病時(shí)戴口罩有助于避免其他人患病。健康者在患者周圍時(shí)戴口罩很可能會(huì)降低被感染的幾率。但口罩絕非萬無一失。

Courtesy masks, or what we doctors refer to as surgical masks, were introduced into the operating room in the late 1800s. They quickly became popular among a public eager to protect itself against the influenza pandemic of 1918.

禮貌口罩，也就是我們醫(yī)生所說的醫(yī)用口罩，是在19世紀(jì)晚期被引入手術(shù)室的。在1918年流感大流行期間，公眾渴望保護(hù)自己免于患上流感，所以這種口罩很快流行起來。

A century later, the advent of modern molecular techniques confirmed that surgical masks can indeed provide good protection against flu. In a 2013 study, researchers counted the number of virus particles in the air around patients with flu. They found that surgical masks decreased the exhalation of large viral droplets 25-fold. The masks were, however, less effective against the fine viral droplets that can remain suspended in the air longer and are therefore more infectious, cutting them by 2.8 times.

一個(gè)世紀(jì)后，現(xiàn)代分子技術(shù)證實(shí)了醫(yī)用口罩確實(shí)能夠很好地預(yù)防流感。在2013年的一項(xiàng)研究中，研究人員統(tǒng)計(jì)了流感患者周圍空氣中病毒顆粒的數(shù)量。他們發(fā)現(xiàn)，醫(yī)用口罩可將大病毒飛沫的吸入量減少至1/25。不過，這種口罩抵擋在空氣中懸浮時(shí)間更長(zhǎng)、因此更具傳染性的細(xì)小病毒飛沫的效果較差，只能將它們的吸入量減少2.8倍。

Surgical masks also afford fairly good protection for the worried well. In an oft-cited study of 446 nurses, researchers found surgical masks were as good, or nearly as good, at protecting the wearer against flu as respirators, a somewhat more high-tech, masklike device used in hospitals.

醫(yī)用口罩也能很好地保護(hù)擔(dān)心患病的健康人士。在一項(xiàng)經(jīng)常被引用的對(duì)446名護(hù)士的研究中，研究人員發(fā)現(xiàn)，醫(yī)用口罩在保護(hù)佩戴者免于感染流感方面幾乎和防護(hù)面罩一樣有效，后者是醫(yī)院使用的一種技術(shù)含量更高的面具式設(shè)備。

The work of Australian investigators provides further support for the value of the simple surgical mask. They estimate that in a home setting, wearing a surgical mask decreases a well person’s risk of getting sick by 60 percent to 80 percent.

澳大利亞調(diào)查人員的研究進(jìn)一步鞏固了簡(jiǎn)單的醫(yī)用口罩的價(jià)值。據(jù)他們估計(jì)，在居家環(huán)境中，佩戴醫(yī)用口罩能將一個(gè)健康人患病的風(fēng)險(xiǎn)降低60%至80%。

Unfortunately, most people fail to wear a mask faithfully enough to achieve this degree of protection, and the Centers for Disease Control and Prevention remains equivocal about the use of masks outside of health care settings. “No recommendation can be made at this time for mask use in the community by asymptomatic persons, including those at high risk for complications, to prevent exposure to influenza viruses,” the agency concludes on its website.

不幸的是，大多數(shù)人佩戴口罩不夠堅(jiān)持，不足以實(shí)現(xiàn)這種程度的保護(hù)，而美國(guó)疾病控制和預(yù)防中心(Centers for Disease Control and Prevention)對(duì)在醫(yī)療場(chǎng)合之外佩戴口罩的態(tài)度依然模棱兩可。該機(jī)構(gòu)在自己的網(wǎng)站上給出的結(jié)論是：“目前，對(duì)于無癥狀人群，包括并發(fā)癥高危人群，在社區(qū)中佩戴口罩預(yù)防流感病毒方面，我們并不能給出任何建議。”

If you don’t have a mask, or don’t want to wear one, standing at least six feet from an infected person will increase your chances for staying healthy. The air surrounding sick people, even if they aren’t coughing or sneezing, is loaded with small infectious aerosolized particles, and the farther you are from them, the better.

如果你沒有口罩，或者不想戴口罩，那么，站在離感染者至少6英尺的地方會(huì)增加你保持健康的幾率。即使患者沒在咳嗽或打噴嚏，他們周圍也充滿具有傳染性的霧狀微小顆粒，離它們?cè)竭h(yuǎn)越好。

Washing your hands frequently, of course, is also critical for staying healthy, since touching infected fingers to the eyes, nose or mouth can transmit infection.

當(dāng)然，經(jīng)常洗手對(duì)保持健康也很重要，因?yàn)槭艿轿廴镜氖种赣|摸眼睛、鼻子或口腔也會(huì)導(dǎo)致感染。