2020年经济学人 假面舞会（1）

Should people wear masks in public to slow the spread of SARS-COV-2?

人们应该在公共场合戴口罩来减缓SARS-COV-2的传播吗?

The World Health Organisation¹ (WHO) says don't bother. The British government agrees.

世界卫生组织（WHO）说不用这么麻烦。英国政府表示同意。

America's Centres for Disease Control and Prevention (CDC) initially² discouraged it but by the beginning of April had reversed course.

美国疾病控制与预防中心（CDC）起初不鼓励，但到4月初，情况发生了逆转。

In parts of Asia, including China, it is baked into public behaviour and encouraged by health agencies,

在包括中国在内的亚洲部分地区，即使没有持续的公共卫生危机，

even when there is no ongoing³ public health crisis. The issue?

戴口罩也被纳入公共行为并受到卫生机构的鼓励。问题呢？

Whether or not members of the public should wear face-masks in a bid to slow the spread of SARS-COV-2, the virus responsible for the covid-19 pandemic.

公众是否应该戴上口罩，以减缓SARS-COV-2的传播。SARS-COV-2是造成covid-19全球流感大流行的病毒。

Understanding all the ways that SARS-COV-2 is transmitted is a matter of active scientific discussion.

理解SARS-COV-2的所有传播途径是一个积极的科学讨论问题。

In the main, though, the virus hitches⁴ a ride on droplets⁵ of mucus or saliva⁶ that come out of the respiratory tracts⁷ of infected individuals.

不过，在大多数情况下，这种病毒只是附着在从感染者呼吸道流出的粘液或唾液飞沫上。

These may be expelled during normal breathing or, more commonly, as a cough that propels them a few metres into the air.

它们可能在正常呼吸时被排出体外，或者更常见的是，通过咳嗽将它们推向几米高的空中。

Thus propelled, they may reach another person's eyes, mouth or nose directly, and go on to infect cells in that individual's airways⁸.

因此，被弹出后，它们可能直接到达另一个人的眼睛、嘴巴或鼻子，然后继续感染那个人呼吸道的细胞。

Or they may land on a surface, on which the virus particles they contain could survive for hours, or even days,

或者它们会落在一个表面，表面上的病毒颗粒可以存活几个小时，甚至几天，

and from which those particles may eventually be transferred to others who touch the surface and then touch their own face or mouth.

并且这些颗粒最终可能会转移给那些触碰了这个表面，然后再触碰到自己的面部和嘴部的人体内。

There is no doubt that masks form a barrier to transmission, by stopping droplets passing from infected to uninfected people close by.

毫无疑问，口罩通过阻止飞沫从附近的感染者传播到未感染者，并通过这种方式形成了一个传播障碍。

The WHO recommends standard surgical⁹ masks as part of the personal protective equipment

WHO建议将标准医用口罩做为个人防护设备的一部分，

to be worn by doctors and nurses who are caring for covid-19 patients in clinics and hospitals. The same goes for anyone caring for a patient at home.

让在诊所和医院照顾covid-19病患的医生和护士佩戴。同理适用于任何在家照顾病人的人。

In most instances this is good enough, according to a meta-analysis of four randomised controlled trials

根据加拿大麦克马斯特大学的Mark Loeb本月在《流感》期刊上发表的

that was published this month in Influenza¹⁰ by Mark Loeb of McMaster University, in Canada.

对四项随机对照试验的荟萃分析结果来看，在多数情况下，这样做就足够了。

Indeed, Dr Loeb found no significant differences between surgical masks and their more sophisticated cousins, N95 respirators,

Loeb博士发现，在保护医护人员免受飞沫传播的病毒感染（包括包括由冠状病毒引起的感染）方面，

when it came to protecting healthcare workers from viral infections transmitted by droplets—including those caused by coronaviruses.

医用口罩和更加精制的N95口罩没有明显区别。

This suggests that N95 respirators (which are thicker, more rigid¹¹, and designed to form a close seal around the nose and mouth) should be reserved for riskier¹² situations.

这表明N95口罩（更厚、更硬，能在鼻子和嘴巴周围形成紧密的密封）应该预留给风险更大的情况。

"N95" means they block at least 95% of particles smaller than 0.3 microns across.

N95意味着它们至少能阻挡95%直径小于0.3微米的粒子。

They are, therefore, appropriate for situations when the threat comes from objects smaller than exhaled¹³ droplets— meaning less than about five microns across.

因此，它们适用于当威胁来自比呼出的飞沫还小的物体时，也就是直径小于5微米的物体时的情况。

These particularly include times when doctors and nurses need to "intubate" a patient in an intensive care unit,

这些情况包括当医生和护士需要在重症监护病房给病人“插管”的时候，

by inserting the tube of a ventilator deep into that patient's trachea. Intubation is a forceful procedure, and it creates aerosol¹⁴ particles

即将呼吸机的管子深深插入病人的气管中。插管是一种强制性的过程，在此过程中会产生气溶胶颗粒

(ie, smaller than five microns) that may carry viruses much farther through the air than droplets can manage.

（如小于5微米），这些颗粒携带病毒在空气中传播的距离可能远远超过飞沫所能达到的距离。

Though it remains¹⁵ unclear whether SARS-COV-2 is transmitted via aerosols¹⁶ in this way,

虽然目前还不清楚SARS-COV-2是否以这种方式通过气溶胶传播，

those performing intubations should be cautious, says Lisa Brosseau, a respiratory protection and infectious-diseases scientist at the University of Illinois at Chicago.

但那些给病人插管的医护应该谨慎，芝加哥伊利诺伊大学的呼吸道防护和传染病科学家Lisa Brosseau说到。

1 organisation   

n.组织，安排，团体，有机休

参考例句：

• The method of his organisation work is worth commending.他的组织工作的方法值得称道。
• His application for membership of the organisation was rejected.他想要加入该组织的申请遭到了拒绝。

2 initially   

adv.最初，开始

参考例句：

• The ban was initially opposed by the US.这一禁令首先遭到美国的反对。
• Feathers initially developed from insect scales.羽毛最初由昆虫的翅瓣演化而来。

3 ongoing   

adj.进行中的，前进的

参考例句：

• The problem is ongoing.这个问题尚未解决。
• The issues raised in the report relate directly to Age Concern's ongoing work in this area.报告中提出的问题与“关心老人”组织在这方面正在做的工作有直接的关系。

4 hitches   

暂时的困难或问题( hitch的名词复数 )； 意外障碍； 急拉； 绳套

参考例句：

• He hitches a lift with a long - distance truck. 他搭上了一辆长途卡车。
• One shoulder hitches upward in a shrug. 她肩膀绷紧，然后耸了耸。

5 droplets   

n.小滴( droplet的名词复数 )

参考例句：

• Droplets of sweat were welling up on his forehead. 他额头上冒出了滴滴汗珠。 来自辞典例句
• In constrast, exhaled smoke contains relatively large water droplets and appears white. 相反，从人嘴里呼出的烟则包含相当大的水滴，所以呈白色。 来自辞典例句

6 saliva   

n.唾液，口水

参考例句：

• He wiped a dribble of saliva from his chin.他擦掉了下巴上的几滴口水。
• Saliva dribbled from the baby's mouth.唾液从婴儿的嘴里流了出来。

7 tracts   

大片土地( tract的名词复数 )； 地带； （体内的）道； （尤指宣扬宗教、伦理或政治的）短文

参考例句：

• vast tracts of forest 大片大片的森林
• There are tracts of desert in Australia. 澳大利亚有大片沙漠。

8 AIRWAYS   

航空公司

参考例句：

• The giant jets that increasingly dominate the world's airways. 越来越称雄于世界航线的巨型喷气机。
• At one point the company bought from Nippon Airways a 727 jet. 有一次公司从日本航空公司买了一架727型喷气机。

9 surgical   

adj.外科的，外科医生的，手术上的

参考例句：

• He performs the surgical operations at the Red Cross Hospital.他在红十字会医院做外科手术。
• All surgical instruments must be sterilised before use.所有的外科手术器械在使用之前，必须消毒。

10 influenza   

n.流行性感冒，流感

参考例句：

• They took steps to prevent the spread of influenza.他们采取措施
• Influenza is an infectious disease.流感是一种传染病。

11 rigid   

adj.严格的，死板的；刚硬的，僵硬的

参考例句：

• She became as rigid as adamant.她变得如顽石般的固执。
• The examination was so rigid that nearly all aspirants were ruled out.考试很严，几乎所有的考生都被淘汰了。

12 riskier   

冒险的，危险的( risky的比较级 )

参考例句：

• Now they are starting to demand higher returns on riskier assets. 而今他们开始在风险更高的资产上要求更高的回报。
• The problem with that: RIM's business is getting riskier every quarter. 不过问题也随之而来：RIM面临的业务风险正逐季增大。

13 exhaled   

v.呼出，发散出( exhale的过去式和过去分词 )；吐出（肺中的空气、烟等），呼气

参考例句：

• He sat back and exhaled deeply. 他仰坐着深深地呼气。
• He stamped his feet and exhaled a long, white breath. 跺了跺脚，他吐了口长气，很长很白。 来自汉英文学 - 骆驼祥子

14 aerosol   

n.悬浮尘粒，气溶胶，烟雾剂，喷雾器

参考例句：

• They sprayed aerosol insect repellent into the faces of police.他们将喷雾驱虫剂喷在了警察的脸上。
• Aerosol particles affect visibility,climate,and our health and quality of life.气溶胶对大气能见度、气候变化以及人类健康等有重要影响。

15 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

16 aerosols   

n.气溶胶( aerosol的名词复数 )；喷雾剂；（气体中的）浮粒；喷雾器

参考例句：

• Aerosols are present throughout the atmosphere. 气溶胶存在于整个大气层。 来自辞典例句
• Deodorants are available as aerosols or roll-ons. 除臭剂有喷雾装或滚抹装。 来自辞典例句