2020年经济学人 病毒传播

Which animal SARS-COV-2 leapt from to infect human beings remains¹ unknown.

目前还不清楚究竟是哪种动物将SARS-COV-2传染给了人类。

But the evidence suggests that bats were involved at some point—perhaps not as the immediate² source of the virus,

但有证据表明，蝙蝠在某种程度上参与了病毒的传播——也许不是作为病毒的直接来源，

but probably as the reservoir from which it ultimately came.

而是作为病毒的最终来源。

Almost certainly that was true of the virus which caused the original SARS outbreak, in 2002.

几乎可以肯定的是，导致2002年SARS爆发的病毒就是如此。

Though this was transmitted to people by palm civets, they probably caught it from horseshoe bats.

虽然这种病毒是通过椰子猫传染给人类的，但椰子猫可能是被菊头蝠感染的。

MERS, another coronavirus, is similarly suspected of starting in bats, though the immediate source of human infection is camels.

另一种冠状病毒，中东呼吸综合征冠状病毒也被怀疑是由蝙蝠引起的，尽管导致人类感染的直接来源是骆驼。

Bats are also reckoned to be behind the spread of Ebola and Marburg fevers,which are viral infections as well, though not caused by coronaviruses.

蝙蝠也被认为是埃博拉病毒和马尔堡热传播的幕后推手，尽管这两种就并不是由冠状病毒引起的，但它们也是病毒感染。

And vampire³ bats famously carry another virus, rabies.

吸血蝠还携带着另一种著名的病毒——狂犬病。

The idea that this may not be a coincidence has led people to ask if there is something special about bats

人们认为这可能不是巧合，这一想法这让人们不禁要问，蝙蝠是否有什么特别之处

which encourages the evolution within them of viruses predisposed to jump the species barrier and infect other sorts of animals. At the moment, the evidence is mixed.

促使病毒在它们体内进化，从而有可能跨越物种屏障，感染其他种类的动物。目前，证据比较混乱。

In favour of the idea is an experiment conducted recently by Cara Brook⁴ of the University of California, Berkeley, and published in February in eLIFE.

支撑这一想法的是近期由加州大学伯克利分校的Cara Brook进行并于2月发表于《eLIFE》的一项实验。

This suggests a possible mechanism⁵. Some bats have unusual immune systems,

这暗示了一种可能的机制。一些蝙蝠拥有不同寻常的免疫系统，

in which an antiviral process known as the interferon pathway is always active, rather than being switched on in response to infection.

在该系统中，被称为干扰素通路的抗病毒过程始终保持活跃，而不是仅在感染时被激活。

Dr Brook and her colleagues conducted experiments on cells from bats that have this arrangement and on others which do not

Brook博士和她的同事对拥有该种免疫系统以及没有这种系统的蝙蝠的细胞进行实验，

(and also on cells from monkeys, as a control). They concluded that always-on interferon pathways probably do speed up viral evolution.

（作为对照，也对猴子的细胞进行了实验）。他们总结称，永远活跃的干扰素通路可能确实加快了病毒进化。

That would make bats more abundant sources of virulent⁶ new viruses than other groups of mammals.

这会让蝙蝠成为比其他哺乳动物更丰富的新病毒来源。

Against the idea, however, is work published this week in the Proceedings⁷ of the National Academy of Sciences

然而，反对这种观点的是本周由格拉斯哥大学的Nardus Mollentze和Daniel Streicker

by Nardus Mollentze and Daniel Streicker of the University of Glasgow.

发表于《Proceedings of the National Academy of Sciences》的一项研究。

Dr Mollentze and Dr Streicker found that the number of viruses which have passed to people from 11 orders of mammals and birds

Mollentze和Streicker博士发现，11目哺乳动物和鸟类传给人类的病毒数量

is pretty much proportional to the number of species in each order. Bats are the second-most diverse mammalian order, after rodents⁸.

与每一目中物种的数量成比例。蝙蝠是仅次于啮齿动物的第二大哺乳动物目。

"It is therefore not surprising", Dr Mollentze observes, "that as a group they are associated with a large number of viruses."

Mollentze博士表示：“因此，作为一个群体，它们与大量的病毒有关，这并不奇怪。”

Although bat immune systems do indeed have the unusual features that interested Dr Brook and her colleagues,

虽然，蝙蝠的免疫系统确实有让Brook博士和她的同事感兴趣的特点，

Dr Mollentze and Dr Streicker found no evidence these caused bat-associated viruses to be more numerous

但Mollentze博士和Streicker博士并没有发现证据证明，这导致与蝙蝠相关的病毒

or more prone⁹ to infect people than viruses associated with other animal groups.

比与其他动物群体相关的病毒数量更多或更容易感染人类。

This study is in line with work done specifically on coronaviruses by Tracey Goldstein of University of California, Davis.

该研究与加州大学戴维斯分校的Tracey Goldstein针对冠状病毒的专门研究相一致。

In 2017 she and her colleagues published a piece of research in which they had tested for coronaviruses in bats,

2017年，她和她的同事发表了一项研究，她们在非洲、南非和亚洲的20个国家

rodents and primates¹⁰ (including people) in 20 countries in Africa, South America and Asia.

对蝙蝠、啮齿动物和灵长类动物（包括人类）的冠状病毒进行了测试。

Individual bat species normally had between one and five types of coronavirus.

单个蝙蝠种类通常携带冠状病毒类型的数量在1到5种之间。

(For comparison, human beings have seven, including the newly emerged SARS-COV-2.)

（作为比较，人类是7种，包括新出现的SARS-COV-2。）

Scale that up for the 1,400 different species of the animals and it means there are potentially more than 3,000 coronaviruses circulating in bats.

如果扩大到1400种不同种类的动物，那么这就意味着可能有超过3000种冠状病毒在蝙蝠体内流通。

This certainly increases the odds¹¹ that bats will be responsible for generating a coronavirus dangerous to people. But only because there are lots of them.

这无疑增加了蝙蝠产生对人类危险的冠状病毒的可能性。但这也只是因为它们数量众多。

1 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。

2 immediate   

adj.立即的；直接的，最接近的；紧靠的

参考例句：

• His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
• We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。

3 vampire   

n.吸血鬼

参考例句：

• It wasn't a wife waiting there for him but a blood sucking vampire!家里的不是个老婆，而是个吸人血的妖精！
• Children were afraid to go to sleep at night because of the many legends of vampire.由于听过许多有关吸血鬼的传说，孩子们晚上不敢去睡觉。

4 brook   

n.小河，溪；v.忍受，容让

参考例句：

• In our room we could hear the murmur of a distant brook.在我们房间能听到远处小溪汩汩的流水声。
• The brook trickled through the valley.小溪涓涓流过峡谷。

5 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

6 virulent   

adj.有毒的，有恶意的，充满敌意的

参考例句：

• She is very virulent about her former employer.她对她过去的老板恨之入骨。
• I stood up for her despite the virulent criticism.尽管她遭到恶毒的批评，我还是维护她。

7 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

8 rodents   

n.啮齿目动物( rodent的名词复数 )

参考例句：

• Rodents carry diseases and are generally regarded as pests. 啮齿目动物传播疾病，常被当作害虫对待。 来自《简明英汉词典》
• Some wild rodents in Africa also harbor the virus. 在非洲，有些野生啮齿动物也是储毒者。 来自辞典例句

9 prone   

adj.(to)易于…的，很可能…的；俯卧的

参考例句：

• Some people are prone to jump to hasty conclusions.有些人往往作出轻率的结论。
• He is prone to lose his temper when people disagree with him.人家一不同意他的意见,他就发脾气。

10 primates   

primate的复数

参考例句：

• Primates are alert, inquisitive animals. 灵长目动物是机灵、好奇的动物。
• Consciousness or cerebration has been said to have emerged in the evolution of higher primates. 据说意识或思考在较高级灵长类的进化中已出现。

11 odds   

n.让步，机率，可能性，比率；胜败优劣之别

参考例句：

• The odds are 5 to 1 that she will win.她获胜的机会是五比一。
• Do you know the odds of winning the lottery once?你知道赢得一次彩票的几率多大吗？