How pandemics spread

大型流行病是如何傳播的 - Mark Honigsbaum

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譯者: Ambrose Lam 審譯者: Regina Chu

（音樂）

(music)

（音樂）

We live in an interconnected, an increasingly globalized world.

我們住在一個彼此連緊，越來越一體化的世界

Thanks to international jet travel,

由於國際航班

people and the diseases they carry

它們所承載的人和疾病

can be in any city on the planet in a matter of hours.

可以在數小時內到達世上任何一個城市

And once a virus touches down,

當病毒着陸後

sometimes all it takes is one sneeze to spread

只不過一個噴嚏便可以把這個感染

the infection throughout the community.

傳播至整個社區

When humans were hunter-gatherers, roaming the wild savannas,

當人類還是獵人和採摘者，在曠野的大草原遊蕩

we were never in one place long enough,

我們不會在一個地方留得太久

and settlements were not large enough

聚居點也不會太大

to sustain the transmission of infectious microbes.

給有傳染性的細菌有機會傳開去

But with the advent of the agricultural revolution

但隨着農業革命於一萬年前來臨

10,000 years ago, and the arrival of permanent settlements

和在中東開始出現的固定居所

in the Middle East, people began living side-by-side with animals,

人們開始與動物毗鄰而居

facilitating the spread of bacteria and viruses

這便利了細菌和病毒

between cattle and humans.

在牲畜和人類之間傳播

Epidemics and pandemics come in many shapes and forms.

流行病和大型流行病有許多形態和形式

In 2010, for instance,

例如在2010年

a devastating earthquake struck Haiti,

海地遭遇破壞力極強的地震

forcing thousands of people into temporary refugee camps.

數以千計的人被迫要入住臨時難民營

Within weeks, the camps had become breeding grounds for cholera,

數星期內這些難民營成為霍亂菌的温床

a bacteria spread by contaminated water,

這病菌經由受污染的水傳播

triggering a country-wide epidemic.

從而引發全國性的流行病

But the most common cause of epidemics are viruses,

但流行病最普遍的成因是病毒

such as measles, influenza and HIV.

例如痲疹、流感和愛滋

And when they go global, we call them pandemics.

當流行病傳至世界各地，我們便稱之為大型流行病

Pandemics have occurred throughout human history,

大型流行病在人類歷史中多次出現

Some have left scars on the tissue and bone of their victims,

有些流行病會在受感染者的器官和骨上留下疤痕

while evidence for others comes from preserved DNA.

我們也可從受感染者身上找到病毒留下的DNA

For instance, scientists have recovered DNA

比如，科學家便從古埃及的木乃尹

from the bacteria that transmits tuberculosis

找到一種會傳染結核病

from the remains of ancient Egyptian mummies.

的細菌的DNA

And in 2011,

而在2011年

scientists investigating a plague pit in the city of London

調查倫敦市一次瘟疫的科學家

were able to reconstruct the genome of Yersinia pestis,

重組出鼠疫桿菌的基因組

the bacterium responsible for the Black Death of the 14th century.

而這細菌正是14世紀黑死病的原兇

It is thought the plague originated in China

科學家認為這次瘟疫源於中國

in around 1340,

約於1340年間

spreading west along the Silk Road,

它沿着絲路向西方傳播

the caravan route running from Mongolia to the Crimea.

即是由蒙古至克里米亞的商旅路線

In 1347, the plague reached the Mediterranean,

1347年，這瘟疫扺達地中海

and by 1400, it had killed in excess of

到了1400年，它已令超過三千四百萬

34 million Europeans, earning it the title,

歐洲人死亡，因而被稱為

the Great Mortality.

大瘟疫

It was later historians who called it the Black Death.

歷史學者後來才稱之為黑死病

However, by far the greatest pandemic killer

然而，導致最多人死亡的大流行病

is influenza.

是流行性感冒

Flu is constantly circulating between the Southern and Northern Hemispheres.

流感不停地在南北半球之間流傳

In North America and Europe,

在北美洲和歐洲

seasonal flus occur every autumn and winter.

季節性流感每年秋冬都會發生

As the majority of children and adults will have been exposed to the virus in previous seasons,

由於大部份兒童和成人都在過去的季節遇過這病毒

these illnesses are usually mild.

因此病情通常較温和

However, every 20 to 40 years or so

可是，每20或40年左右

the virus undergoes a dramatic mutation.

病毒會出現巨大的基因突變

Usually this occurs when a wild flu virus

這通常是因一個在鴨和家畜

circulating in ducks and farm poultry

流傳的温和病毒

meets a pig virus, and they exchange genes.

碰上了豬的病毒之後交換基因

This process is known as antigenic shift

這個過程稱為抗原移變

and has occurred throughout human history.

並在人類歷史上多次出現

The first recorded pandemic occurred in 1580.

有紀錄的第一個大型流行病發生於1580 年

The 18th and 19th centuries

十八和十九世紀

saw at least six further pandemics.

也發生過最少六次大型流行病

In terms of mortality,

死亡率方面

none can compare with the Great Flu Pandemic of 1918.

最嚴重的是1918年的大型流感

The first indication of the pandemic

這次大型流感的先兆出現於春天

came in the spring, when American troops in northern France

在法國北部的美國軍隊

began complaining of chills, headaches and fever.

開始感到發冷、頭痛和發燒

Then, the following September, at a U.S. Army barracks near Boston,

到了那年的九月，在波士頓附近一個美國軍營

soldiers started collapsing on parade,

士兵在步操時暈倒

prompting their removal to the camp infirmary.

他們隨後被送往軍營的醫院

As a surgeon there recalled,

一位醫生回憶說

two hours after admission, they had the mahogany spots over the cheekbones

士兵入院兩小時後，顴骨出現紅褐色的斑點

and a few hours later

在數小時後

you can begin to see the cyanosis extending from their ears

從他們的耳朵開始呈現發疳

and spreading all over the face.

並蔓延至整臉

It is only a matter of a few hours then until death comes,

到了這時，他們只剩下數小時生命

and it is simply a struggle for air until they suffocate.

期間他們會拼命喘氣直至他們窒息為止

On the S.S. Leviathan,

在利維坦號

a huge American transport en route to Bordeaux,

一艘由美國前往波爾多的輪船上

sick men hemorrhaged blood from their noses,

因為病了的人鼻孔溢血

turning the decks between their bunks slick with bodily fluids.

令他們床舖下的甲板佈滿了病人的體液

Meanwhile, British soldiers returning from northern France on furlough

與此同時，從法國北部休假回國的英軍

introduced the flu to Dover and other Channel ports,

將流感帶到多佛市和其他英倫海峽的港口

from where the virus was carried by rail to London.

病毒再從那些地方經火車傳到倫敦

By the time the pandemic had run its course

這大型流感的顛峰

in April 1919,

為1919年四月

an estimated 675,000 Americans

那時估計有六十七萬五千美國人

and 230,000 Britons were dead.

和二十三萬英國人病死了

In India alone, some 10 million were killed,

單在印度，病毒殺死了約一千萬人

and worldwide the death toll was an astonishing 50 million.

而全球的死亡數字更達到驚人的五千萬

But that was then.

這是那時的情況

Today, planes can transport viruses

今天，飛機只需較 1918 年短得多的時間

to any country on the globe

便可以把病毒

in a fraction of the time it took in 1918.

傳到世上任何一個國家

In February 2003, for instance,

例如，在 2003 年二月

a Chinese doctor arrived at the Metropole Hotel in Hong Kong

一名中國醫生入住香港的維景酒店時

feeling unwell.

感到身體不適

Unknown to him, he was harboring a new animal-origin virus called SARS,

他不知道自己身上藏着一種源於動物的新病毒 SARS

short for Severe Acute Respiratory Syndrome.

全寫是嚴重急性呼吸綜合症

Within 24 hours of checking into Room 913,

他入住酒店 913 號房的 24 小時內

sixteen other guests had been infected,

16 位其他客人受到感染

and over the following days five boarded planes to overseas destinations,

接着數天其中五人乘飛機前往外地

spreading the virus to Vietnam, Singapore and Canada.

因而把病毒傳到越南、星加坡和加拿大

Flights between Hong Kong, Toronto and other international cities were quickly grounded

香港、多倫多和其他國際城市之間的航班很快便停飛

and thanks to other emergency measures,

幸得其他緊急應變措施

a pandemic was averted.

一次大型流行病得以避免

By the time the outbreak was over four months later,

到了疾病爆發超過四個月後

SARS had infected 29 countries worldwide

SARS 已傳到了全球 29 個國家

and more than 1,000 people were dead.

超過千人因而死亡

For all that the virus was rapidly contained, however,

雖然病毒很快受到控制

there was little that could be done about the alarming news reports

我們卻無法阻止有線新聞渠道和網路

carried by cable news channels and the Internet.

散播這令人震驚的新聞

As bloggers added to the hysteria

由於博客散播了一些沒根據的消息

by spreading unfounded conspiracy theories,

加深了人的恐慌

tourism in Hong Kong and other affected cities ground to a halt,

香港和其他受影響城市的旅遊業完全停頓

costing businesses more than 10 billion U.S. dollars.

生意損失超過 100 億美元

One business, however, did very well.

然而，有一門行業卻其門如市

Above all, SARS was a reminder that pandemics have always been associated with panic.

最重要的是，SARS 提醒我們大型流行病總帶來恐慌

If history teaches us anything,

如果歷史給了我們甚麼教訓

it's that while pandemics may start small,

那就是大型流行病開始時可能規模細小

their impacts can be as dramatic as wars and natural disasters.

但它們的影響及得上戰爭和自然災禍

The difference today

今天有所不同的是

is that science gives us the ability to detect pandemics

科學可以讓我們從病發初期

right at the very beginning

便偵測到大型流行病

and to take action to mitigate their impacts

和採取行動，在它們廣為傳播前

before they spread too widely.

減低它們的影響

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