So I'd like to start by focusing on

一種世界上最危險的動物。

the world's most dangerous animal.

此時此刻，當人們說起什麽是危險的動物，

Now, when you talk about dangerous animals,

大多數人也許會想到獅子或者老虎或者鯊魚。

most people might think of lions or tigers or sharks.

但是，毋庸置疑，那種最危險的動物

But of course the most dangerous animal

是蚊子。

is the mosquito.

在漫長的人類歷史長河裡，

The mosquito has killed more humans

蚊子比其他動物殺掉了更多的人類。

than any other creature in human history.

實際上，也許把所有被其他動物殺死的人數加起來的總和，

In fact, probably adding them all together,

也不會多於僅是被蚊子幹掉的人類性命的數量。

the mosquito has killed more humans.

並且被蚊子殺死的人類多於在戰爭和

And the mosquito has killed more humans than wars

瘟疫里死亡的人類。

and plague.

也許你會情不自禁地想，

And you would think, would you not,

以我們所擁有的科技，以我們所有的社會進步，

that with all our science, with all our advances in society,

更好的生活城鎮， 更好的文明， 更好的衛生條件，

with better towns, better civilizations, better sanitation,

更多的財富，我們應該可以更好地控制蚊子的數量，

wealth, that we would get better at controlling mosquitos,

並因此減少蚊子所帶來的疾病。

and hence reduce this disease.

但是事實並非全如此。

And that's not really the case.

如果我們可以控制蚊子的數量，這個世界上就不會

If it was the case, we wouldn't have

每年都有2到3億的人口被瘧疾所侵害，

between 200 and 300 million cases of malaria every year,

我們也不會有

and we wouldn't have

150萬人口每年死於瘧疾，

a million and a half deaths from malaria,

我們更不會有一種疾病，

and we wouldn't have a disease

在大約50年前還不為人所知，

that was relatively unknown 50 years ago

但是在一夜之間，成為

now suddenly turned into

由蚊子傳播的病毒裡，最為危險的一種，

the largest mosquito-borne virus threat that we have,

這種疾病的名字叫做登革熱。

and that's called dengue fever.

在50年前，幾乎沒有一個人聽說過這個名字，

So 50 years ago, pretty much no one had heard of it,

確切地說，沒有一個生活在歐洲的人聽說過這個名字。

no one certainly in the European environment.

但是，根據世界衛生組織的報告，迄今為止，

But dengue fever now, according to the World Health Organization,

每年有5千萬至一億的人感染登革熱，

infects between 50 and 100 million people every year,

這個數量相當於整個

so that's equivalent to the whole of the population

英國的人口每年都被感染登革熱。

of the U.K. being infected every year.

其他的估計顯示，大概每年被感染的人數

Other estimates put that number at roughly double

是世界衛生組織所報告人數的兩倍。

that number of infections.

並且，登革熱傳播的速度是異常的快。

And dengue fever has grown in speed quite phenomenally.

在過去50年間，登革熱的發生率

In the last 50 years, the incidence of dengue

已經翻了三十倍。

has grown thirtyfold.

現在，讓我給你們一點點關於登革熱的知識，

Now let me tell you a little bit about what dengue fever is,

特別是要給那些還不知道它是什麽的人們。

for those who don't know.

現在假設你要去度假，

Now let's assume you go on holiday.

假設你要去加勒比海度假，

Let's assume you go to the Caribbean,

或這假設你去墨西哥。或者，你去拉丁美洲，

or you might go to Mexico. You might go to Latin America,

亞洲，非洲，或者沙烏地阿拉伯任何一個地方。

Asia, Africa, anywhere in Saudi Arabia.

或者是去印度，遠東地區。

You might go to India, the Far East.

不管是你去哪裡，其實都無所謂。因為在任何一個地方，都是同一種蚊子，

It doesn't really matter. It's the same mosquito,

和同一種由那種蚊子傳播的疾病。 你都有危險會被感染到。

and it's the same disease. You're at risk.

現在假設你被一隻蚊子叮了，

And let's assume you're bitten by a mosquito

並且這個蚊子攜帶那種病毒。

that's carrying that virus.

嗯，這時，你會產生類似感冒的症狀。

Well, you could develop flu-like symptoms.

這些症狀可能會顯得很輕微。

They could be quite mild.

你也許會產生噁心，頭痛的症狀，

You could develop nausea, headache,

你會感覺你的肌肉在收縮，

your muscles could feel like they're contracting,

並且你可能會感覺你的骨頭在四分五裂。

and you could actually feel like your bones are breaking.

這種感覺其實是這種病昵稱的來源---

And that's the nickname given to this disease.

裂骨燒，

It's called breakbone fever,

因為你的身體就會有這種感覺。

because that's how you can feel.

奇怪的是，當你被

Now the odd thing is, is that once you've been bitten

這種蚊子叮咬了以後，並且你已經感染這種疾病，

by this mosquito, and you've had this disease,

你的身體會產生抗體，

your body develops antibodies,

也就是說，如果你再次被 帶有同一種病毒的蚊子叮咬以後，

so if you're bitten again with that strain,

你不會被感染。

it doesn't affect you.

但是這不僅僅只有一種病毒，而是四種。

But it's not one virus, it's four,

那種幫助你對其中某一種病毒產生抗體的保護措施，

and the same protection that gives you the antibodies

那種保護你不再被之前感染你的病毒所感染的保護措施，

and protects you from the same virus that you had before

實際上會讓你更容易被其他的三種病毒所感染。

actually makes you much more susceptible to the other three.

也就是說，下次如果再次感染登革熱，

So the next time you get dengue fever,

而且是另外一種病毒系，你就會更容易被它侵犯，

if it's a different strain, you're more susceptible,

你很可能會有更加嚴重的症狀，

you're likely to get worse symptoms,

而且，你更可能會有那些比較嚴重的症狀，

and you're more likely to get the more severe forms,

像是出血熱，或者休克綜合症。

hemorrhagic fever or shock syndrome.

所以，你最好是一次都不要感染登革熱，

So you don't want dengue once,

並且絕對不要被感染第二次。

and you certainly don't want it again.

那爲什麽登革熱傳播的速度如此之快呢？

So why is it spreading so fast?

原因就是整個東西---

And the answer is this thing.

---埃及伊蚊。

This is Aedes aegypti.

這種蚊子來自於北非，正如牠的名字所顯示，

Now this is a mosquito that came, like its name suggests,

並且牠們散布到世界各個角落。

out of North Africa, and it's spread round the world.

實際上，某一隻蚊子，在牠整個生命過程中，

Now, in fact, a single mosquito will only travel

只能飛行大約200碼（182.93米）的距離。 牠們並不能飛行太遠。

about 200 yards in its entire life. They don't travel very far.

但是牠們真正在行的是 “搭便車”，

What they're very good at doing is hitchhiking,

特別是牠們的卵。

particularly the eggs.

牠們會把卵產在清澈的水裡，任何的水池里，水坑里，

They will lay their eggs in clear water, any pool, any puddle,

任何小鳥戲水的池子里，花盆里，

any birdbath, any flower pot,

只要是任何有清水的地方，牠們就會產卵，

anywhere there's clear water, they'll lay their eggs,

並且，如果那種清水是靠近碼頭，或是港口的地方，

and if that clear water is near freight, it's near a port,

只要是任何靠近交通運輸的地方，

if it's anywhere near transport,

這些卵就會被傳播到世界各地。

those eggs will then get transported around the world.

這就是事實的真相。是人類

And that's what's happened. Mankind has transported

把這些卵傳播到了世界的各個角落。

these eggs all the way around the world,

這些害蟲已經大量傳播到了超過100個國家，

and these insects have infested over 100 countries,

這些國家一共有25億人口生活其中。

and there's now 2.5 billion people living in countries

也就是說這25億人口與這些蚊子一起生活。

where this mosquito resides.

給你舉一些簡單的例子

To give you just a couple of examples

來說明牠們傳播的速度有多麼驚人，

how fast this has happened,

在1970年代中期，巴西申報說，“我國沒有埃及伊蚊。”

in the mid-'70s, Brazil declared, "We have no Aedes aegypti,"

但是現在，他們已經每年花費近十億美金，

and currently they spend about a billion dollars now

試圖去除或者控制這些蚊子，

a year trying to get rid of it, trying to control it,

並且只是眾多蚊子中的一種。

just one species of mosquito.

我記不清楚是在兩天前還是昨天，

Two days ago, or yesterday, I can't remember which,

我看到路透社的一篇報導說，

I saw a Reuters report that said

馬德拉群島發現了他們島上第一批登革熱的爆發，

Madeira had had their first cases of dengue,

有52人被確認感染了登革熱， 其他400個人“可能被感染”。

about 52 cases, with about 400 probable cases.

那是兩天前。

That's two days ago.

有趣的是，馬德拉群島在2005年， 第一次發現有這種害蟲的存在，

Interestingly, Madeira first got the insect in 2005,

到現在，也就是幾年以後，

and here we are, a few years later,

第一批登革熱就在那裡爆發了。

first cases of dengue.

所以，可以確定的是，只要那種蚊子傳播到的地方，

So the one thing you'll find is that where the mosquito goes,

就會有登革熱。

dengue will follow.

只要那種蚊子到了某一個地區，

Once you've got the mosquito in your area,

只要任何人到了那個被登革熱感染的地區，

anyone coming into that area with dengue,

蚊子就會叮咬那些人，然後去其他地方繼續叮咬，

mosquito will bite them, mosquito will bite somewhere else,

去其他地方繼續咬，繼續咬，

somewhere else, somewhere else,

然後這就形成了大範圍傳播的流行病。

and you'll get an epidemic.

所以我們人類必須要真真正正地懂得如何殺死蚊子。

So we must be good at killing mosquitos.

我的意思是，那其實並不是很難。

I mean, that can't be very difficult.

也就是說，有兩種主要的方法。

Well, there's two principle ways.

第一種方法是你要使用殺幼蟲劑。

The first way is that you use larvicides.

你使用化學製劑。將化學製劑放入牠們產卵繁殖的水中。

You use chemicals. You put them into water where they breed.

但是在現代都市生活的環境里，使用這種方法是極其困難的。

Now in an urban environment, that's extraordinarily difficult.

你必須要把這些化學藥物投放到每一個水池，

You've got to get your chemical into every puddle,

每一個水盆，每一個樹幹裡。

every birdbath, every tree trunk.

這其實是不現實的。

It's just not practical.

第二種你可以使用的方法

The second way you can do it

是當這些害蟲在飛行的時候把牠們殺死。

is actually trying to kill the insects as they fly around.

這是一張“噴霧殺蟲”的照片。

This is a picture of fogging.

人們所做的，其實是把

Here what someone is doing

化學殺蟲劑跟煙霧混合在一起，

is mixing up chemical in a smoke

然後把那種混合物撒到環境中去。

and basically spreading that through the environment.

其實跟你是用空氣噴霧器是一回事。

You could do the same with a space spray.

這些噴霧是讓人感到不舒服的東西，

This is really unpleasant stuff,

而且，如果它是有效的的話，世界上就不會有

and if it was any good, we wouldn't have this massive increase

大量增多的蚊子，以及大量增多的登革熱的病例。

in mosquitos and we wouldn't have this massive increase in dengue fever.

也就是說，這種噴霧的方法並不有效。但是，它也許是

So it's not very effective, but it's probably

我們目前最好的方法了。

the best thing we've got at the moment.

不過，實際上，你和我最好的防蚊措施

Having said that, actually, your best form of protection

就是穿長袖衣服

and my best form of protection is a long-sleeve shirt

以及一點點防蚊水（diethyltoluamide、待乙妥）。

and a little bit of DEET to go with it.

所以，讓我們重新開始。讓我們一起設計一種產品，

So let's start again. Let's design a product,

馬上就開始，一起決定我們到底想要什麽產品。

right from the word go, and decide what we want.

嗯，我們當然是需要一種

Well we clearly need something that is effective

能有效減少蚊子數量的東西。

at reducing the mosquito population.

只隨機地殺蚊子是沒有意義的。

There's no point in just killing the odd mosquito here and there.

我們希望的是找到能夠大量減少蚊子族群的方法，

We want something that gets that population right the way down

這樣蚊子就不能傳播疾病了。

so it can't get the disease transmission.

我們清楚的知道，這種產品必須對人類是無害的。

Clearly the product you've got has got to be safe to humans.

因為我們要在人類生活的範圍里使用它。

We are going to use it in and around humans.

它必須得非常安全。

It has to be safe.

我們也不希望這種東西對環境產生長久持續的影響。

We don't want to have a lasting impact on the environment.

我們不想要(對環境)有不可逆的影響。

We don't want to do anything that you can't undo.

也許會有一種更好的產品會在20或者30年後出現。

Maybe a better product comes along in 20, 30 years.

沒關係。我們不想讓環境受到長久的影響。

Fine. We don't want a lasting environmental impact.

我們想要的是相對便宜的，或有成本效益的，

We want something that's relatively cheap, or cost-effective,

因為有太多，太多的國家被牽扯其中，

because there's an awful lot of countries involved,

而且，其中一些國家是新興的市場，

and some of them are emerging markets,

在這些新興市場裡，有一些是低收入的國家。

some of them emerging countries, low-income.

最後，我們想要的是針對某一種蚊子的產品。

And finally, you want something that's species-specific.

我們想除掉那種傳播登革熱的蚊子，

You want to get rid of this mosquito that spreads dengue,

但是你不想殺掉其他所有的昆蟲。

but you don't really want to get all the other insects.

有些昆蟲是有益的。有些在生態系中扮演很重要的角色。

Some are quite beneficial. Some are important to your ecosystem.

但這種蚊子不是有益的。牠們侵犯我們。

This one's not. It's invaded you.

但是你不想幹掉所有的昆蟲。

But you don't want to get all of the insects.

你只想幹掉這一種而已。

You just want to get this one.

而且在大多數情況下，你會發現這種昆蟲

And most of the time, you'll find this insect

就生活在你的家裡，

lives in and around your home,

所以，無論我們做什麼，必須能消滅這種昆蟲。

so this -- whatever we do has got to get to that insect.

我們必須要在人們的房子里，臥室裡，

It's got to get into people's houses, into the bedrooms,

廚房裡使用。

into the kitchens.

蚊子有兩個生物特性

Now there are two features of mosquito biology

著實可以幫助我們做好這個科學研究專案（殺蚊子的專案），

that really help us in this project,

第一個特性是公蚊子不咬人。

and that is, firstly, males don't bite.

叮咬你的，全都是母蚊子。

It's only the female mosquito that will actually bite you.

公蚊子不能夠咬你，也不會想要咬你。

The male can't bite you, won't bite you,

牠們沒有那種能夠叮咬你的口器。

doesn't have the mouth parts to bite you.

所以，咬你的只是母蚊子。

It's just the female.

第二個特性是一個現象，

And the second is a phenomenon

即，公蚊子非常擅長於找到母蚊子。

that males are very, very good at finding females.

如果你釋放了一隻公蚊子，

If there's a male mosquito that you release,

而且碰巧有一隻母蚊子在附近， 那隻公蚊子一定會找到那隻母蚊子。

and if there's a female around, that male will find the female.

基本上，我們已經利用了這兩種特性。

So basically, we've used those two factors.

所以，通常狀況下，

So here's a typical situation,

公蚊子遇到母蚊子，然後就繁殖大量的後代。

male meets female, lots of offspring.

僅一隻母蚊子一次會產下

A single female will lay about

多達100個卵。

up to 100 eggs at a time,

在牠一生裡，會產下多達500個卵。

up to about 500 in her lifetime.

如果那一隻公蚊子攜帶了

Now if that male is carrying a gene

會導致後代死亡的基因，

which causes the death of the offspring,

那麼這些後代就不會存活，

then the offspring don't survive,

也就是說，交配的結果是什麽都沒有，

and instead of having 500 mosquitos running around,

而不是500隻活蹦亂跳的蚊子。

you have none.

說得誇張一點，我稱他們為沒有生育力的蚊子，

And if you can put more, I'll call them sterile,

因為這些後代會在不同的生命階段里死亡，

that the offspring will actually die at different stages,

但是我們稱這些公蚊子為“不育蚊”。

but I'll call them sterile for now.

如果你將更多的“不育蚊”放到自然環境裡，

If you put more sterile males out into the environment,

那麼，母蚊子就更有可能會找到“不育蚊”，

then the females are more likely to find a sterile male

而不是有生育能力的公蚊子， 這樣的話，你就可以減少這種蚊子的數量。

than a fertile one, and you will bring that population down.

所以，當這些“不育”公蚊子出去尋找母蚊子的時候，

So the males will go out, they'll look for females,

牠們會交配。如果交配成功，（因為基因缺陷）就沒有後代存活。

they'll mate. If they mate successfully, then no offspring.

如果牠們沒有找到母蚊子，那麼，牠們最終都會死。

If they don't find a female, then they'll die anyway.

牠們本身只能存活幾天。

They only live a few days.

這就是我們現在正在做的。

And that's exactly where we are.

所以，這就是

So this is technology that was developed

幾年前在牛津大學研發出來的技術。

in Oxford University a few years ago.

這個公司叫做“Oxitec”，我們已經

The company itself, Oxitec, we've been working

工作了10年，用的研發方法

for the last 10 years, very much on a sort of similar

與製藥公司研發藥物的方法類似。

development pathway that you'd get with a pharmaceutical company.

也就是說，己經花了約十年的時間，去做內部評估，測試，

So about 10 years of internal evaluation, testing,

才能夠到達我們認為“一切準備就緒”的階段。

to get this to a state where we think it's actually ready.

接下來，我們己經到野外去測試，

And then we've gone out into the big outdoors,

必須得到當地社區的同意，

always with local community consent,

並且先得到必要的許可。

always with the necessary permits.

我們已經在開曼群島做了實地測驗，

So we've done field trials now in the Cayman Islands,

另外，在馬來西亞做了一個小的實地測驗，

a small one in Malaysia,

並在巴西做另外兩個實地測驗。

and two more now in Brazil.

那麼，結果如何？

And what's the result?

嗯，結果都非常的好。

Well, the result has been very good.

在投放“不育蚊”的四個月以後，

In about four months of release,

我們已經把蚊子的數量--

we've brought that population of mosquitos

--大多數情況下，我們的實驗地是那些

— in most cases we're dealing with villages here

只有2000、3000人的村子，

of about 2,000, 3,000 people, that sort of size,

一切都“從小”開始---

starting small —

在四個月的時間裡，我們已經成功地

we've taken that mosquito population down

將蚊子族群的數量減少了85%。

by about 85 percent in about four months.

實際上，要想繼續再算剩下的蚊子的數量

And in fact, the numbers after that get,

是非常，非常困難的，因為根本就沒有什麽蚊子剩下了。

those get very difficult to count, because there just aren't any left.

那正是我們在開曼群島看到的結果，

So that's been what we've seen in Cayman,

也正是我們在巴西的

it's been what we've seen in Brazil

實地測試裡看到的結果。

in those trials.

現在我們正在做的是

And now what we're doing is we're going through a process

這個實驗放到有50,000人口的城鎮裡，

to scale up to a town of about 50,000,

這樣的話，我們就可以看到 這個實驗在大範圍的地區效果如何。

so we can see this work at big scale.

另外，在牛津，我們已經有一個生產小組，

And we've got a production unit in Oxford,

確切地說，是在牛津的南部， 這個生產小組負責製造“不育蚊”。

or just south of Oxford, where we actually produce these mosquitos.

我們可以在比這塊紅地毯大一點的空間裡

We can produce them,

製造這些蚊子