in drawings and carvings of menacing dogs.

描繪或雕刻，表現出他們對凶狠狗類的恐懼。

But rabies is scary for more reasons than just a painful bite.

但比起疼痛的咬傷，狂犬病還有更恐怖的地方。

Because once the virus is inside us, it not only destroys our body, but damages our mind,

因為一旦病毒進入體內，不只會破壞身體，還會對我們的心理造成傷害，

and it can happen fast, or lay dormant for years before fatally attacking.

它可以發生得很快，或是在造成致命傷害前潛伏多年。

So how exactly do we get from a dog bite to a complete behavioral change to...death?

那麼，我們是如何從狗的咬傷，完全轉變成......死亡？

The virus that causes rabies is spread through saliva, so the most common way to contract

導致狂犬病的病毒完全經由唾液傳播，所以最常見感染狂犬病的方式是

rabies is through an animal bite, most likely from a dog, bat, raccoon, skunk or fox.

透過動物的咬傷，最主要是來自狗、蝙蝠、浣熊、臭鼬、或狐狸

There have been a few, rare cases of transmission through infected organ donors and an even

有些罕見的傳染病例是透過，器官捐贈者受感染的器官，甚至更罕見的是

rarer instance of a lab accident, but for the most part it comes down to a bite from a rabid animal.

實驗室事故，但大多情況都是狂犬病動物的咬傷。

So even though it's a virus that can infect and kill humans, it's studied considerably in veterinary labs.

因此，即使它是可以感染和殺死人的病毒，也在獸醫實驗室中得到很大的研究。

OK.

好了。

I am Dr. Susan Moore.

我是蘇珊．摩爾醫生。

I'm the laboratory director of the rabies laboratory at Kansas State University, part

我是堪薩斯州立大學狂犬病實驗室的實驗室主任，

of the veterinary diagnostic lab within the vet school here.

這是校內獸醫診斷實驗室的一部分。

We are the largest rabies serology laboratory in the world.

我們是世界最大的狂犬病血清學實驗室。

So the rabies virus is in the family lyssavirus,

狂犬病是麗沙病毒屬

lyssa means rage really.

狂犬病指的真的是狂怒。

So that kind of tells you what this group of viruses are capable of.

算是告訴你這組病毒的能力。

And what they're capable of is causing a very quick and painful death caused by the

它們的能力就是使病毒進入你的大腦

virus making its way into your brain.

造成相當快速且痛苦的死亡。

It's a neurotropic virus.

它是親神經性病毒。

So that means it's preferentially going to infect neural tissue or neural cells.

這代表它會優先感染神經組織或神經細胞。

So when it gets injected into the skin or the muscle, it's not going to replicate all

在它注入皮膚或肌肉時，無法複製得這麼順利

that well but all it needs to do is replicate enough that it can get to that neuromuscular

但它只需要複製一定的量，來到達神經肌肉接合處

junction where that it can go from the muscle cells into the central nervous system.

在那裡，可以從肌肉細胞進入中樞神經系統。

Now, at this point you'd think your immune system would kick in, recognize this dangerous intruder and destroy it.

此時，你會認為免疫系統開始起作用，將它視為危險的入侵者並摧毀它。

But, your immune system doesn't see it.

但你的免疫系統看不見它。

This is thought to be because the virus replicates slowly in the muscle tissue, slow enough not to cause any alarm.

原因是病毒在肌肉組織中複製得非常慢，慢到不會引起任何警報。

This gives it a chance to reach the nervous system, where it hitches a ride up to the

這使病毒有機會到達神經系統，在那搭便車往上爬到大腦

brain and slips through the blood brain barrier.

並滑過血腦障壁。

It's behind this shield where the rabies virus can flourish while still being able

在這個盾牌後，狂犬病病毒可以活躍起來，

to hide from our immune system, because the blood brain barrier evolved to keep dangerous or harmful things out.

並藏在免疫系統裡，因為血腦障壁的變體會防止危險或有害的東西進入。

But sometimes that includes immune cells.

但有時也包括免疫細胞。

In fact, if T cells do get past the blood brain barrier, the rabies virus has evasion

事實上，如果 T 細胞確實通過血腦障壁，狂犬病病毒就有躲避的方式，

techniques where it actually kills the T cells that are coming in.

其實就會殺死進入的 T 細胞。

As the virus replicates in the brain, it starts to mess with the brain's cellular proteins, causing neural dysfunction.

隨著病毒在大腦複製，它會開始擾亂腦中的細胞蛋白，導致神經功能障礙。

This is where certain symptoms of rabies start and how you can tell the infection has fully set in.

這是狂犬病的某些症狀開始，及完全確定感染的時候。

Once the infection has fully set in, it will start traveling back out through the nerves into innervated organs, hair follicles.

一旦感染完全發生，它會開始透過神經，來回進入受神經支配的器官、毛囊。

But again, particularly through to the salivary glands.

但一樣，特別是通過唾腺。

So that it could be transmitted out.

這樣就可以傳播出來。

These neurological symptoms also help the virus transfer to a new host.

這些神經系統症狀也有助於病毒轉移到新宿主。

Hypersalivation ensures there is enough rabies-infected saliva in the optimal transmission location, your mouth.

唾液分泌過多會讓受狂犬病感染的唾液有足夠的量，位於最佳傳播位置：嘴巴。

And hydrophobia, or trouble swallowing, ensures that it stays there.

而恐水症或是吞嚥困難，要確保它待在那裡。

In animals, the aggression can result in an attack on another animal or a human.

在動物中，這種侵占會導致攻擊別的動物或人類。

Put all three of those together and you have a very effective way to ensure the rabies virus is passed on.

將這三個放在一起，會有個相當有效的方法，來確保狂犬病病毒的傳播。

Saliva is the way that rabies is transmitted.

唾液是狂犬病的傳播方式。

The way the virus is adapted, it is not in blood.

病毒適應這種方式，而不是利用血液。

It's not in body fluids.

它不在體液中。

So it has to find a way to be transmitted effectively, right, to perpetuate its existence.

因此，它必須找到一種有效的傳播方式，讓它永久存在。

Now, this neurological damage caused by the infection is the thing that finally tips off the immune system.

這種由感染引起的神經損傷，最後會告訴免疫系統。

However, at this point it's too late.

然而，這個時間點已經太遲了。

Even though your immune system is finally going after the virus, it has already spread throughout the body.

即使你的免疫系統最後會去對付病毒，但它已遍布全身。

After that you have to remember this period is pretty short.

之後你必須記住這段時間很短。

There's just a couple days because then it'll progress into a coma and then death which

只有幾天而已，因為之後會進入昏迷狀態，然後死亡，

is usually due to some kind of organ failure.

通常是由於某個器官衰竭。

But a bite from a rabid animal doesn't always mean certain death.

但狂犬病動物的咬傷不一定會造成死亡。

People who have been exposed to the rabies virus can get a series of shots that can boost

暴露於狂犬病病毒的人，可以利用一系列的注射來提升免疫系統

the immune system and fight off the virus, you just need to get to it before it reaches the brain.

並抵禦病毒的攻擊，只需要在病毒到達大腦前注射。

So surviving rabies is all about timing and the location where you get bit.

因此，免於狂犬病的關鍵是時間和你被咬的位置。

Where you get bit.

你哪邊被咬。

It plays a big role.

非常重要。

So since the virus has to travel through the nerve system, the closer, and get to the brain,

由於病毒必須透過神經系統傳播，所以越接近大腦，

the closer that bite is to the brain, the better for the virus.

被咬的位置越接近大腦，就對病毒越有利。

Bats are a danger for that reason that it's going to be biting probably around

蝙蝠很危險，因為它可能會咬

your head or your hands. But also you don't notice a bat bite because the teeth are so small

你的頭或手。 但你也不會注意到蝙蝠的咬傷，因為牙齒很小，

and they are so small.

傷口也很小。

Maybe.

也許說

You have a bat on your shoulder and you don't know it.

你的肩膀被蝙蝠咬到，但你都不知道。

You just looked on your shoulder, didn't you?

你剛看了一下你的肩膀，沒錯吧？