How can a virus overwhelm the very complex

defense system of the body so quickly

and so effectively?

Let's take a look at what Ebola does.

(Theme music)

Ebola is a virus.

A virus is a very small thing.

A bit of RNA or DNA

and a few proteins

and a hull.

It has no ability to do anything

by itself whatsoever,

and can only survive and proliferate by infecting cells.

To avoid this we have the immune system.

The immune system is super complex

so we develop a visual system

that makes it easy to understand.

So it looks like this:

Let's concentrate on the part that is critical to understanding Ebola

and ignore the rest.

So usually dendritic cells will activate the army

of anti-virus cells, support cells

and anti-body factories

that work together with the guard cells

wipe out the infection in a matter of days.

But when Ebola strikes, it directly

attacks the immune system.

Some of the first cells it takes over are

the dendritic cells, the brains of

the immune system.

The Ebola virus enters a dendritic cell by

binding into receptors for cell transport.

Once it is inside, it dissolves its outer hull and releases

its genetic material, nucleoproteins and enzymes.

In a nutshell it takes over the cell,

disables the cells protective mechanisms and

reprograms it.

The cell now becomes a virus production machine

and uses its resources to build Ebola viruses.

Once the cell is saturated, it dissolves the cell membrane

and millions of viruses are released into the tissue.

The virus not only prevents the dendritic cells

from activating the specialized and anti-virus forces,

it manipulates them into sending signal proteins

that tricks specialized cells

into ending their own life's prematurely.

So the immune system is seriously disrupted

and unable to react.

When the virus rapidly multiplies, we're talking billions,

there are cells that should deal with infected cells,

the natural killer cells, but they also get infected

and just die before they can prevent

the disease from spreading.

At the same time Ebola infects

the guard cells of the body

macrophages and monocytes,

not only managing to succumb them the defenses,

it also manipulates some to signal to

the cells make up the blood vessels

telling into release fluid into the body

Usually this makes sense, but in this case

it just causes mayhem.

All of the body's neutrophils are activated

awaken by the virus and the macrophages signals

then are not very effective against viruses and

should not be involve in this fight and

begin to do lots of stuffs they shouldn't do.

The neutrophils signals to the blood vessels to

release more fluid causing internal bleeding.

Another area of the body Ebola

attacks is the liver. The virus finds it

very easy to enter the liver and

it quickly stars killing lots of liver cells

and causing organ failure and more internal bleeding.

And all those things are going on at the same time.

As the virus spreads, it is like nukes exploiting every where.

One (unintelligibly) in one region will be problem enough

But now is starting to happen everywhere at once.

All the mechanisms of the immune system have evolve to

handle infections work against you.

And the virus continues to spread and spread.

And finally begins to infect more and more body cells

while the body desperately struggles to stay alive.

In a desperate last effort to turn untighted

the immune system launches a cytokine storm.

A cytokine storm is a S.O.S signal

that causes the immune system to launch all of its weapons,

all at once in a desperate kamikaze attack.

This helps the virus to leave behind tons of collateral damage,

specially in the blood vessels.

Paradoxically the healthier the immune system,

the more damage it can do to itself

More and more fluid leaves the blood stream.

Blood pours after every opening of the body.

You become seriously dehydrated

that just not now blood left to supply the organs with oxygen

and cells begin to die. If you reach this point

the chance of you dying is very high.

Currently six out of ten infected die from Ebola.

Wow! Ok. Ebola is nasty. So it’s time to panic, right?

No, not even close.

The severity of Ebola gets paper sold and

YouTube videos shared so everybody is talking about Ebola.

But currently the only way to get infected by Ebola

is to come into contact with the body fluid

whose person that shows the symptoms

Or from infected batch . So just don’t do that.

Ebola has killed 5,000 people since June 2014.

The common flu kills up to 500,000 people each year.

Malaria causes up to one million each year.

3,000 people every single day. Ten children since this video started.

So even if Ebola is terrible and scary,

don’t let yourself be scared. The most infectious thing about Ebola

is the media hype around it.

You could learn a bit more about the immune system though

Transcription made by Miriam Delgado

Subtitles by the Amara.org community