The Ebola Virus Explained — How Your Body Fights For Survival

What makes Ebola so dangerous? 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 to 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 cell's 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 trick specialized cells into ending their own lives 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 circumvent their defenses, it also manipulates some to signal to the cells that make up the blood vessels, telling them to 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, awakened by the virus, and the macrophages signals.

Then, they are not very effective against viruses and should not be involved in this fight and begin to do lots of stuff they shouldn't do. The neutrophils signal 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 starts killing loads of liver cells, causing organ failure and more internal bleeding.

And all those things are going on at the same time. As the virus spreads, it's like nukes exploding everywhere. One incident of this in one region will be problem enough. But now it's starting to happen everywhere at once. All the mechanisms of the immune system have evolved to handle infections work against you. And the virus continues to spread and spread.

Finally, it begins to infect more and more body cells while the body desperately struggles to stay alive. In a desperate last effort to turn the tide, the immune system launches a cytokine storm. A cytokine storm is an S.O.S signal that causes the immune system to launch all of its weapons all at once in a desperate kamikaze attack. This hurts the virus but leaves behind tons of collateral damage, especially in the blood vessels.

Paradoxically, the healthier the immune system, the more damage it can do to itself. More and more fluid leaves the bloodstream. Blood pours after every opening of the body. You become seriously dehydrated; there's just not enough 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 papers 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 fluids of a person who shows symptoms or from an infected bat. 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. That's 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. Revised by: Ace Ervite.