What happens to your body when you get the Ebola virus?

The world is experiencing the worst outbreak of the Ebola in recorded history. The outbreak in West Africa has already claimed more than 700 lives.

The virus can cause bleeding from the eyes and ears, but what actually kills you?

Ebola is transmitted through direct contact – it is not known to infect people through the air. It can be transmitted by an animal that carries the virus (such as a bat or primate, through contact with bodily fluids from a person who has the virus and is showing symptoms and through contact with items that are contaminated by the virus. For example, if a family member is caring for someone with Ebola, they will likely come into contact with vomit or diarrhea and could contract the illness. Ebola has been known to survive outside of a host for as long as a few days at room temperature.

Once inside the body, the virus gets in the body’s cells and replicates itself. Then the virus bursts out of the cells and produces a protein that wreaks havoc on the body. The protein, ebolavirus glycoprotein, attaches to cells on the inside of blood vessels, causing blood to leak from them. Ebola hampers the body’s ability to coagulate and thicken blood. Even people who show no outward symptoms of hemorrhaging, will experience leaking from blood vessels, which can, and usually do, lead to shock and death.

Ebola is deadly because it evades the body’s natural defenses. It blocks signals to white blood cells, which are in charge of raising the alarm to the immune system when it is under attack. Worse than that, the Ebola virus will actually infect immune cells and travel to other parts of the body including the liver, kidneys and brain. When a cell is infected and it bursts, the contents of the cell are spilled out into the body and activate molecules known as cytokines. The cytokines are present in such high numbers that they cause flu-like symptoms -- which are the first sign of Ebola.

Although Ebola is known for symptoms like bleeding out of the eyes and other mucus membranes, only about 20 percent of those with the virus experience those symptoms. Many people die before the virus reaches that point and may experience only minor bleeding, bleeding of the gums or bruising.

Flu-like symptoms occur in the first stages of the illness, followed by vomiting, diarrhea and low blood pressure. People who die from Ebola are usually killed from multi-organ failure and shock from bleeding from so many parts of the body.

Although the Ebola virus is very deadly, some people have survived it.

Survival is based largely on two factors – the person's general health and the type of exposure to the virus the person got. Recovery may be more likely if the person has a strong immune system in general, and if the exposure to the virus wasn't severe, in other words they were exposed to someone who was in the early stages of the illness.

Also, Ebola requires a known marker on the surface of human cells, which it uses to gain entry. Researchers have found that some people have cell likes without this marker, or with a mutated version of the marker, so Ebola cannot enter the cells.

However, Ebola research is still in the early phases, and knowledge about how the virus behaves and evolves is ongoing.