An outbreak of the deadly Marburg virus has been confirmed. Here's what you need to know

The World Health Organization this week confirmed an outbreak of the Marburg virus in Equatorial Guinea — the first time the tiny country in Central Africa has seen cases of the deadly illness.

Marburg, which is related to Ebola, is already being blamed for at least nine deaths in the country, and another 16 suspected cases are being investigated.

Without treatment, Marburg can be fatal in up to 88 per cent of people.

A 2004-05 outbreak in Angola killed 90 per cent of the 252 confirmed cases.

Here is what you need to know about this rare but dangerous virus. 

Marburg virus is believed to have originated in African fruit bats. It was first identified in 1967 in Germany and the former Yugoslavia, according to the U.S. Centers for Disease Control and Prevention, among people who had been working with green monkeys that had been imported from Uganda.

According to the World Health Organization (WHO), people can contract the virus through prolonged exposure in mines or caves where the bat colonies live.

The virus spreads between humans through direct contact with blood or other bodily fluids of an infected individual, or with surfaces contaminated with the virus, such as clothing or bed sheets.

Marburg is not airborne. 

Symptoms may begin "abruptly," according to WHO, and include high fever, severe headache and malaise. Muscle aches and pains are also common.

"It can impact every organ, and it essentially will cause a shock-like syndrome," said Dr. Isaac Bogoch, an infectious diseases specialist at Toronto General Hospital.

He said the virus can also cause gastrointestinal complications and a predilection to easy bleeding.

WHO says a rash can appear in the first seven days, and the central nervous system can be affected, resulting in confusion, aggression and irritability.

If death occurs, it generally happens eight to nine days after onset, following severe blood loss and shock.