Equatorial Guinea has confirmed its first-ever outbreak of Marburg virus disease, following the deaths of at least nine people in Kie-Ntem province, the country's health minister said on Monday.

The World Health Organization (WHO) confirmed the outbreak in the small Western African country . "Further investigations are ongoing. Advance teams have been deployed in the affected districts to trace contacts, isolate and provide medical care to people showing symptoms of the disease," the WHO said in a statement.

What is known about the outbreak?

According to the WHO, so far nine deaths and 16 suspected cases have been reported. Symptoms so far have included fever, fatigue, as well as blood-stained vomit and diarrhea.

The government of Equatorial Guinea announced last week that it was investigating the cause of several suspected cases of hemorrhagic fever, but said only three people had shown "light symptoms." The affected area was located in a rural eastern region of dense forest near the borders of Gabon and Cameroon.

Health Minister Mitoha Ondo'o Ayekaba said a "health alert" had been declared in the Kie-Ntem province and the neighboring district of Mongomo, with a "lockdown plan implemented" after consulting with the WHO and the United Nations.

How deadly is Marburg virus?

The Marburg virus is part of the so-called filovirus family that also includes the Ebola virus, which has wreaked havoc in several previous outbreaks on the African continent.

It is a highly dangerous pathogen that causes severe fever that often includes bleeding. The virus frequently targets several organs and reduces the body's ability to function on its own. 

There are no authorized vaccines or drugs to treat Marburg, but rehydration treatment to alleviate symptoms can improve the chances of survival. Depending on the strain and case management, the fatality rates for the virus range from 24% to 88%.

During an outbreak in Angola in 2004, the virus killed 90% of the 252 people who were infected. In Ghana last year, two people died of Marburg.

Why is it called Marburg virus?

The rare virus was first identified in 1967 after it caused simultaneous outbreaks of disease in laboratories in Marburg, Germany and Belgrade, Serbia.  Seven people died who were exposed to the virus while conducting research on monkeys.

The natural carrier of the Marburg virus is the African fruit bat, which carries the virus but does not fall sick from it.

But the animals can pass the virus to primates in close proximity, including humans. Human-to-human transmission then occurs through contact with blood or other bodily fluids.

dh/rs (AFP, AP, Reuters)