World Health Organisation Declares Ebola Global Health Emergency Friday Aug 08,2014

The worst-ever outbreak of the Ebola virus, which has killed nearly 1,000 people in West Africa, has been declared a international public health emergency.

An updated death toll released today by the World Health Organisation, accurate as of Wednesday Aug 06,2014

At least 932 people have died in the outbreak, mainly in Guinea, Sierra Leone and Liberia, that has killed around 60% of those infected and has triggered fears it could spread to other continents.

A billboard about the virus in Freetown, Sierra Leone

The World Health Organisation (WHO), which is meeting in emergency session in Geneva, declared the emergency - which emphasises the "public health risk" and the threat of the disease spreading.

Speaking before the decision was made, WHO spokesman Gregory Hartl said: "This outbreak, because of its size and its geographical extent, certainly merits an extraordinary response and we know countries have announced they must take extraordinary measures, so that is understandable from a public health perspective."

The Center for Disease Control and Prevention (CDC) in the US issued its highest alert - Level 1 - in response to the Ebola crisis in West Africa.

In Liberia and Sierra Leone, soldiers in full combat gear were reportedly deployed to the streets to prevent the movement of people from the infected areas.

Ebola virus disease (EVD)

• Symptoms include high fever, bleeding and central nervous system damage
• Fatality rate can reach 90% - but the current outbreak is about 55%
• Incubation period is two to 21 days
• There is no vaccine or cure
• Supportive care such as rehydrating patients who have diarrhoea and vomiting can help recovery
• Fruit bats are considered to be virus' natural host

HOW THE VIRUS SPREADS 

Ebola emerged in 1976 in two simultaneous outbreaks in Sudan and near the Ebola River in the Democratic Republic of Congo, which gave the disease its name.

There are several strains which vary in how dangerous they are to humans, but death rates have reached as high as 90 per cent.

In the current outbreak that is just over 50 per cent.

It is introduced into humans through direct contact with the blood, organs or other bodily fluids of infected animals including fruit bats, which are eaten as a delicacy.

Other species thought to have passed on the virus have included chimpanzees, gorillas, monkeys, forest antelope and porcupines found ill or dead or in the rainforest.

The virus then spreads between humans through direct contact with blood, organs or other bodily fluids of infected people. 

Symptoms include fever, intense weakness, muscle pain, headache and sore throat followed by vomiting, diarrhoea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding.

People are infectious as long as their blood and bodily fluids contain the virus and the incubation period can range between two and 21 days.

Although the disease has no cure, modern medical treatment and quick isolation help hugely to bring the death toll down