Ebola virus disease (or Ebola haemorrhagic fever, as it is formerly known) is a highly contagious, often fatal, viral disease.
It is a relatively modern condition. According to the World Health Organisation (WHO), the first recorded cases appeared in 1976, when there were simultaneous outbreaks in two regions of Africa: Nzara, Sudan and Yambuku, Democratic Republic of Congo.
The virus was named after the Ebola river, which runs through the village of Yambuku.
What are the symptoms of Ebola?
Within two to 21 days of contracting the virus, people infected with Ebola will initially develop symptoms including: a fever, intense weakness, muscle pain, a headache and a sore throat.
As the illness progresses these symptoms develop into vomiting, diarrhoea, rashes, impaired kidney and liver function and in some cases internal and external bleeding.
During outbreaks, nine in 10 people die from the virus.
How is Ebola spread?
People can become infected if they come into close contact with the blood, organs or bodily fluids of animals harbouring the disease. Common ways of coming into contact with the virus include the consumption of infected milk or under cooked meat.
Animals which have spread the disease in Africa include fruit bats, primates, monkeys, forest antelope and porcupines.
Ebola can also be spread from person to person when contact is made with an infected person's broken skin, mucus membranes or bodily fluid (eg. saliva, sweat, urine or blood).
It can also be spread through indirect contact with such fluids - for instance from drinking from a cup previously used by an infected person.
The virus can be sexually transmitted. Men who have recovered from the disease can have contagious sperm for up to seven weeks.
How is Ebola treated?
There is no known cure for Ebola. People who contract the virus must be treated in intensive care and given plenty of fluids to prevent dehydration and kept in isolation to prevent further spread of the disease.
No specific treatment is yet available, but new drugs are being tested.
Is there a vaccine?
Ebola vaccines are being tested, but none are currently available.
More on Parentdish: Could Ebola spread to the UK?