As the death toll from Ebola reaches 670, a second Amercian doctor contracts the virus in Liberia, and it is feared to have spread to Nigeria, here's an explanation of what Ebola is, how it is spread, and how worried we should be
The World Health Organisation says Ebola is one of the most virulent viral diseases known to humankind, causing death in 50 to 90 percent of all clinically ill cases
What is Ebola?
Ebola virus disease (EVD), formerly known as Ebola haemorrhagic fever, is described by the World Health Organisation (WHO) as "a severe, often fatal illness in humans."
It first appeared in 1976 in two simultaneous outbreaks - in Nzara, Sudan; and in Yambuku, in the Democratic Republic of Congo. The latter was in a village situated near the Ebola River, from which the disease takes its name. It is mainly found in tropical Central and West Africa, and can have a 90 per cent mortality rate - although it is now at about 60 per cent.
Ebola virus disease (EVD), formerly known as Ebola haemorrhagic fever, is described by the World Health Organisation (WHO) as "a severe, often fatal illness in humans."
It first appeared in 1976 in two simultaneous outbreaks - in Nzara, Sudan; and in Yambuku, in the Democratic Republic of Congo. The latter was in a village situated near the Ebola River, from which the disease takes its name. It is mainly found in tropical Central and West Africa, and can have a 90 per cent mortality rate - although it is now at about 60 per cent.
How is it transmitted?
The virus is known to live in fruit bats, and normally affects people living in or near tropical rainforests.
It is introduced into the human population through close contact with the sweat, blood, secretions, organs or other bodily fluids of infected animals such as chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest.
The virus then spreads in the community through human-to-human transmission, with infection resulting from direct contact (through broken skin or mucous membranes) and indirect contact with environments contaminated with such fluids.