What is Ebola?
Ebola virus disease (also known as Ebola hemorrhagic fever), along with being one of mankind's deadliest diseases, is also one of its most brutal. It causes extreme body aches, high fever, heavy internal and external bleeding, profuse vomiting and diarrhea - all of which contain high concentrations of infectious virus.
Symptoms can manifest themselves between two and 21 days after exposure and usually begin with headaches and fever. There is no cure for the disease, which has been fatal in up to 90 percent of patients during some
outbreaks, though the current outbreak has killed about 60 percent of those so far infected. Treatments include managing the patient's fluids and electrolytes, as well as blood pressure, all of which are in jeopardy as the infected bleed out of organs and even blood vessels.
Transmission of the virus occurs when a person comes into contact with the bodily fluids - blood, vomit, feces -
of an infected person. This puts health workers tending to Ebola patients in an extremely dangerous position as patients can throw off huge amounts of their fluids during painful, uncontrollable fits of pain and vomiting. Walls, sheets and medical equipment often become soaked in the highly contagious fluids. Patients are kept in isolation wards to avoid infecting others in a clinical setting.
Even with the full body suits health workers wear - the iconic image of the disease - transmissions occur. Several American missionaries working to disinfect doctors and nurses operating in suits have contracted Ebola and the chief doctor fighting the outbreak in Sierra Leone, Dr. Sheik Umar Khan, caught the virus and died.
The first diagnosed case of the Ebola Zaire strain was a nurse who perished after treating a nun who broke with the disease after helping treat the sick in then Zaire.
There are five known strains of Ebola, which first manifested itself in humans in the 1970s in Zaire and Sudan. Four of the five have caused disease in humans, while the fifth, Ebola Reston, caused disease only in primates. The Reston strain is named for Reston, Virginia where the strain was discovered in a commercial monkey house in 1989. It killed hundreds of monkeys, and many more were euthanized, but never made the jump to human beings.
How it spreads
In Nigeria, which had an imported case of the virus in a Liberian-American who flew to Lagos this week, authorities will have to trace all passengers and anyone else he may have crossed paths with to avoid the kind of spread other countries in the region have suffered.
Africa outbreak, which began in Guinea in February, has already spread to Liberia and Sierra Leone. With more than 1,300 cases and over 729 deaths, it is the largest since the Ebola virus was discovered almost 40 years ago.
Sierra Leone has declared a state of public emergency to tackle the outbreak, while Liberia is closing schools and considering quarantining some communities.
Some in the nations effected by Ebola are distrustful of of authorities battling the disease, thinking it might be caused by those treating it, or that traditional medicinal methods will be better than jam-packed isolation wards -
quite literally - dripping with the virus.