Global health experts on Friday declared the Ebola epidemic ravaging West Africa an international health emergency that requires a coordinated global approach . Guinea , Liberia and Sierra Leone are battling the Ebola virus , which has also spread to Nigeria . The virus has killed 961 people from the start of the outbreak this year through Wednesday , the World Health Organization said . `` The possible consequences of further international spread are particularly serious in view of the virulence of the virus , the intensive community and health facility transmission patterns , and the weak health systems in the currently affected and most at-risk countries , '' WHO said Friday after two days of emergency meetings . The U.N. health agency described it as the worst outbreak in the four-decade history of tracking the disease . `` A coordinated international response is deemed essential to stop and reverse the international spread of Ebola , '' WHO said . Ebola virus : 9 things to know about the killer disease . Medical aid groups applauded the designation but said that it alone wo n't reduce fatalities . `` Declaring Ebola an international public health emergency shows how seriously WHO is taking the current outbreak , but statements wo n't save lives , '' said Dr. Bart Janssens , director of operations for Doctors Without Borders , a humanitarian organization . `` Now we need this statement to translate into immediate action on the ground . For weeks , MSF has been repeating that a massive medical , epidemiological and public health response is desperately needed to save lives and reverse the course of the epidemic , '' said Janssens , using the initials for his organization 's French name , Medecins Sans Frontieres . `` Lives are being lost because the response is too slow . '' The agency said it has nearly 700 staff responding to the crisis in the affected countries . `` All our Ebola experts are mobilized , we simply can not do more , '' Janseens said . American patients improving . Two Americans who contracted Ebola while supporting efforts to fight the disease in Liberia are showing improvement at Emory University Hospital in Atlanta . Dr. Kent Brantly and aid worker Nancy Writebol are getting treatment at one of four U.S. institutions capable of providing such treatment . WHO warns of bogus information . Meanwhile , a WHO official said bogus information is adding to the rapid spread of the disease . `` Perhaps one of the most important factors contributing to this is fear and misinformation , '' said Dr. Keiji Fukuda , assistant director for health security . `` This is critical to understand , because what it is doing is that it helps foster suspicion and anxiety in communities , and when that happens we see a situation where people are reluctant to go to health facilities or maybe reluctant to bring their family members there . '' Though infectious , Ebola `` is not mysterious '' and can be contained , Fukuda said . Liberian President Ellen Johnson Sirleaf said the fast-spreading disease has overwhelmed her nation 's health care system . `` The scope and scale of the epidemic ... now exceed the capacity and statutory responsibility of any one government agency or ministry , '' she said . The Liberian leader declared a 90-day state of emergency this week , which will allow her government to set up a series of measures to prevent the spread of the disease . 9 questions about this new Ebola drug . While Liberia struggles to contain the epidemic , the United States ordered relatives of its embassy employees to leave the country . The U.S. Embassy is in the capital of Monrovia , one of the areas hardest-hit by the epidemic . Washington said it 's sending experts to Liberia , including 12 specialists from the Centers for Disease Control and Prevention , and a 13-member disaster assistance response team from the U.S. Agency for International Development . Ebola is here : 5 reasons not to panic . The Ebola virus causes hemorrhagic fever that affects multiple organ systems in the body . Early symptoms include weakness , muscle pain , headaches and a sore throat . They later progress to vomiting , diarrhea , impaired kidney and liver function -- and sometimes internal and external bleeding . Ebola spreads through contact with organs and bodily fluids such as blood , saliva , urine and other secretions of infected people . It has no known cure . The most common treatment requires supporting organ functions and maintaining bodily fluids such as blood and water long enough for the body to fight off the infection . What 's the risk of catching Ebola on a plane ?
Ebola has killed 961 people from the start of the outbreak this year . The WHO says there is no vaccine or cure for Ebola, but it can be treated with supportive care and proper hygiene. Doctors Without Borders applauds designation but says `` statements wo n't save lives ''