The number of confirmed , probable and suspected cases of Ebola in the current outbreak has surpassed 16,000 , according to the World Health Organization , with nearly 7,000 deaths from those cases . The United Nations ' health agency issued its latest numbers Friday , focusing on how Ebola has affected Guinea , Liberia and Sierra Leone -- the three countries where the vast majority of cases have occurred . Liberia has been hit hardest , with the WHO reporting 7,244 confirmed and potential cases as well as 4,181 deaths . Both numbers reported Friday are significantly higher than those released earlier in the week . The WHO and other health agencies have long said the scale of the Ebola outbreak is likely significantly worse than even the current high numbers indicate , because many people died before they could be diagnosed and many contracted the disease in remote areas without ready access to health care . The U.N. health agency recently noted that the situation in Liberia has stabilized in the past five weeks , after the rate of new cases declined from mid-September through mid-October . The one country where WHO has reported a significant uptick -- with 385 new confirmed cases during the week of November 23 and 533 in the previous week -- is Sierra Leone . Ebola and similar contagious diseases are not new to Africa , but the latest outbreak has been particularly virulent and deadly . About 60 % of those infected have died from the virus , according to WHO . The rapid infection rate fanned concerns that , due to the relative ease of international travel , Ebola might spread outside the continent . In fact , there have been new cases of Ebola in the United States and Spain , though such incidences remain a tiny fraction of the overall outbreak . The United Nations has urged countries worldwide to pitch in , asking in September for nearly $ 1 billion to help Guinea , Liberia and Sierra Leone in their efforts to control the deadly disease . While experimental drugs and treatments have been used to treat Ebola , there 's no known vaccine that can prevent the disease . Earlier this week , the U.S National Institutes of Health reported on the first human trial on one vaccine that 's being fast-tracked by that government agency and British pharmaceutical giant GlaxoSmithKline . Researchers tested the blood of 20 volunteers -- all healthy adults between the ages of 18 and 50 who got the vaccine -- at two weeks and four weeks after they first got their shots to determine if anti-Ebola antibodies had been produced . All developed such antibodies within four weeks of receiving the vaccine , with levels higher in those who were given the higher-dose vaccine . Scientists : 'Positive ' results in 1st human trial of experimental Ebola vaccine . Doctor 's condition worsens . A number of the cases of Ebola outside of West Africa are of health workers who treated patients . In Italy , one doctor who contracted Ebola while treating Ebola patients in Sierra Leone has seen his condition deteriorate , according to the Lazzaro Spallanzani National Institute for Infectious Diseases . The doctor , whose name has not been revealed , had arrived in Rome from Sierra Leone on Tuesday on a special bio-containment military plane . His condition was initially stable , but has become worse since Friday , the medical institute said , and has been suffering from major gastrointestinal disorders . The Italian doctor was working for the Italian aid organization , Emergency , and had treated Ebola patients in Sierra Leone . It is not clear how he contracted the virus , the aid organization said .
The World Health Organization reports nearly 7,000 Ebola deaths . The vast majority of cases have been in Guinea , Liberia , Sierra Leone . About 60 % of those infected have died from Ebola , WHO estimates .