The World Health Organization said that Ebola cases in Guinea and Sierra Leone are still in large numbers, though " less severe," BBC reported.

Quoting the World Health Organization (WHO) Director General Margaret Chan,she said, "cases in Guinea and Sierra Leone were 'less severe" than a couple of months ago, but she said "we are still seeing large numbers of cases".

Close to 6,600 people have died from the virus, WHO's latest data showed. The report stated that as of Dec. 10, data showed of 18,188 cases with the infection mostly affecting Guinea, Liberia and Sierra Leone.

Other countries affected by the virus are Mali, United States, Nigeria,Spain and Senegal.

However most of the countries which had reported cases are now Ebola-free, such as Nigeria and Senegal.

Sierra Leone has 8,069 cases and 1,899 deaths on December 10.Liberia, as December 7, have 7,765 cases and 3,222 deaths.

Chan meanwhile said that although the risk of the virus is always there, there seems to be a more improved containment of the outbreak.

 "In Liberia we are beginning to see some good progress, especially in Lofa county [close to where the outbreak first started] and the capital," Chan was quoted as saying.

 Adding "It's not as bad as it was in September. But going forward we are now hunting the virus, chasing after the virus. Hopefully we can bring [the number of cases] down to zero."

WHO web site described Ebola as a" severe acute viral illness often characterized by the sudden onset of fever, intense weakness, muscle pain, headache and sore throat. This is followed by vomiting, diarrhea, rash, impaired kidney and liver function, and in some cases, both internal and external bleeding."

There is no known cure for Ebola but scientists are conducting experimental testing to find the drug or vaccine for the virus.