The World Health Organization reports the West African country of Guinea is now free of Ebola. This epidemic, the worst in history, has killed more than 11,300 people over the past two years.

FOX's Kate Alexander reports from Geneva:

Guinea begins a 90-day period of heightened surveillance today. WHO Dr. Richard Brennan says this is to make sure that new cases that might emerge are quickly identified before they can spread to other people...

(Brennan) "There is the residual risk of flares due to reemergence of the virus from survivors, but that risk declines with time, because as the survivors do clear the virus from their bodies increasingly over time."

This is the first time since the outbreak of this epidemic two years ago that all three West African countries: Liberia, Sierra Leone, and Guinea, have halted the original chains of transmission that started and drove the Ebola outbreak.

In Geneva, Kate Alexander, FOX News.