The UN health agency reported that as of December 20, 19,340 people had been infected with the deadly virus in Guinea, Liberia and Sierra Leone, and that 7,518 of them had died.
The death toll in other countries remained the same: six in Mali, one in the United States and eight in Nigeria, which was declared Ebola-free in October.
Spain and Senegal, which have both been declared free of Ebola, meanwhile counted one case each, but no deaths.
Four days earlier the toll stood at 8,759 cases and 2,477 deaths.
Liberia, long the hardest-hit country, has seen a clear decrease in transmission over the past month.
As of December 18, the country counted 7,830 cases and 3,376 deaths, up from the 7,819 infections and 3,346 deaths recorded in the previous update.
In Guinea, where the outbreak started a year ago, 2,571 Ebola cases and 1,586 deaths were recorded as of December 20.
The previous tally showed the country with 2,453 Ebola cases and 1,550 deaths.
