The WHO said that as of October 12, 4,493 people have died from Ebola out of a total of 8,997 registered cases in seven countries.
The last official WHO toll, valid to October 8, put the figures at 4,033 dead from 8,399 cases.
The seven countries are split into two groups by WHO. The first includes Guinea, Liberia and Sierra Leone -- by far the worst-affected nations.
The second includes Nigeria, Senegal, Spain and United States, which have seen a small number of highly isolated cases.
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Guinea, where the epidemic originated in December, has seen 1,472 cases and 843 deaths.
Health workers continue to pay a heavy price as they battle the epidemic, with 236 deaths out of 427 cases across the countries.
A total of 96 health workers have died in Liberia, 95 in Sierra Leone, 40 in Guinea, and five in Nigeria.
Nigeria's overall toll remained unchanged at eight dead from 20 cases. WHO has said it will be declared Ebola-free on October 20 if it has no further cases.
The toll remained unchanged in Senegal with one case.
In the Democratic Republic of Congo, hit by a separate strain of Ebola from the one raging in west Africa, the WHO said there have been 71 cases and 43 deaths up to October 7.