The World Health Organization said the Ebola virus killed 84 people in just three days, bringing the global death toll to 1,229.
The death toll, which passed the 1,000-mark over a week ago, soared higher between last Thursday and Saturday.
The number of confirmed infections jumped by 113 over the three days, bringing the total number of cases to 2,240, the UN health agency said.
The epidemic, which has hit four west African nations since it broke out in Guinea at the start of the year, is by far the deadliest since Ebola was discovered four decades ago in what is now the Democratic Republic of Congo.
Liberia was the hardest-hit country in the latest figures, with 48 new cases and 53 deaths. That lifted its total count of cases to 834, with 466 deaths. The new WHO toll predates an attack overnight Saturday on a quarantine centre in the Liberian capital Monrovia that caused 17 Ebola patients to flee.
Later Tuesday, Liberia's Information Minister Lewis Brown told AFP the 17 patients have been found. "All 17 patients who fled the Ebola centre (on Saturday) have been accounted for. They walked by themselves to the JFK hospital," he said.
Sierra Leone recorded 38 new infections and 17 fatalities, the new WHO data showed. As a result, Sierra Leone's total case count increased to 848 and its death toll to 365. Guinea counted 24 new cases and 14 new deaths. That lifted the total number of cases to 543, with 394 deaths.
Nigeria, meanwhile, recorded three new cases but no deaths. All told, Nigeria has now seen 15 cases and four fatalities, the data showed.