The death toll in the world's worst-ever Ebola epidemic has edged closer to 3,900, with the virus killing nearly half of the more than 8,000 people infected, UN figures showed Wednesday.

In its latest update on the epidemic, the World Health Organization said that a total of 8,033 people had been infected across five west African countries and the United States.

Of those, 3,865 had died, it said.

With the count running up to October 5, the figures did not include the Spanish nurse confirmed on Monday as having Ebola, the WHO underlined.

She is the first case of transmission outside Africa, having cared for two elderly Spanish missionaries who died from the virus following their return from west Africa.

Nor did the death tally include the Liberian man who died Wednesday in a US hospital, who was the first person diagnosed with Ebola outside of Africa.

Latest toll figures

Here are the latest WHO numbers up to October 5:

In Guinea, where the began late last year, Ebola had infected 1,298 people, killing 768 of them.

In Liberia, the hardest-hit country to date, 3,924 people had been infected with Ebola and 2,210 of them had died.

In Sierra Leone, Ebola had infected 2,789 people and killed 879 of them.

Nigeria had recorded 20 cases, including eight deaths, since Ebola first arrived in the country with a Liberian finance ministry official, who died in Lagos on July 25.

The last case confirmed in the country was on September 5.

Senegal's only confirmed Ebola case—a Guinean student who crossed the border just before it was closed on August 21—has recovered, but the country will not be declared free of the virus until 42 days after the case was recorded.

The United States has seen one confirmed case, the Liberian who died Wednesday.

Healthcare workers

Healthcare workers, already in very short supply in the impoverished countries hardest-hit by the outbreak, have paid an especially heavy price. As of October 5, 401 had been infected across four west African countries and 232 had died.

Guinea: 73 healthcare workers infected, 38 of whom died.

Liberia: 188 infected, with 94 deaths.

Sierra Leone: 129 infected, with 95 deaths.

Nigeria: 11 healthcare workers infected, with five deaths.

Separate outbreak

The Democratic Republic of Congo has meanwhile been struck by a separate Ebola outbreak. Up to October 5, the disease had killed 43 of the 70 people infected there. Eight of the dead were .

Five Ebola species

There are five known distinct species of Ebola and the outbreak in west Africa stems from the Zaire species—the deadliest of all.

That species caused the world's first known Ebola outbreak in 1976 in Zaire—now known as the Democratic Republic of Congo, had been the deadliest on record, with 280 deaths.

© 2014 AFP