The Ebola outbreak in West Africa has now killed more than 5,000 people, the World Health Organisation (WHO) has said, marking another grisly toll in the epidemic.

This is the largest Ebola outbreak ever recorded, with more than 14,000 people sickened, the vast majority in the West African countries of Liberia, Guinea and Sierra Leone.

There are some signs that the rate of new infections may be slowing overall in Guinea and Liberia, but there are still areas of those countries where transmission remains high, and they are surging in Sierra Leone, the health agency said on Wednesday.

While the response to Ebola is ramping up, it is still insufficient: In Sierra Leone, for instance, less than 40 percent of cases are in isolation, according to WHO estimates.

Worryingly, the virus has continued to pop up in new places, both within the most affected countries and outside their borders. The most recent example is a new Ebola cluster that Malian authorities reported on Wednesday - an alarming setback as the country tries to limit the epidemic ravaging other West African nations.

Mali death

A nurse working at a clinic in the Malian capital Bamako died on Tuesday, and tests later showed she had Ebola, Communications Minister Mahamadou Camara said. Two other people are also believed to have died of Ebola, though no tests were ever done on them to confirm the disease: an imam, whom the nurse treated at the Bamako clinic, and a friend who came to visit the man there.

The announcement of the new cases came just a day after Malian health authorities said there had been no other reported cases - let alone deaths - since a two-year-old girl who had travelled to Mali from Guinea succumbed to the virus in late October.

At least 75 people are under quarantine following the new cases in Bamako, including patients and staff from the hospital, said Ousmane Doumbia, secretary-general for the Malian health ministry. Several of the patients under quarantine are troops serving in the country's UN peacekeeping force who were being treated for wounds at the clinic, the force said in a statement.

Health officials are also searching the city of about 2 million for those who helped prepare the body of the imam for burial before it was known that the corpse might be highly contagious.

Source: Agencies