British Ebola nurse 'no longer critical'

A British nurse who contracted Ebola while working as a volunteer in Sierra Leone is "no longer critically ill", the London hospital treating her said Monday.

Pauline Cafferkey is showing signs of improvement but remains in isolation, the Royal Free Hospital in London said in a statement.

Cafferkey was diagnosed in Glasgow on December 29 before being transferred to the Royal Free, which has the only isolation ward for Ebola patients in Britain.

She had contracted the disease while working as a volunteer at a British-built Ebola treatment centre in Sierra Leone.

The Ebola outbreak in West Africa has killed nearly 8,300 people with more than 21,000 cases identified since December of last year, according to World Health Organization (WHO) figures.

The vast majority of cases have been in Sierra Leone, Liberia and Guinea.

A total of 838 healthcare workers are known to have contracted the virus and 495 of them had died as of January 4, the WHO has said.