A nurse who is being treated for a late complication of an Ebola infection is now "critically ill" after her condition "deteriorated", the hospital treating her has said.
Pauline Cafferkey, 39, was admitted to the isolation unit at the Royal Free Hospital in north west London on Friday after becoming unwell in Glasgow.
A statement from the Royal Free said: " We are sad to announce that Pauline Cafferkey's condition has deteriorated and she is now critically ill.
"She is being treated for Ebola in the high level isolation unit at the Royal Free Hospital."
Ms Cafferkey was flown from Glasgow to an isolation unit at the Royal Free Hospital in Hampstead in a military aircraft in the early hours of Friday morning.
She had become unwell earlier in the week and was treated at the Queen Elizabeth University Hospital in Glasgow before being transferred.
A total of 58 close contacts of the nurse have been identified, with 40 of those offered vaccinations as a precaution.
Officials confirmed 25 of them accepted the vaccine while 15 have either declined or were unable to receive it due to existing medical conditions.
The 58 people are a mixture of healthcare workers and friends, family and community contacts.
Ms Cafferkey, who is from South Lanarkshire, was diagnosed with Ebola in December after returning to Glasgow from Sierra Leone via London.
She spent almost a month in an isolation unit at the Royal Free before being discharged in late January.
Scientists agree that b odily tissues can harbour the Ebola infection months after the person appears to have fully recovered.
Ms Cafferkey's family have claimed doctors "missed a big opportunity" to spot she had fallen ill with Ebola again.
Her sister Toni Cafferkey said the way she had been treated was "absolutely diabolical". She said Ms Cafferkey had gone to a GP out-of-hours clinic at the Victoria Hospital in Glasgow on Monday night but the doctor who assessed her diagnosed a virus and sent her home.
Ms Cafferkey contracted Ebola while working as a nurse at the Save the Children treatment centre in Kerry Town.
A report from the charity in February said she was probably infected as a result of using a visor to protect her face rather than goggles.
It said she was unable to use the standard protective goggles because she could not get them to fit properly.
Ms Cafferkey's temperature was tested seven times before she flew from Heathrow to Glasgow in December, and she had been cleared for travel.
She was placed in an isolation unit at Glasgow's Gartnavel Hospital after becoming feverish, before being transferred by an RAF Hercules plane to London on December 30.
She was then transferred to the specialist isolation unit at the Royal Free.
Ms Cafferkey won an award at the Pride of Britain Awards in central London on September 28.
She met the Prime Minister's wife Samantha Cameron the following day at Downing Street, alongside other winners.