A British nurse who was twice successfully treated after contracting Ebola in Sierra Leone in 2014 was on Tuesday admitted to a special isolation ward in London for a third time, health officials said.

Pauline Cafferkey, who voluntarily went to the west African country to treat Ebola patients, was initially admitted to a hospital in Glasgow and later transferred to the Royal Free Hospital.

She was flown from Glasgow to London in an isolation bed on a Royal Air Force (RAF) Hercules military transport plane.

“We can confirm that Pauline Cafferkey is being transferred to the Royal Free Hospital due to a late complication from her previous infection by the Ebola virus,” the clinic said in a statement.

“She will now be treated by the hospital’s infectious diseases team under nationally agreed guidelines.”

“The Ebola virus can only be transmitted by direct contact with the blood or bodily fluids of an infected person while they are symptomatic so the risk to the general public remains low,” it added.

Cafferkey was treated twice at the Royal Free Hospital, Britain’s only isolation ward for the lethal disease, after suffering an “unusual complication” of her first infection.

Cafferkey was diagnosed with Ebola in December 2014 after returning to Glasgow from Sierra Leone.

She suffered a relapse in October 2015, when the virus caused her to become critically ill with meningitis before she made a full recovery.

“It is very sad to hear that Ms Cafferkey has once again been admitted to hospital,” said Derek Gatherer from Lancaster University.

“The meningitis that Ms Cafferkey suffered from at the end of last year is one of the most serious complications of all, as it can be life-threatening.  

“She was unlucky enough to be one of only a handful of patients in whom it has been seen,” he added.

The deadliest-ever Ebola outbreak since the virus was identified in central Africa in 1976 has killed 11,316 of the 28,639 people infected since December of 2013, according to the latest WHO figures.

Nearly all the victims have been in Guinea, Liberia and Sierra Leone.