Pauline Cafferkey

Nurse Pauline Cafferkey is now at the Queen Elizabeth University Hospital in Glasgow. She initially recovered from the Ebola hemorrhagic fever and was sent home in January last year. (Reuters)

A Scottish nurse, who recovered from Ebola but then suffered life-threatening complications from the virus persisting in her brain, has been admitted to hospital for a third time, a hospital in Scotland said on Tuesday.

Pauline Cafferkey contracted Ebola in December 2014 when she was working in a treatment facility in Sierra Leone at the height of an epidemic of the disease which swept through three countries in West Africa.

Cafferkey was admitted to Queen Elizabeth University Hospital in Glasgow, Scotland's biggest city, and was transferred to London's Royal Free Hospital.

"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. She will now be treated by the hospital's 
infectious diseases team under nationally agreed guidelines," Royal Free Hospital said in a statement on Tuesday. 

Cafferkey initially recovered from the Ebola hemorragic fever and was sent home in January last year.

But in October she fell ill again and doctors found the virus was persisting in tissues in her brain. They later said she had developed meningitis caused by the Ebola virus — the first known such case.

She was treated with an experimental antiviral drug known as GS5734 being developed by U.S. drugmaker Gilead Sciences, although doctors did not disclose whether they thought the drug had improved her condition. She was discharged from the Royal Free Hospital in London in November.

The World Health Organization says in rare instances, Ebola can persist in parts of the body not covered by the immune system, including inside the eye, the brain, the spinal cord or in semen.

WHO spokeswoman Fadela Chaib said Ebola survivors need "comprehensive support" to minimize the risk of further spread, especially via sexual transmission — which has been blamed for some recent flare-ups of Ebola in West Africa.

Scientists said while many patients suffer long-term side effects, Cafferkey's case is unusual.

"It is difficult to know what the likelihood of further relapses are, given the previous unprecedented nature of her situation," said Dr. Nathalie MacDermott, a clinical research fellow at Imperial College London.

Experts have previously suggested that Ebola relapses might be triggered by the immune system, when the body gets distracted fighting another infection. That could give any persistent virus a chance to start replicating.

It's still unclear whether any lingering Ebola might be responsible for survivors' ongoing medical problems or if those can
be blamed on the acute illness that patients recovered from earlier.

Among the thousands of Ebola survivors in West Africa, many still suffer painful side effects including problems with their joints, eyes and ears.

To date, Ebola has killed more than 11,000 people in West Africa

With files from The Associated Press