Oct. 14, 2015 -- Pauline Cafferkey, the Scottish nurse who survived the Ebola virus and was thought to have made a full recovery, is now critically ill, officials say.
Cafferkey, 39, was discharged from the high-level isolation unit at London's Royal Free Hospital in January, but she's now back there receiving treatment for what doctors say is an "unusual late complication of her previous infection by the Ebola virus."
She became ill last week, but her family says an after-hours doctor sent her home rather than referring her to a specialist for treatment.
Cafferkey had gone back to work as a nurse, and last week was presented with a Daily Mirror Pride of Britain award on behalf of the British Ebola aid effort by Samantha Cameron, wife of the British prime minister.
"My thoughts with this brave & inspiring woman. Wishing her strength at this time,” tweeted Nicola Sturgeon, head of the Scottish government.
"We know that Ebola can linger for many months after visible symptoms have cleared,” says Jonathan Ball, a professor of molecular virology at the University of Nottingham in Britain. “We also know from outbreaks in the past that survivors can show a variety of symptoms, and the debilitating effect of these can last for a very long time.
"But this is frankly staggering. I am not aware from the scientific literature of a case where Ebola has been associated with what we can only assume as life-threatening complications after someone has initially recovered, and certainly not so many months after."
Dr. Nathalie MacDermott, a clinical research fellow at the Imperial College London, adds: "This is an unprecedented situation in medical terms and an uncertain time for Pauline and her family.
"The change in her condition does not imply any increased risk to the general public, as stated previously the risk to the general public who may have had contact prior to her deterioration remains extremely low.
"It is unlikely that anything could have been done to prevent this relapse; this is an unexpected situation which could not have been anticipated. It is difficult to know whether any earlier intervention may have altered her current condition, as we are only just learning about the potential long-term effects of Ebola virus disease and management of complications/secondary effects."
Cafferkey caught the disease while working for the international charity Save the Children at a treatment center in Kerry Town, Sierra Leone. She became ill after returning to the United Kingdom.
She was the second person from the U.K. to recover from Ebola during the recent outbreak. British volunteer nurse William Pooley was treated in the same special unit after also being infected while working in Sierra Leone.
The Royal Free Hospital has an isolation unit and infection-control protocols with specially trained staff ready to deal with Ebola cases.
Experts say the risk of catching Ebola from another person is low. The virus is spread by direct contact with the blood or body fluids while an infected person has symptoms.
The Ebola outbreak in West Africa appears to have receded. For the first time since March 2014, the World Health Organization says no confirmed cases of Ebola were reported during the week of Oct. 4.
There are still no fully approved vaccines or treatments against Ebola, though some trials have shown promising results.
Ebola Remains in the Body
It was already known that the Ebola virus can live on for a long time in certain parts of the body like the eye even after it is undetectable in the person's blood.
The Ebola virus can shelter in what are known as “immune privileged sites” in the body, including the eyes, central nervous system, and testicles.
Men who have had Ebola are advised to abstain from sex or to use condoms, as the virus can be spread through semen.
Although the risk of Ebola survivors passing on the virus appears to be low, some experts are concerned that the many survivors in West Africa could trigger further outbreaks if they become unwell again.