When Ebola lingers: A survivor's story
There are at least 17,000 Ebola survivors currently facing a very uncertain future.
The case of British nurse Pauline Cafferkey, who remains in a serious but stable condition in hospital in London, is a timely reminder of how little is known about the lingering after effects of the killer virus.
The World Health Organization says there's only one other well-documented Ebola survivor who has suffered severe complications after recovering from the virus, American infectious disease expert Dr Ian Crozier.
He was originally infected in September 2014 while treating patients in Sierra Leone. He was sent back to the US to receive treatment in a special Ebola unit in Atlanta. He left the hospital in October, after being given the all clear.
"I walked out of the isolation unit in Atlanta a very different person," Dr Ian Crozier tells me from his family's home in Arizona.
"I returned to Pheonix, where my family was, and began the long process of reattaching to life.
"I was very fortunate to be alive."
But a new, unexpected challenge awaited Dr Crozier, as it did the thousands of Ebola survivors in affected West African countries.
"I quickly realised it wasn't over," he says.
"I began to struggle with severe joint pains, muscle pain and stiffness. I suffered profound fatigue, and I lost the hearing in my left ear."
There was worse to come.
A couple of months after his initial recovery, Dr Crozier's left eye became extremely painful and inflamed.
He returned to the Emory University hospital, where medics used a tiny needle to withdraw fluid.
To their astonishment, the inside of Dr Crozier's eye was "teeming" with the virus.
Dr Crozier says: "We found hundreds of millions of copies [of the virus]. It was active, multiplying Ebola virus."
His eyeball became soft, and he temporarily went blind in his left eye.
At one point, his eye temporarily changed colour, from blue to green.
"It was quite shocking," he says.
"I was terrified of potentially spreading the virus to my family through my tears."
But tests quickly revealed fluids on his eye, and his tears did not contain the virus, so he posed no danger to others.
Ebola hitching a free ride
Ebola can persist in "immune privileged sites" - parts of the body immune cells cannot reach - after a patient recovers from their illness.
Recent research published in the New England Medical Journal found Ebola lingered in semen for nine months after men recovered.
But it is unclear whether those men are contagious.
The WHO says the risk of sexual transmission is "probably low", otherwise there would be far more new infections.
As well as the inner eyeball and semen, other immune privileged sites include the central nervous system, breast milk and the placenta.
Dr Crozier says: "You take it very personally.
"In a sense, this virus was hitching a free ride for months and months. That was difficult to come to terms with.
"Many of us [survivors] are angry and indignant that the virus is persisting."
Expect the unexpected
There have been a number of reports of people experiencing eye problems in affected West African countries.
However, unlike in Dr Crozier's case in the US, and Pauline Cafferkey's case in the UK, most of those experiencing these sorts of problems are not investigated rigorously, so data and evidence about what is going on is scarce.
Dr Crozier describes life after Ebola as a kind of balancing act of being grateful to be alive, but acutely aware of the uncertainty.
"That tension is much more pronounced for the West African survivors." he says.
"This virus is the chief of home-wreckers.
"Many lost their entire families and are now facing these problems, as well as stigma in their communities, when they thought the worst of it was over."
Dr Crozier says his health and eyesight is improving, but he is not entirely better. "I've continued to struggle with joint pains, hearing loss and fatigue."
As Pauline Cafferkey continues her second fight for life because of Ebola, Dr Crozier says he and many other survivors stand alongside the British nurse and her family.
"We're all learning. This virus is teaching us as we go along," he says.
"I've learned to take nothing off the table in terms of what we know or what we think we know about Ebola.
"You become resilient and prepared for the unexpected."