Ebola no longer dominates the headlines but for an estimated 17,000 survivors of the largest Ebola outbreak in history, the struggle is not over. Many who survived the West African outbreak that sickened nearly 30,000 people between 2014 and 2016 are living with a constellation of long-term symptoms known as post-Ebola syndrome.
Some of those Ebola survivors are right here in Texas. A Fort Worth doctor fell sick with Ebola while working in Liberia and two nurses became infected in Dallas while caring for the first person to be diagnosed with Ebola in the U.S.
One of those nurses, Nina Pham, 28, is suing her then-employer, Texas Health Presbyterian Dallas, and its parent company, Texas Health Resources. Pham says the hospital failed to protect its staff from the Ebola virus. Her case may go to trial as early as next week.
In an exclusive interview with The Dallas Morning News last year, Pham said she suffered hair loss, physical pain, insomnia and nightmares since recovering from Ebola. Doctors who cared for her at the National Institutes of Health in Bethesda, Md. told Pham that some of those symptoms could be a result of the infection.
Little is understood about life after Ebola. Before the 2014 West African epidemic which killed more than 11,000 people, most Ebola outbreaks sickened a few hundred people at most. Researchers rarely went back to follow up on those who survived.
But in the fall of 2014, doctors in West Africa noticed that of the 40 percent of patients who survived Ebola, many were complaining of headaches, joint pains, memory loss and even blindness. Doctors at the World Health Organization found that nearly half of all Ebola survivors in parts of Sierra Leone had vision problems. These symptoms were grouped together as post-Ebola syndrome.
Large-scale studies into the health of Ebola survivors had not been conducted. Until now. Last summer, the first of its kind Ebola survivor study was launched in Liberia. So far, 1,111 people who were infected with Ebola and 2,604 of their friends and family members have enrolled in the study.
Their health will be monitored over the next five years and while all will have general physical exams, some will undergo special eye and neurological tests. Friends and family members of survivors act as controls helping researchers understand which symptoms are part of the aftermath of Ebola and which ailments occur generally among the Liberian population.
The study is being done by the Partnership for Research on Ebola Vaccines in Liberia or PREVAIL, a coalition of scientists from the Liberian Ministry of Health and the U.S. National Institutes of Health.
PREVAIL scientists are working on three major studies. The first study, PREVAIL I, is a clinical trial of experimental vaccines designed to prevent Ebola. PREVAIL II is testing investigational medicines to treat the virus and PREVAIL III is the study of the long term health of Ebola survivors.
So far, researchers have discovered that approximately 1 in 10 survivors suffer an eye disease called uveitis, which is swelling of the middle layer of tissue in the eye wall. That's compared to 1 in 100 of the controls. Left untreated, uveitis can cause scarring, cataracts, glaucoma and blindness. More than a quarter of those who have uveitis have reduced vision, said Bishop.
While many thousands of West Africans may be experiencing these symptoms, one high profile case of uveitis was in Dr. Ian Crozier, an American physician. Crozier contracted Ebola while working in Sierra Leone and was flown to Atlanta for medical care. About two months after he was discharged from Emory University Hospital in Atlanta, Crozier felt pain in his left eye. When he looked in the mirror, his left eye had changed color from blue to green. Eye color can change with uveitis although it's more visible in people with blue and green eyes.
In some survivors, eye disease is manifesting many months after they recover from the infection. "Some people are presenting with eye inflammation a year after they were first sick," said Dr. Rachel Bishop, an ophthalmologist and researcher at the NIH. "I don't want to scare people but you're not out of the woods just because you didn't get eye problems a few months after recovery."
Between 150 and 200 survivors have been recruited to a sub-study that focuses on the health of the nervous system. Commonly seen neurologic symptoms of post-Ebola syndrome are headaches, hallucinations, weakness, muscle pain and memory loss, said Dr. Avindra Nath, a neurologist and scientist at the NIH.
Nath can't say exactly what proportion of survivors experience these symptoms as data are still being analyzed and survivors will be followed up for five years after they join the study. "We're seeing a lot of neurological problems now but it's hard to know if they had similar symptoms when they were first ill," he said.
"I think if you did have neurologic symptoms during the acute illness then you're more likely to have those kinds of symptoms persist." Nath said post-Ebola syndrome can include symptoms such as memory loss, difficulty concentrating, depression and post-traumatic stress disorder.
A lingering virus
Even after Ebola disappears from the blood of a survivor, it can lurk elsewhere in the body. Tissues such as the testes, brain, breasts and joint spaces offer the virus a sanctuary from the immune system.
These precious tissues have evolved ways to protect themselves from the sometimes aggressive reaction of the immune system. That means that while an inflammatory response might surge elsewhere in the body, organs such as the brain and testes can protect themselves from severe swelling. While that's good news for those organs, it's also good news for Ebola which can hide there for months and reactivate later.
This phenomenon could explain why Scottish nurse Pauline Cafferkey has suffered at least two relapses of Ebola since she first recovered in January 2015. Ten months after she was discharged from a London hospital, the nurse fell ill with meningitis caused by a resurgence of Ebola hiding in her spinal fluid. Then in Feburary 2016, she was readmitted to hospital for a complication related to the infection, doctors said.
Nath is keeping a keen eye on Cafferkey's case. "She never had neurological symptoms when she was first ill but then she went into a coma nine months later and then recovered and then had new neurological symptoms affecting her limbs," he said. "That was the reason I was interested in looking at these survivors in Liberia because I want to see, are we going to find that kind of recurrence there?"
Viruses that hide out in these safe places may reactivate at times of stress when the immune system is weakened or conversely, when the immune system is revved up and busy fighting another infection.
Ebola virus has been found in the semen of survivors 18 months after the initial illness, a study published in August found. The eye is another safe hiding spot for Ebola. When Crozier's eye felt painful and changed color, he went straight back to hospital. Doctors inserted a needle into his eye and found more virus in his eyeball fluid than had been in his blood when he was close to death in the ICU weeks earlier.
It hasn't been possible to do that kind of invasive eye testing in Liberia, Bishop said. A lack of testing facilities, equipment and trained healthcare workers prevents her team from running a full barrage of eye tests. But because she has seen survivors develop eye disease a year after their initial illness, Bishop believes the virus can hang out in the eye for at least 12 months.
"We still don't understand the mechanism of what causes the virus to reactivate in the eye", she said. "It's probably connected to how it persists in the testes and the central nervous system - these protected zones."
Crozier, the doctor who saw his left eye change color, has spoken openly about his health since he contracted Ebola. A year after his illness, Crozier developed epilepsy. "I developed my first grand mal seizure in July a few months ago." he said during a meeting at the Food and Drug Administration last year. He said he also suffers hearing loss, fatigue and nerve pain.
Dr. Kent Brantly, a Fort Worth physician, became infected while caring for Ebola patients. Brantly returned to work in Liberia after his recovery and tells reporters there that he doesn't suffer with post-Ebola syndrome. Dr. Craig Spencer, the New York City physician who contracted Ebola in Guinea, told New York Magazine that he was feeling fine nine months after he was sick with Ebola.
Among the Dallas survivors, Pham cannot comment on her current health until after her trial has begun, said her attorney Charla Aldous. Her coworker at Texas Health Presbyterian Dallas, nurse Amber Vinson, has not spoken about her recovery and has not filed a lawsuit.
As with most of the American Ebola survivors, exactly how the Dallas nurses contracted the virus in the first place is unclear. We may never know precisely how or when Pham and Vinson came into contact with Ebola.
More uncertainty and many more unanswered questions lie ahead. While the Ebola survivor study in Liberia is beginning to yield results, it will be another four years before researchers there gather and begin to analyze all of the data.
In the meantime, survivors such as Pham are left to confront their aches and pains. Is that knee pain from Ebola or from a work out? Is a headache a result of dehydration or could the virus still be lurking inside the brain?