More than 13,000 Ebola survivors are an "emergency within the emergency" for the three countries most affected by the epidemic, a clinician working in West Africa said.
Preliminary data suggest that as many as half of the survivors have severe arthralgia, which can be "very debilitating, a very serious problem that can prevent people from going back to work and providing for their families," said Daniel Bausch, MD, of Tulane University School of Public Health and Tropical Medicine in New Orleans, who is part of the World Health Organization clinical care team in West Africa.
Some 25% of survivors have also reported changes in vision and a smaller proportion have uveitis that in some cases can lead to blindness, he said.
Other conditions are more difficult to tally, he said, including the mental health consequences, such as depression and post-traumatic stress disorder. "Some mental health impact is probably almost universal," Bausch said.
"The world has never seen such a large number of survivors," according to Anders Nordstrom, MD, the WHO representative in Sierra Leone. "This is new, both from a medical point of view and from a societal point of view."
Their comments came at the end of a 5-day conference on issues raised by survivors, including their care, research into the disease, and questions of how ethically and practically to use the massive number of samples generated by the epidemic.
"We have learned a lot, but we are gaining -- and we need to gain -- more knowledge," Nordstrom told reporters in a telephone briefing from Freetown, the capital of Sierra Leone, where some 200 experts had gathered for the conference.
A central issue is the care of survivors, many still with severe chronic conditions, Bausch said.
Previous outbreaks have been so small that it was difficult to pin down the consequences faced by survivors, he noted, although "small numbers of case reports" have pinpointed the eye and joint problems.
"This is really the first time that we've had a much clearer vision and, unfortunately, that vision tells us these are not rare problems, that these are very common problems among survivors," he said.
The symptoms will probably fade over time, he told MedPage Today, but studies of survivors of previous outbreaks suggests that such symptoms as joint pain and sleeplessness can last for up to 21 months.
A key research question, he added, is how the virus persists over time. In people with uveitis, for instance, it seems likely the Ebola virus persists in the eye and causes the inflammation, but the pathogenesis of that is not known.
Bausch also said that treatments for Ebola after-effects are symptomatic because there are, as yet, no licensed drugs that target the virus.
Treatment is complicated by the lack of trained medical staff in the region, he said, noting that Sierra Leone has only two ophthalmologists for the entire country. But a WHO-sponsored team from Emory University in Atlanta has recently been working with them to organize mobile eye clinics and practice plans to reach survivors with eye issues.
While data remains preliminary, he said, it appears that survivors whose acute disease was severe also tend to have the most severe after-effects.
In the wake of a recent case in Liberia, which occurred after the country had been declared Ebola-free, there has been concern about sexual transmission of the virus, since it is known to persist in the testes of survivors.
There were few clues to the origin of the Liberian case, a 17-year-old male who first became ill June 21 and later died, and the WHO is considering it to be a separate outbreak from the main epidemic.
A study now under way in Sierra Leone, with about 100 survivors, suggests that Ebola can persist in semen for "hundreds of days," Bausch said, "but that data is preliminary and really needs to be validated."
On the other hand, there is "very little evidence actually of sexual transmission," he said. "We don't think it's impossible but for whatever reason it doesn't seem to be a very frequent occurrence."
Nordstrom noted that in the hard-hit Sierra Leone district of Kenema -- where there are hundreds of survivors -- "we have not seen one single case of sexual transmission."
An increasing concern is what happens when female survivors become pregnant in the wake of Ebola, commented Ali Wurie, MD, a representative of the Sierra Leone government.
Since those who survived Ebola tended to be younger and healthier in the first place than other patients, many of the women are in their childbearing years and so the number of pregnant survivors is increasing in all three of the affected countries, he said.
What's not known is how the mother's previous Ebola disease affects the health of the newborn child, Wurie said.