The Ebola virus, known to lurk in semen for months after recovery, also can stay in the eye for weeks, researchers reported Thursday.
The good news is that it doesn't seem to be in the tears or tissues that could infect others. The bad news is that it can damage vision, the team reports in the New England Journal of Medicine.
"This case highlights an important complication of Ebola virus disease with major implications for both individual and public health that are immediately relevant to the ongoing West African outbreak," Dr. Jay Varkey of Emory University Hospital and colleagues write in their report, which was also presented to a medical meeting in Denver.
The patient was Dr. Ian Crozier, who was infected while helping fight Ebola in Sierra Leone and who spent six weeks recovering at Emory. Crozier, 43, was extremely ill -- he had multiple organ failure, he spent 12 days on a ventilator and had to undergo more than three weeks of dialysis.
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Even as he recovered, he had trouble thinking and walking. "On day 44 of the illness, hemodialysis was no longer required and his mental status had markedly improved, with some residual mild word-finding difficulty," Varkey's team wrote.
Crozier, who only revealed his identity weeks after his recovery, thought he was in the clear. Then his eye started getting red and sore.
He came back to Emory and they treated him for an eye infection. When steroids didn't help, they carefully took some fluid from inside the eyeball -- mindful that it just might contain some virus - and sent it for testing.
Sure enough, the Ebola virus as deep inside Crozier's eye, affecting his vision and causing pain. His vision deteriorated from perfect to 20/400.
The infection eventually resolved with more treatment, but the case is one more illustration that Ebola can leave even its lucky few survivors with long-lasting souvenirs. Other patients say they have joint pain even months after recovery, and there had been some hints that eye trouble and even blindness might plague survivors as well.
In the most troubling case, the last known Ebola patient in Liberia died in March and the only possible known way she could have gotten it seems to have been through sex with her fiancé, an Ebola survivor.
There does not seem to be a way to spread the virus from an infected eye, however, says Varkey.
"It is reassuring that samples of conjunctivae and tears tested negative for Ebola virus, a finding that supports previous studies suggesting that patients who recover from Ebola virus disease pose no risk of spreading the infection through casual contact," they wrote.
Ebola's infected more than 26,000 people in the ongoing West African epidemic and killed 11,000 of them.
This article originally appeared on NBCNews.com.