Ebola survivor infected years ago may have started new outbreak
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A man sitting last week in front of a hut containing the ashes of his late mother and other victims who died of Ebola in Liberia, West Africa.
PHOTO: EPA-EFE
NEW YORK • An Ebola outbreak now occurring in Guinea was almost certainly started by someone who survived West Africa's historic 2014-16 epidemic, harboured the virus for at least five years and then transmitted it via semen to a sex partner, researchers say.
The finding reported on Friday was based on genetic sequencing of virus samples taken from patients in the current outbreak, and shocked researchers.
Until now, the longest the virus had been known to persist in a survivor was 500 days.
"It's a stunner," Dr William Schaffner, an infectious-disease expert at Vanderbilt University who was not involved in the research, said in an interview.
"This is an extraordinary phenomenon."
The current outbreak in Guinea was first recognised in January and has infected at least 18 people and killed nine.
The discovery that a survivor most likely started the outbreak has profound implications. West Africa's previous epidemic infected more than 28,000 people, killed more than 11,000 and left thousands of survivors, some of whom were already being shunned because of fears about the disease.
The prospect that those who survived might be infectious for years is likely to worsen their plight.
The new finding also raises the possibility that other outbreaks in the region, assumed to have begun with transmission from animals, may actually have been started by survivors with unrecognised, lingering infections.
One possible solution, Dr Schaffner said, would be "to vaccinate much of equatorial Africa" against Ebola even where there is no current outbreak. There are effective vaccines available, one made by Merck and another by Johnson & Johnson, but so far they have generally been used only in response to outbreaks.
People recover from Ebola when their immune systems wipe out the virus.
But certain parts of the body, including the eye, the central nervous system and the testes are so-called privileged sites, beyond the reach of the immune system.
The virus can sometimes hide in those spots.
But no one knew it could hide out for so long.
"We have no idea how often this may be happening," Dr Schaffner said.
"Some studies are under way. As you can imagine, it's not easy to study hiding viruses in immunologically privileged sites, like the testicles, the eye and, rarely, the central nervous system. Those are not accessible places for easy study."
Genetic sequences of virus samples from the current patients were compared to those from the 2014-16 outbreak and were found to be so similar that they had to be closely related, researchers said.
NYTIMES
