HARI SREENIVASAN: The Ebola outbreak in West Africa has now spread to a fifth country amid forecasts that it will get far worse. The latest case emerged despite efforts to stop the virus from crossing national borders.
The announcement came in Dakar, Senegal, a major tourist destination and transit hub that now has its first case of Ebola.
AWA MARIE COLL SECK, Minister of Health and Social Action, Senegal (through interpreter): It is a young student from Guinea. He came for a consultation on Tuesday, August 26, at the hospital in an infectious state, without hemorrhaging, but hiding the information that he had contact in Guinea with people close to the victims of the disease.
HARI SREENIVASAN: Doctors confirmed the next day the man had Ebola. He’s now in satisfactory condition. Nearly 650 people in his home country of Guinea have been infected and two-thirds have died. That’s the worst death rate of any country.
A new report in “Science” magazine traces the outbreak to a funeral on Guinea’s border with Sierra Leone in May. At least 14 women were infected there. Five local researchers who worked on the paper and collected samples from infected patients have since died of Ebola themselves.
In all, the World Health Organization reports 500 new cases this week, the most yet.
The director of the U.S. Centers for Disease Control says it could get much worse still. He spoke yesterday in Sierra Leone.
DR. THOMAS FRIEDEN, Director, Centers for Disease Control and Prevention: If we don’t stop it here, we’re going to be dealing with it for years around the world. But we can still stop it.
HARI SREENIVASAN: And a top official with Doctors Without Borders called today for a far greater international response. Otherwise, he said, “I don’t see how we’re going to control the outbreak.”
For more on all this, I am joined by Stephen Gire. He is a research scientist with the Broad Institute and Harvard University and a lead author on the study published yesterday in “Science.”
So, Stephen, tell me, how is it that you were able to go back and trace this spread of the most recent case of Ebola virus to one specific event?
STEPHEN GIRE, Harvard University: We used both epidemiological data, which is data that’s collected about people and who they’re in contact with when a disease happens, and then we paired this with genetic data that we collected from patient samples.
And we actually sequenced the full genome of the virus from 78 individual patients. And so we used this data and the mutations that are there within that virus to actually build the sort of family tree that allows us to see, for one, how these viruses are related to each other, but then to see how we can trace them back to their origin.
HARI SREENIVASAN: So, when you got to the root of this particular tree, what is it about a funeral or what about African burial customs that made this the perfect ground for Ebola to spread?
STEPHEN GIRE: On May 25 in Sierra Leone on the border between Guinea and Sierra Leone, there was a funeral that took place of a traditional healer who had been treating Ebola patients in Guinea, and she had herself become sick and died of Ebola.
And it was at this funeral where a large number, a little over a dozen members, at the funeral were actually infected. And we know this from epidemiological data. But we also know that an attendant from that funeral was — actually came into the hospital at Kenema Government Hospital, which is where we worked, and was diagnosed.
And so we were then able to go out and find other people at that funeral and then start to build this phylogenetic tree or this family tree of what the virus actually looked like.
HARI SREENIVASAN: So, is it because people come in contact with a body that’s infected?
STEPHEN GIRE: That’s correct.
You know, the burial practices in a lot of African countries, the people or family — the friends or family that know the deceased person usually take part in preparing the body and washing it. And just like funerals here in America and around the world, we often interact with the body once it’s dead. There’s open-casket viewings and many people actually touch the body.
The same thing is true in Africa as well, and that can be a part of spreading this disease.
HARI SREENIVASAN: You know, one of the most serious costs of this paper was that five of your colleagues on the ground became sick and died in the work that they were doing.
STEPHEN GIRE: Yes, it’s really very tragic.
And I was on the ground in Sierra Leone, in Kenema, in early July. And shortly after I returned and started processing the samples that we had collected for the study, we got word that a few of the members that had been a part of this project had become sick.
And, at that time, it was sort of numbing, and you didn’t quite accept the fact that they were sick, and you had hope that they would survive. And so you kept pushing and kept doing your work. And, you know, then word would come that somebody had died, and it would just sink in deep.
But, you know, just as hard as people have been working on the ground, we have also been trying to work very hard here to try to get this information out to the public, out to the scientific community, so that it can be used in this outbreak and other outbreaks. So we have really tried to honor their memory by continuing to work really hard and push this information out so that it makes a difference.
HARI SREENIVASAN: All right, Stephen Gire, thanks so much for your time and your research.
STEPHEN GIRE: Thank you.