‘You Don’t Want This Going Places’

Few things in life are scarier than Ebola. The virus has killed 9 of 10 victims in some outbreaks, and the effects are particularly gruesome—the bug causes massive bleeding. Ever since the first outbreaks in 1976, which erupted simultaneously in Zaire (now the Democratic Republic of the Congo) and Sudan, scientists had identified a total of four strains. Now there's a fifth. The outbreak earlier this month in Uganda has claimed 22 lives, including a doctor in Kampala, raising fears of an urban outbreak and causing rumors that the virus is a milder type that could spread more easily beyond Uganda and the African continent. Tom Ksiazek, chief of the pathogen branch of the Centers for Disease Control in Atlanta spoke with NEWSWEEK's Fred Guterl about how dangerous the outbreak may be and what scientists are doing to investigate. Excerpts:

NEWSWEEK: How is this virus different from the four other known strains of Ebola?
Tom Ksiazek: This virus is not like any of the four other ones. It's about as different from the other four as they are from each other.

How do you know?
That's based on preliminary information about the [genetic] sequence of the virus itself. These are RNA viruses, so we're looking at the [nucleotide] base composition of small pieces of the virus. We've managed to isolate the virus and are growing it in cell cultures. We're still working on getting more sequencing.

What have you learned about this particular strain?
There's been a lot of speculation in press reports about it being less pathogenic, or perhaps not causing as much bleeding [as other strains]. I've seen other people speculating that this will make it more difficult to control. Our perspective is, you need data to say those things. Specifically when you're dealing with a new virus. You have to develop your data as you go along. You want to probably limit your data to those who you can demonstrate are really patients who have been infected with the virus. It's very early in the process now. We've diagnosed a few patients in our lab, and those are the only patients we really know are Ebola patients.

You mean many people reported as victims of this Ebola outbreak may be sick with some other disease?
You're seeing reports from Uganda that there's—you name a number—79 patients and 22 deaths. How many of those patients are really known to [have the] Ebola virus? There's a case definition that's developed that says, "This guy's got a headache and four or five other symptoms." There are a lot of other things that will give you symptoms like that.

Like what?
If you've ever had a serious case of flu, you'd be included in that group. Or early malaria, for that matter.