|REVISITING THE 1918 FLU|
March 24, 1997
ELIZABETH FARNSWORTH: That disease is influenza and specifically the 1918 flu virus that killed 675,000 Americans and more than 20 million people around the world. The outbreak probably started in the United States at an army base in the Midwest and then spread to Europe in the lungs of soldiers headed for World War I. Scientists have tried for years to find traces of the virus to study what made it so lethal. Late last week, a group of researchers reported in "Science Magazine" they'd succeeded in their search. Here to tell us about are Dr. Jeffrey Taubenberger, chief of molecular pathology at the Armed Forces Institute of Pathology.
Doctor, I remember my grandfather in Kansas saying that so many people died at Fort Riley that they didn't have coffins for them in 1918. Is that the way it was all over the country?
DR. JEFFREY TAUBENBERGER, Armed Forces Institute of Pathology: Yes, it was clearly catastrophic, not only in the United States but really just exploded as an incredible episode all throughout the world.
ELIZABETH FARNSWORTH: How many people now--I reported more than 20 million--but how many do you think in the latest research?
DR. JEFFREY TAUBENBERGER: The conservative estimate is 21 million people, but people suggest that it may be forty to fifty million people actually died worldwide. Some current research suggests that almost 20 million people died in India alone.
ELIZABETH FARNSWORTH: Why? What made it so lethal? Is that what you're trying to figure out?
DR. JEFFREY TAUBENBERGER: That certainly is what prompted us to begin this work. This was clearly one of the worst, if not "the" worst infectious disease outbreak in all human history. And until this work nothing was known directly about the virus that caused this infection.
ELIZABETH FARNSWORTH: They died--people died very quickly. Their lungs filled up. Is that what happened?
DR. JEFFREY TAUBENBERGER: Certainly. A subset of patients died extremely quickly, within two or three or four days of symptoms. And one of the problems was an accumulation of massive amounts of fluid in the lungs, pulmonary edema, and these patients in a sense literally drowned. Other people died of secondary infections with bacterial pneumonia. Antibiotics were not known to exist in 1918, and there was no way to treat those secondary infections.
ELIZABETH FARNSWORTH: So tell us how you began your search. Where did you search, and what were you looking for?
DR. JEFFREY TAUBENBERGER: The Armed Forces Institute of Pathology in Washington had been collecting surgical and autopsy pathology cases for over a hundred years. And once it became clear to us that about 70 autopsy cases of victims of the 1918 flu were available in our files, we would take a look to find if any of the cases contained viral genetic material.
ELIZABETH FARNSWORTH: Which would be like tissues from the bodies that were on file in formaldehyde?
DR. JEFFREY TAUBENBERGER: That's correct. Not in formaldehyde. The tissues at the time of autopsy were sectioned and fixed in formaldehyde and then imbedded in paraffin wax and were actually stored in these little blocks of wax just at room temperature on shelves for 80 years.
ELIZABETH FARNSWORTH: And so what did you do? You found a private whose lungs--you looked at tissues from his lungs?
DR. JEFFREY TAUBENBERGER: That's right. We looked at about 35 cases, and most of them had courses in which they died of secondary bacterial pneumonia. A subset of cases died very quickly. And we were looking for patients that died very quickly after the onset of symptoms in order to try to capture the virus while it was still present and replicating. And of those six cases we examined only one was positive.
ELIZABETH FARNSWORTH: What did you find exactly?
DR. JEFFREY TAUBENBERGER: Well, we found small fragments of the viral RNA, the genetic material, in this case. The tissue is--the genetic material is quite degraded in this sample, and so we can only look at very small pieces at a time and, in a sense, put them together like a puzzle. But what we find is that it's a virus that does not match any strain of influenza virus isolated since, but it is most related to the kind of influenzas that infect swine, suggesting that this influenza entered the human population after being passaged through pigs.
ELIZABETH FARNSWORTH: You are now trying to put together more of the DNA. And what are you looking for exactly? Are you trying to figure out what there was in this DNA that made it so lethal to humans?
DR. JEFFREY TAUBENBERGER: Right. The ultimate goal of the project would be to see if there is a genetic basis for why this particular virus was so virulent. Influenza viruses mutate. Continually new strains arise, which is why vaccines have to be made every year to match the current strain. And this kind of thing could certainly happen again. And if we could get a global understanding of how you would relate the genetic structure of a virus to its virulence, we would be able to predict future epidemics.
ELIZABETH FARNSWORTH: How could it happen again if the flu viruses--there have been two pandemics of flu--with what ‘68 and ‘57, something like that--
DR. JEFFREY TAUBENBERGER: That's correct.
ELIZABETH FARNSWORTH: Pandemic being a worldwide epidemic. But they weren't nearly as virulent. Why would you think that there would be another virulent epidemic like that one?
DR. JEFFREY TAUBENBERGER: Well, certainly we can say that there will be new pandemics. That's certainly the history of influenza viruses. And it's--it's possible that there would be a pandemic of this magnitude. One could hope that there wouldn't be, but I think we should be prepared for that possibility.
ELIZABETH FARNSWORTH: Explain why there could be and why it would develop in a pig and then why it would become that virulent in humans.
DR. JEFFREY TAUBENBERGER: Well, I can only say that it happened once, and so it is possible that it would happen again. Unfortunately, we don't have an answer as to why the virus was so lethal now, but this is really the beginning of the story. And we only have about 5 percent of the gene structure of the virus, but we hope to eventually accumulate more information that would be useful.
ELIZABETH FARNSWORTH: What comes next? There are groups looking for live virus, right? Tell us about that.
DR. JEFFREY TAUBENBERGER: Well, there are other groups who have been interested in recovering virus. One group is interested in recovering virus from miners who are frozen in the permafrost in Spitzburg and in Norway. It's possible that there will be a case that has the genetic material of the virus. It would even be conceivably possible there would be a body that would have live virus in it.
ELIZABETH FARNSWORTH: And then if that is found, or if you're able to map the whole gene structure, then that will allow you--would it allow you, do you think, to find something which could stop the virus, or more that when you see it, you'll know what it is, you'll know that it's another lethal virus?
DR. JEFFREY TAUBENBERGER: Right. That would be the primary interest would be to use this information as a predictor for when future strains were likely to be so infectious. It's still possible that even if we had the full gnomic sequence in front of us, the whole structure of the virus, that we actually wouldn't have an answer. But I think that there are so many unusual features about this virus that there must be a genetic basis for its virulence. And hopefully in the future that kind of correlation can be made.
ELIZABETH FARNSWORTH: Well, Doctor, good luck. I hope you find out what it is, and that you're able to predict if it's on it's way again. Thank you so much.
DR. JEFFREY TAUBENBERGER: Thank you.