Bird Flu Transferred from Human to Human Researchers confirm the human-to-human transmission of avian influenza, though health experts said that there were no signs that the virus had mutated into an easier-to-transmit form.
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Bird Flu Transferred from Human to Human

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Bird Flu Transferred from Human to Human

Bird Flu Transferred from Human to Human

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IRA FLATOW, host:

This is TALK OF THE NATION: SCIENCE FRIDAY. I'm Ira Flatow. Coming up a bit later in the hour, crops and carbon dioxide and the mystery of the vanishing electric car. But first, a bit of intrigue about the bird flu.

Last week, researchers said they had confirmed that in a family in Indonesia, the avian flu had definitely spread from person to person rather than being spread through contact with infected poultry, in this case. Elsewhere, investigators have said that several people in Azerbaijan likely contracted bird flu from infected swans. This would be the first reported case due to contact with wild birds rather than animals being raised for agriculture.

So, do these firsts mean that the bird flu has found an easier way to spread? And perhaps does it mean that we're seeing the first cases of a newer, more deadly virus? Joining me now to talk about it is Robert Webster. He is a member of the faculty in the Department of Infectious Diseases at St. Jude's Children's Hospital in Memphis, Tennessee. He joins us by phone. Welcome to the program, Dr. Webster.

Dr. ROBERT WEBSTER (Department of Infectious Diseases, St. Jude Children's Research Hospital): Delighted to be with you.

FLATOW: Thank you. Let me go to the $64-question first, that, you know, the worst-case scenario, does this mean in these cases that we're possibly seeing the virus mutating to a form where it might more easily spread between human to human?

Dr. WEBSTER: No, I don't believe so. I - the human host differs enormously from person to person, and I think that this is just a unique cluster of humans.

FLATOW: Mm-hmm. In other words, we know that it's possible to spread from human to human but very difficult, and this is a case of just one of those cases.

Dr. WEBSTER: Just one of those cases. It's extremely difficult for humans to be infected in the first place, and this is not the first cluster we've seen. It's the biggest cluster so far, of seven people. And it's to do with the genetics of humans, and so it's not surprising. We're likely to see it again.

FLATOW: Mm-hmm. So is it possible there are other cases that just have not gone unreported of this kind of spread?

Dr. WEBSTER: No, we believe that there are very few additional cases that occur.

FLATOW: Mm-hmm.

Dr. WEBSTER: The studies in families and relations around these cases don't show additional spread, so we do not believe that there's been much additional spread in humans at all in either Indonesia, China, or elsewhere in the world.

FLATOW: Mm-hmm. Let's talk about the reports of people catching the virus from wild birds, in this case, the swans rather than...

Dr. WEBSTER: That would be unique, and that was a very - that's the first time ever we've had direct evidence of transmission from a wild bird to a human.

FLATOW: Mm-hmm. Is this a cause for worry?

Dr. WEBSTER: Oh, it's certainly a cause for worry, but again, this is a unique case where we believe that in the depth of winter, when the virus was moving rapidly through that area of Azerbaijan, that swans, dead swans, were occurring, and the people went and plucked the down and feathers off those dead birds. And so these are a unique set of circumstances that are not likely to happen frequently.

FLATOW: Mm-hmm. So this is - was this a case where they were - is a typical very close contact but this time with wild birds?

Dr. WEBSTER: This is a case of very close contact with wild birds. Yes, indeed.

FLATOW: Mm-hmm. How significant a role do the wild birds play? Are we learning, you know, whether that is going to be a route that it might be more likely spread through or possibly through other routes?

Dr. WEBSTER: Well, the wild bird route is - the wild birds were certainly involved in the spread of this virus from China through Central Asia into Turkey and Europe, probably not wild birds alone. The industry is integrated and probably the integrated industry plus the wild birds. But the wild birds were certainly involved, and there's no doubt that this virus is now in wild birds in Europe and Asia.

FLATOW: Mm-hmm.

Dr. WEBSTER: And, of course, the question everyone asks me at the moment, is when is it going to arrive through Alaska?

FLATOW: And you tell them?

Dr. WEBSTER: I don't think that this is going to occur so easily, because when we look at the biology of influenza in birds, and in the continents, the viruses in Europe and Asia are a different family from those in the Americas. And there's not a lot of transmission between these two sites.

FLATOW: Mm-hmm.

Dr. WEBSTER: Otherwise these two super families of influenza would not have developed over thousands of years. It could happen, however, and it does happen...

FLATOW: Is it - I'm sorry, go ahead.

Dr. WEBSTER: I think a more likely scenario is that it's going to come in in smuggled birds. We have so many of these live markets for pet birds, and, you know, the smuggling of pet birds, wild birds, is second only to drugs, incidentally.

FLATOW: No kidding. No kidding.

Dr. WEBSTER: So we have to be much aware of that.

FLATOW: I know there are cases, are there not, of not smuggled birds but just even pets coming through quarantine at airports who have been shown to have the avian flu and have died right at the airport.

Dr. WEBSTER: It occurred in Europe, into Germany, and a case earlier into England, but that went into quarantine and didn't spread out.

FLATOW: Mm-hmm.

Dr. WEBSTER: So it's - there's precedent for these smuggled birds to occur.

FLATOW: Mm-hmm. There's a report out today on the wires from Reuters has a report from the World Health Organization, and I'll read a little bit of it for you. It says, the risk of bird flu mutating into a form more easily spread between people is still high, and there could be an upswing in human infections at the end of this year - saying that there's a pattern here that's very similar to the last pandemic, the 1918, 1919 Spanish flu, in which you had the swelling of cases that happened at the - into the winter and in the spring seasons in the Northern Hemisphere.

Dr. WEBSTER: Yeah, well, we had been following this bird flu since 1996, and there's no doubt that the winter months are when it spreads, and so the - we're in the summer period in the Northern Hemisphere. So we're in a quiescent period at this time, although there's very worrying things going on in Indonesia and in the wild birds in Siberia. It's not risk-free at the moment, at all. Come next winter, the possibility increases much more strongly in the winter months.

FLATOW: Mm-hmm. What do you think of the letter last week in the New England Journal saying that what had been reported as SARS may actually have been an early case of Avian Flu?

Dr. WEBSTER: No big surprise. I think that this information was about in Asia for some time and at the time that incident occurred, Asia was so busy with SARS that it was frozen away and not given a lot of attention. And so it's no big surprise.

FLATOW: Mm hmm. Where do we stand on coming up with a vaccine these days? I know there are a lot of different efforts. What's the status of a flu vaccine?

Dr. WEBSTER: Oh, the vaccines are being developed and vaccines are being developed here at St. Jude Hospital and at CDC and in London. And we have vaccine seed stocks available for the latest variants that are out there. The difficulty is, which one of these three different families that have developed is going to be the one that travels human-to-human? If it does, which one's the correct one?

And so at this stage we have prepared vaccines against each one, which will go now to the manufacturers to get experience with them and so on. So we have the technology for making these vaccines, and we have to watch what's happening in nature to determine that we stay abreast of the virus changing, because it's continuing to evolve all the time.

FLATOW: I'm going to see if I can get a quick question in from a listener. Anna in St. Louis. Hi, Anna.

ANNA (Caller): Hi. I was curious when you were talking about this family being infected by picking feathers off of a swan. What would say that bird feathers in the down quilts that are being sold from China - do we have to worry about that?

Dr. WEBSTER: I don't believe so. This virus is reasonably heat-stable, but not that heat-stable. It wasn't the feathers so much as the fecal material and tissue coming off with the feathers. The feathers themselves would be contaminated with fecal material. That's the most likely source of the virus being transmitted to those people. Down, especially if it's treated with gamma irradiation or with just sunlight for a reasonable time - we know that the virus isn't transmitted well in the summertime, so the risk is very, very small.

FLATOW: And, as you say, it's very, very hard - it's a virus that's very hard to catch.

Dr. WEBSTER: It is very...

FLATOW: ...unless you're really in close contact for awhile with these animals or other people.

Dr. WEBSTER: Or if you are a member of one of these unique families in the world that we don't fully understand.

FLATOW: Mm hmm. So this being the wintertime, south of equator then, we'll be keeping a close eye on what's going on in Indonesia and other countries?

Dr. WEBSTER: That's correct.

FLATOW: Mm hmm. Well, Doctor, I want to thank you for taking time to talk with us and I'm sure this is the kind of stuff that you'll be watching and we'll be asking you to come back and, if you don't mind being gracious enough to come back and talk about it as we learn more about it.

Dr. WEBSTER: Well, I hope that you don't have to talk to me again, but we mustn't become complacent because this is a rather bad virus.

FLATOW: And people are - you know, that is the point - that is one of the problems. You might shout, you know - cry wolf - and people won't listen and then this'll break out and they'll be, you know, unprepared.

Dr. WEBSTER: Well, the public may become disinterested, but the scientific community realizes the similarity of this virus to the 1918 - the point that you made - and so, we are very conscious of the danger to humanity. It's a great danger already to the chicken poultry industry of the world.

FLATOW: Robert Webster, thank you very much for taking time to talk with us.

Dr. WEBSTER: You're most welcome.

FLATOW: He's a member of the faculty in the Department of Infectious Diseases at St. Jude's Children's Research Hospital in Memphis.

And we're going to take a break, and stay with us, we've got lots more to talk about. Don't go away.

I'm Ira Flatow. This is TALK OF THE NATION: SCIENCE FRIDAY from NPR News.

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