How Likely Is It That Bird Flu Will Spread to the U.S.?

This is a partial transcript of "Special Report With Brit Hume" from Oct. 10, 2005, that has been edited for clarity.

Watch "Special Report With Brit Hume" weeknights at 6 p.m. EDT.

BRIT HUME, ANCHOR:

(BEGIN VIDEO CLIP)

GEORGE W. BUSH, PRESIDENT OF THE UNITED STATES: I am concerned about avian flu. I am concerned about what an avian flu outbreak could mean for the United States and the world. The reporting needs to be not only on the birds that have fallen ill, but also on tracing the capacity of the virus to go from bird to person.

(END VIDEO CLIP)

HUME: There's been some pretty scary talk of a bird flu pandemic, with the possibility of deaths in the millions in this country. The president made clear at that news conference that he's taking it seriously and wondered how he could enforce a quarantine, if that were needed.

But how likely is it that bird flu will spread to the U.S.? For answers, we turn to David Heyman, a homeland security expert at the Center for Strategic and International Studies.

Welcome, sir.

DAVID HEYMAN, CENTER FOR STRATEGIC/INTERNATIONAL STUDIES: Nice to be with you.

HUME: I hope I pronounced your name correctly. Good.

So, first of all, bird flu, avian flu, is a disease which humans can get from birds?

HEYMAN: That's right. Avian flu is a chicken flu, basically. And humans have flu every fall. We're reaching that season right now. Chickens get flu, as well. And avian flu, right now it's transmitted from chicken to people, but not necessarily from people to people.

HUME: And how is it transmitted, because you eat chicken, or because you get close to the chickens?

HEYMAN: Close to the chickens, to the chicken excrement, or things like that, chicken spit, actually, and that kind of thing...

(CROSSTALK)

HUME: And how contagious is it, bird to human?

HEYMAN: Bird to human, it's contagious.

HUME: Is it easily contagious?

HEYMAN: If you come into contact with it, you put it into your own membranes, if you get it in your mouth or your nose, you breathe in some of the particles, there's a possibility of getting it. We haven't...

HUME: And how deadly is it?

HEYMAN: Well, we have no natural immunity to avian flu. And that's one of the reasons that people are so concerned about it. Humans don't have natural immunity to it.

HUME: So if you get sick from it, what are the symptoms?

HEYMAN: Well, like any other flu.

HUME: So it's a flu where you -- it attacks your system, you get the fever, your digestive apparatus goes crazy, you get it in your chest?

HEYMAN: Sure. And you get your respiratory -- you can have respiratory failure. And one of the reasons...

HUME: So, presumably, elderly people through respiratory problems particularly vulnerable, as with other forms of flu?

HEYMAN: Again, depending upon what kind of flu it is, yes, it's very much like any other kind of flu.

HUME: All right. So, now, if we don't get birds with flu into this country, we're safe, so far, correct?

HEYMAN: Well, first, let's be very clear. There is no imminent risk of it coming into this country. What we've seen recently is an increase of birds getting this flu in Asia and, consequently, some people getting this flu. There are about 100 cases of people in Asia...

HUME: Worldwide?

HEYMAN: Worldwide.

HUME: Right. So these flu victims in Asia are all there is?

HEYMAN: That's right. There's been a couple of cases over the last couple of years in the United States, two cases, as I recall.

HUME: How did they get it?

HEYMAN: They got it from chickens or from poultry.

HUME: Outside this country, supposedly?

HEYMAN: Either outside this country or from a bird, like, flying overhead. I'm not quite clear exactly where these two cases -- one was in West Virginia, one was in, I believe, New York.

HUME: All right. Now, this flu, if I caught this flu from a chicken...

HEYMAN: Yes.

HUME: ... and I started talking to you as we are here, what would be the likelihood you could get it from me?

HEYMAN: OK, right now, there's no -- it's very rare for a human-to-human transfer. That is to say...

HUME: And why is that?

HEYMAN: The avian flu that they're worried about right now is called H5N1. Right now, it doesn't appear to be transferring human to human. There may be one or two cases.

HUME: So it could go from birds to humans, but, so far as we know, not from humans to humans?

HEYMAN: Very rare. They've seen maybe one or two cases of this. If it does becomes human-to-human transfer...

HUME: How does that happen?

HEYMAN: Well, the genes mutate. Flu, as you know, changes every year...

HUME: I know that.

HEYMAN: We get vaccines every year. So if it changes -- and in this particular flu, experts have seen, it's quite -- it has a great propensity to acquire other genes from other viruses. So if it acquired a gene from a virus that was human-to-human transmissible, that is to say its DNA was rearranged, it mutated...

HUME: But how likely is that, that that will happen?

HEYMAN: Well, that happens -- it happens frequently and throughout history.

HUME: In the sense that strains of flu change?

HEYMAN: Absolutely.

HUME: Year over year?

HEYMAN: Year to year they change. And across history, the worst flues we have seen are avian flues. The 1918 flu was an avian flew; 1957, avian flu; 1968, avian flu. Those are the three worst we've seen in the 20th century.

You usually get three or four pandemics in a century. That's one of reasons that people are paying more attention to it. It's about time, in terms of the frequency of pandemic flues, that we see another one. This particular virus, H5N1...

HUME: You say it's about the time. Is that something because, in the time cycles, it turning...

(CROSSTALK)

HEYMAN: Historically.

HUME: ... up that way, or is it because there's something about flu that makes it recreate itself in some particularly lethal form every certain number of years?

HEYMAN: It's a historical cycle that we're seeing, every three...

(CROSSTALK)

HUME: It sort of like odds, though, right?

HEYMAN: It is. It's very much like odds. And as you don't see one from year to year, the odds go up, because you do sort of see three or four in a century.

This particular one, H5N1, that they've seen now cropped up in 1997. We saw in 2003. It showed up again and started spreading to nine other countries in Asia. Last year in Vietnam, we saw a person get sick, and more people started to get sick, from direct contact to poultry.

Because it can mutate, because it has the possibility of becoming human-to-human transfer, and there's no known immunity, that's why people are concerned and they've got to watch it. If it becomes human-to-human transmissible, then there's a likelihood of a pandemic.

HUME: But the pandemic is not likely to occur because people keep getting it from birds? It's likely to become...

HEYMAN: If it mutates.

HUME: ... if it mutates into a human transmissible form.

HEYMAN: That's right. That's right.

HUME: And that hasn't happened yet?

HEYMAN: Hasn't happened. They've seen a couple of cases where it looks like human-to-human transmission.

HUME: Now, this -- does the flu virus -- they change all the time. We know that. But is this the way they normally change, from one kind of being -- being transmissible in one way to another...

HEYMAN: Sure, we've seen that.

HUME: ... or is it just like as likely this flu will change itself in some another way?

HEYMAN: No, no, we've seen that happen. That's a historical pattern. The flu virus is known to do this. This particular flu virus does this. So it is something that we have seen.

HUME: So how can it be stamped -- last question. We don't have much time.

HEYMAN: Right.

HUME: How can it be stamped out where it is?

HEYMAN: OK. That's why the president and the State Department held a meeting last week, 80 countries. We've got to have international cooperation. You've got to cull the poultry. You've got to see when the chickens are getting sick, stop them there.

HUME: Kill them.

HEYMAN: Kill the chickens. If you don't, it then starts going into people. You start seeing going into people.

HUME: But in the meantime, my chicken tenders are OK?

(LAUGHTER)

HEYMAN: Your chicken tenders are OK.

HUME: All right, David Heyman, thanks very much.

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